Glyceraldehyde-3-phosphate dehydrogenase: activity inhibition and protein overexpression in rotenone models for Parkinson's disease

Rotenone, a widely used pesticide and an environmental risk factor for Parkinson's disease (PD), induces nigrostriatal injury, Lewy body-like inclusions, and Parkinsonian symptoms in rat models for PD. Our previous data indicated that glyceraldehyde-3-phosphate dehydrogenase (GAPDH) overexpression and glycolytic inhibition were co-current in rotenone-induced PC12 (rat adrenal pheochromocytoma cells) cell death. However, whether GAPDH overexpression plays any role in dopaminergic neurodegeneration in vivo remains unknown. In this study, we have found that GAPDH overexpression and GAPDH-positive Lewy body-like aggregates in nigral dopaminergic neurons while nigral GAPDH glycolytic activity decreases in rotenone-based PD animal models. Furthermore, GAPDH knockdown reduces rotenone toxicity significantly in PC12. These in vitro and in vivo data suggest that GAPDH contributes to the pathogenesis of Parkinson's disease, possibly representing a new molecular target for neuroprotective strategies and alternative therapies for PD.

Upregulation of VEGF-A and CD24 gene expression by the tGLI1 transcription factor contributes to the aggressive behavior of breast cancer cells

The Hedgehog signaling pathway is one of the most dysregulated pathways in human cancers. The glioma-associated oncogene homolog 1 (GLI1) transcription factor is the terminal effector of the Hedgehog pathway, frequently activated in human breast cancers and an emerging target of breast cancer therapy. While somatic mutations in the human GLI1 gene have never been reported in any cell or tumor type, we recently uncovered the existence of a novel alternatively spliced, truncated GLI1 (tGLI1) that has an in-frame deletion of 41 codons spanning the entire exon 3 and part of exon 4 of the GLI1 gene. Using glioblastoma models, we showed that tGLI1 has gained the ability to promote glioblastoma migration and invasion via its gain-of-function transcriptional activity. However, the pathological impact of tGLI1 on breast cancer remains undefined. Here, we report that tGLI1 is frequently expressed in human breast cancer cell lines and primary specimens we have examined to date, but is undetectable in normal breast tissues. We found for the first time that tGLI1, but not GLI1, binds to and enhances the human vascular endothelial growth factor-A (VEGF-A) gene promoter, leading to its upregulation. Consequently, tGLI1-expressing MDA-MB-231 breast cancer cells secret higher levels of VEGF-A and contain a higher propensity, than the isogenic cells with control vector and GLI1, to stimulate in vitro angiogenesis of human vascular endothelial cells. We further showed that tGLI1 has gained the ability to enhance the motility and invasiveness of breast cancer cells in a proliferation-independent fashion and that this functional gain is associated with increased expression of migration/invasion-associated genes, CD24, MMP-2 and MMP-9. tGLI1 has also acquired the property to facilitate anchorage-independent growth of breast cancer cells. Collectively, our results define tGLI1 as a gain-of-function GLI1 transcription factor and a novel mediator of the behavior of clinically more aggressive breast cancer.

Cancer targeting Gene-Viro-Therapy of liver carcinoma by dual-regulated oncolytic adenovirus armed with TRAIL gene

Liver cancer is a common and aggressive malignancy, but available treatment approaches remain suboptimal. Cancer targeting Gene-Viro-Therapy (CTGVT) has shown excellent anti-tumor effects in a preclinical study. CTGVT takes advantage of both gene therapy and virotherapy by incorporating an anti-tumor gene into an oncolytic virus vector. Potent anti-tumor activity is achieved by virus replication and exogenous expression of the anti-tumor gene. A dual-regulated oncolytic adenoviral vector designated Ad·AFP·E1A·E1B (Δ55) (Ad·AFP·D55 for short thereafter) was constructed by replacing the native viral E1A promoter with the simian virus 40 enhancer/α-fetoprotein (AFP) composite promoter (AFPep) based on an E1B-55K-deleted construct, ZD55. Ad·AFP·D55 showed specific replication and cytotoxicity in AFP-positive hepatoma cells. It also showed enhanced safety in normal cells when compared with the mono-regulated vector ZD55. To improve the anti-hepatoma activities of the virus, the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene was introduced into Ad·AFP·D55. Ad·AFP·D55-TRAIL exhibited remarkable anti-tumor activities in vitro and in vivo. Treatment with Ad·AFP·D55-TRAIL can induce both autophagy owing to the Ad·AFP·D55 vector and caspase-dependent apoptosis owing to the TRAIL protein. Therefore, Ad·AFP·D55-TRAIL could be a potential anti-hepatoma agent with anti-tumor activities due to AFP-specific replication and TRAIL-induced apoptosis.

Lithium-7 NMR Studies of Li1−xCoO2 Battery Cathodes

Lithium-deficient cathode materials Li1-xCoO2 where x = 0.1, 0.4 and 0.6 were prepared electrochemically from the stoichiometric parent compound (x = 0.0).The materials were observed to be air-stable, and x-ray diffraction characterization yielded good agreement with the in situ studies of Dahn and co-workers, regarding changes in lattice parameters. In addition to both static and magic angle spinning (MAS) 7Li NMR, measurements, the samples were investigated by EPR and cobalt K-edge NEXAFS. The removal of Li is accompanied by compensating electrons from the Co d-orbitals, asevidenced by both shifts in the NEXAFS peak and the observation of EPR signals due to spins localized on the Co ions. These spins, in turn, result in dramatic 7Li chemical shifts (89 ppm for x = 0.6) and line broadening. Whereas MAS analysis of Li0.9CoO2 indicates two magnetically inequivalent Li sites, the spectra becometoo broad to resolve different sites for higher values of x. Finally NMR linewidth and spinlattice relaxation measurements as a function of temperature suggest a modest increase in Li+ ion mobility for Li-deficient samples as compared to the parent compound.

A Novel Technique For Rtp Annealing Of Compound Semiconductors

We introduce for the first time a novel rapid thermal processing (RTP) unit called ZapperTM, which has recently been developed by MHI Inc. and the University of Florida for high temperature thermal processing of semiconductors. This ZapperTM unit is capable of reaching much higher temperatures (>1500 °C) than conventional tungsten-halogen lamp RTP equipment and achieving high ramp-up and ramp-down rates. We have conducted implant activation annealing studies of Si+-implanted GaN thin films (with and without an AIN encapsulation layer) using the ZapperTM unit at temperatures up to 1500 °C. The electrical property measurements of such annealed samples have led to the conclusion that high annealing temperatures and AIN encapsulation are needed for the optimum activation efficiency of Si+ implants in GaN. It has clearly been demonstrated that the ZapperTM unit has tremendous potential for RTP annealing of semiconductor materials, especially for wide bandgap compound semiconductors that require very high processing temperatures.

Longitudinal versus cross-sectional evaluations of leukocyte telomere length dynamics: age-dependent telomere shortening is the rule

BACKGROUND

Leukocyte telomere length (LTL) is considered a biomarker of human aging and based on cross-sectional studies it shortens with age. However, longitudinal studies reported that many adults display LTL lengthening.

METHODS

Using Southern blots, we compared cross-sectional rates of age-related LTL change across a ∼20 year age range with those based on longitudinal evaluations in three surveys (S1, S2, and S3) with three time intervals: S1-S2 (5.8 years), S2-S3 (6.6 years), and S1-S3 (12.4 years). Hierarchical linear modeling was used to explore LTL dynamics using LTL data from S1, S2, and S3.

RESULTS

Cross-sectionally, mean LTL shortenings were 24.6, 25.4, and 23.6 bp/y at S1, S2, and S3, respectively. Longitudinally, more variation was observed in the rate of LTL change during the shorter than longer follow-up periods. Furthermore, using simple differences in LTL, 14.4% and 10.7% of individuals displayed LTL lengthening during S1-S2 and S2-S3, respectively, but only 1.5% during S1-S3 (p < 0.001). The estimated mean rate of LTL shortening based on averaging empirical Bayes' estimates of LTL from a parsimonious hierarchical linear modeling model was 31 bp/y with a range from 23 to 47 bp/y with none of the participants showing LTL lengthening over the average 12.4 years of follow-up.

CONCLUSIONS

As aging displays a unidirectional progression, it is unlikely that LTL elongates with age. LTL elongation in longitudinal studies primarily reflects measurement errors of LTL in relation to the duration of follow-up periods.

Metformin regulates the incretin receptor axis via a pathway dependent on peroxisome proliferator-activated receptor-α in mice

AIMS/HYPOTHESIS

Metformin is widely used for the treatment of type 2 diabetes. Although it reduces hepatic glucose production, clinical studies show that metformin may reduce plasma dipeptidyl peptidase-4 activity and increase circulating levels of glucagon-like peptide 1 (GLP-1). We examined whether metformin exerts glucoregulatory actions via modulation of the incretin axis.

METHODS

Metformin action was assessed in Glp1r(-/-), Gipr(-/-), Glp1r:Gipr(-/-), Pparα (also known as Ppara)(-/-) and hyperglycaemic obese wild-type mice with or without the GLP-1 receptor (GLP1R) antagonist exendin(9-39). Experimental endpoints included glucose tolerance, plasma insulin levels, gastric emptying and food intake. Incretin receptor expression was assessed in isolated islets from metformin-treated wild-type and Pparα(-/-) mice, and in INS-1 832/3 beta cells with or without peroxisome proliferator-activated receptor (PPAR)-α or AMP-activated protein kinase (AMPK) antagonists.

RESULTS

In wild-type mice, metformin acutely increased plasma levels of GLP-1, but not those of gastric inhibitory polypeptide or peptide YY; it also improved oral glucose tolerance and reduced gastric emptying. Metformin significantly improved oral glucose tolerance despite loss of incretin action in Glp1r(-/-), Gipr(-/-) and Glp1r(-/-) :Gipr(-/-) mice, and in wild-type mice fed a high-fat diet and treated with exendin(9-39). Levels of mRNA transcripts for Glp1r, Gipr and Pparα were significantly increased in islets from metformin-treated mice. Metformin directly increased Glp1r expression in INS-1 beta cells via a PPAR-α-dependent, AMPK-independent mechanism. Metformin failed to induce incretin receptor gene expression in islets from Pparα(-/-) mice.

CONCLUSIONS/INTERPRETATION

As metformin modulates multiple components of the incretin axis, and enhances expression of the Glp1r and related insulinotropic islet receptors through a mechanism requiring PPAR-α, metformin may be mechanistically well suited for combination with incretin-based therapies.

Taxonomic identification of a novel strain of Streptomyces cavourensis subsp. washingtonensis, ACMA006, exhibiting antitumor and antibacteria activity

Taxonomically diverse and genetically specialized, marine microorganisms have great potential in generating bioactive substances. A previous study isolated a novel actinomycete strain designated ACMA006 and revealed that the fermentation broth of ACMA006 (FBA6) significantly inhibited the growth of a series of tumor cell lines. The present study examined various characteristics of the ACMA006 strain, including its morphological, physiological, and biochemical nature, and the 16S rDNA gene sequence of ACMA006 and biological activity of FBA6. The ACMA006 strain grew at an optimal temperature of 28°C on nearly all media tested, except for Czapek's agar, producing an exuberant substrate and aerial hyphae. Phylogenetic analysis showed that the 16S rDNA gene sequence of ACMA006 was closely related to that of Streptomyces cavourensis subsp. washingtonensis, with a sequence similarity of nearly 100%. However, ACMA006 differed somewhat from Streptomyces cavourensis subsp. washingtonensis in terms of its morphological, physiological, and biochemical characteristics. According to a bioactivity assay, FBA6 strongly inhibited the growth of hepatocellular carcinoma cell line HepG2, while it was weakly cytotoxic to human normal hepatocytes LO2 according to an MTT assay. In addition, the growth of bacterial strains Bacillus subtilis and Staphylococcus aureus but not Escherichia coli, B. aerogenes, Pseudomonas fluorescence, and B. proteus was significantly suppressed by FBA6 as indicated by the filter paper disc method. Results of this study indicated that the strain ACMA006 represents a new strain of the Streptomyces cavourensis subsp. washingtonensis and that the active metabolites of this strain are candidates for utilization as anticancer or antibacterial agents.

Stanniocalcin 1 induction by thyroid hormone depends on thyroid hormone receptor β and phosphatidylinositol 3-kinase activation

CONTEXT

Thyroid hormone (TH) mediated changes in gene expression were thought to be primarily initiated by the nuclear TH receptor (TR) binding to a thyroid hormone response element in the promoter of target genes. A recently described extranuclear mechanism of TH action consists of the association of TH-liganded TRβ with phosphatidylinositol 3-kinase (PI3K) in the cytosol and subsequent activation of the PI3K pathway.

OBJECTIVE

The aim of this study was to examine the effect of TH, TRβ and PI3K on stanniocalcin 1 (STC1) expression in human cells.

DESIGN

We treated human skin fibroblasts with triiodothyronine (T3) in the absence or presence of the PI3K inhibitor LY294002, a dominant negative PI3K subunit, Δp85α, and the protein synthesis inhibitor cycloheximide (CHX). The role of the TRβ was studied in cells from patients with resistance to thyroid hormone (RTH). STC-1 mRNA expression was measured by real-time PCR.

RESULTS

We found an induction of STC1 by T3 in normal cells, but less in cells from subjects with RTH (2.7 ± 0.2 vs. 1.6 ± 0.04, P < 0.01). The effect of T3 was completely abrogated by blocking PI3K with LY294002 (3.9 ± 0.5 vs. 0.85 ± 0.5; P < 0.05) and greatly reduced after transfection of a dominant negative PI3K subunit, demonstrating dependency on the PI3K pathway.

CONCLUSION

These results establish STC1 as a TH target gene in humans. Furthermore, we show that STC1 induction by TH depends on both TRβ and PI3K activation.

Purification and characterization of a new D-galactose-specific lectin from the housefly, Musca domestica, and its antiproliferative effect on human K562 and MCF-7 tumor cells

In the present work, a D-galactose-specific lectin with novel N-terminal sequence was purified from Musca domestica L. (Diptera: Muscidae) pupae. The purification was performed using affinity chromatography, ultra-filtration, and HPLC. The haemagglutinating activity of M. domestica lectin was specifically inhibited by D-galactose. The haemagglutinating activity of this lectin was stable at temperatures up to 65 degrees C and in pH ranging from 4 to 8. Salts including FeCl(3) and MnCl(2) inhibited the haemagglutinating process, whereas NaCl, KCl, CaCl(2), MgCl(2), ZnCl(2), and AlCl(3) did not. By SDS-PAGE, purified M. domestica pupae lectin yielded a single band with a molecular weight of 40 kDa, with or without reduction of beta-mercaptoethanol, and it could be stained with Alcian Blue 8 GX. The morphology of purified lectin was observed by atomic force microscopy, which indicated that M. domestica lectin was an 8.27 nm high, globular shaped glycoprotein with a 1.41 nm high polysaccharide chain. In addition, antiproliferative activity of this lectin against tumor cells K562 and MCF-7 was determined with a colorimetric assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, which showed that the antiproliferative process was time- and dose-dependent with an IC(50) of 5.7 and 6.7 at 24 h, 5.5 and 6.4 at 36 h, 5.2 and 6.5 microM at 48 h, respectively.

The neuronal repellent SLIT2 is a target for repression by EZH2 in prostate cancer

The neuronal repellent SLIT2 is repressed in a number of cancer types primarily through promoter hypermethylation. SLIT2, however, has not been studied in prostate cancer. Through genome-wide location analysis we identified SLIT2 as a target of Polycomb group (PcG) protein EZH2. The EZH2-containing Polycomb repressive complexes bound to the SLIT2 promoter inhibiting its expression. SLIT2 was down-regulated in a majority of metastatic prostate tumors exhibiting a negative correlation with EZH2. This repressed expression could be restored by methylation inhibitors or EZH2-suppressing compounds. In addition, a low level of SLIT2 expression was associated with aggressive prostate, breast and lung cancers. Functional assays showed that SLIT2 inhibited prostate cancer cell proliferation and invasion. Thus, this study demonstrated for the first time epigenetic silencing of SLIT2 in prostate tumors, and supported SLIT2 as a potential biomarker for aggressive solid tumors. Importantly, PcG-mediated repression may serve as a precursor for the silencing of SLIT2 by DNA methylation in cancer.

Pharmacokinetics of methyl protodioscin in rats

Methyl protodioscin (MPD), a natural furostanol saponin, showed distinct antitumor activity and is distributed in many traditional Chinese medicines. The pharmacokinetics, distribution and excretion of MPD were first investigated after i.v. injection to rats in this study. The dose-dependent pharmacokinetics of MPD were characterized after i.v. injection (20, 40 and 120 mg/kg of MPD) to rats. A good linearity (r = 0.9989, P < 0.05) was found in the regression analysis of the AUC0-t -dose. The plasma concentrations of MPD declined rapidly with an elimination half-life (t1/2) from 25.56 to 29.32 min. The MPD kinetics was in line with one-compartment model after i.v. injection. 23.43% and 32.86% of MPD was recovered in urine and bile, respectively. The concentrations of MPD in plasma and most examined tissues 5 h after injection were close to or below the Low Limit of Quantification (LLOQ). This indicated that MPD was distributed and eliminated rapidly in rats.

Purification of lectin from larvae of the fly, Musca domestica, and in vitro anti-tumor activity in MCF-7 cells

A new lectin was purified from larvae of the fly, Musca domestica L. (Diptera: Muscidae) (MLL-2, 38 kDa) using affinity chromatography and HPLC. Anti-tumor activity of MLL-2 was demonstrated by its inhibition of proliferation of human breast cancer (MCF-7) cells in a time-and dose-dependent manner. The results of acridine orange staining indicated that MLL-2 caused apoptosis in MCF-7 cells. DNA fragmentation in MCF-7 cells has been detected by TUNEL. Flow cytometric analysis also demonstrated that MLL-2 caused dose-dependent apoptosis of MCF-7 cells through cell arrest at G2/M phase. The MLL-2 induced a sustained increase in concentration of intracellular free calcium. Western blot revealed that MLL-2 induced apoptosis in MCF-7 cells was associated with typical apoptosis proteins in the mitochondrial pathway. In addition, the caspase-3 activity in MCF-7 cells treated with MLL-2 for 48 hours was significantly increased compared to controls (407.4 ± 3.0 vs. 1749.2 ± 6.0, P <0.01). Since MLL-2 induced apoptosis in MCF-7cells the mitochondrial pathway may be the main pathway of antitumor activity.

Purification and characterization of a new D-galactose-specific lectin from the housefly, Musca domestica, and its antiproliferative effect on human K562 and MCF-7 tumor cells

In the present work, a D-galactose-specific lectin with novel N-terminal sequence was purified from Musca domestica L. (Diptera: Muscidae) pupae. The purification was performed using affinity chromatography, ultra-filtration, and HPLC. The haemagglutinating activity of M. domestica lectin was specifically inhibited by D-galactose. The haemagglutinating activity of this lectin was stable at temperatures up to 65 degrees C and in pH ranging from 4 to 8. Salts including FeCl(3) and MnCl(2) inhibited the haemagglutinating process, whereas NaCl, KCl, CaCl(2), MgCl(2), ZnCl(2), and AlCl(3) did not. By SDS-PAGE, purified M. domestica pupae lectin yielded a single band with a molecular weight of 40 kDa, with or without reduction of beta-mercaptoethanol, and it could be stained with Alcian Blue 8 GX. The morphology of purified lectin was observed by atomic force microscopy, which indicated that M. domestica lectin was an 8.27 nm high, globular shaped glycoprotein with a 1.41 nm high polysaccharide chain. In addition, antiproliferative activity of this lectin against tumor cells K562 and MCF-7 was determined with a colorimetric assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, which showed that the antiproliferative process was time- and dose-dependent with an IC(50) of 5.7 and 6.7 at 24 h, 5.5 and 6.4 at 36 h, 5.2 and 6.5 microM at 48 h, respectively.

Regeneration of foreign genes co-transformed plants of Medicago sativa L by Agrobacterium rhizogenes

Gene encoding sulphur amino acid-rich protein (HNP) and rol genes were transferred into Medicago sativa L (alfalfa) mediated by Agrobacterium tumafeciens. Regeneration of transgenic plants was induced successfully from hairy root tissue of cotyledon in alfalfa. Cotyledon tissues were an ideally transformed recipient. There was a negative correlation between age of hairy roots and embryogenesis frequency in alfalfa. Production of co-transformed plants with greater yield and super quality was important for development of new alfalfa varieties.

New mutations in the transglutaminase 1 gene in three families with lamellar ichthyosis

BACKGROUND

Autosomal recessive lamellar ichthyosis (LI) is a severe skin disorder characterized by generalized hyperkeratosis. Gene mutation in transglutaminase 1 (TGM1), which mediates cross-links in the formation of the cell envelope during terminal differentiation of epidermis, has been identified as a cause of LI.

OBJECTIVES

To determine mutations of TGM1 gene in three Chinese families with LI.

METHODS

The TGM1 gene was sequenced to identify disease-causing mutations in the three families with LI. One of the results was confirmed by using reverse transcriptase PCR and in situ hybridization. An in situ transglutaminase (TGase) 1 assay was performed to estimate TGase 1 activity in the patients' skin.

RESULTS

Four novel mutations of keratinocyte TGase1 (Q203X, D254N, R687H and IVS4 + 1G-->T) were found in the three families. No TGase 1 mRNA was detected in patient skin using RT-PCR and in situ hybridization, and the in situ TGase assay showed that there was no or decreased TGase 1 activity in patient skin.

CONCLUSIONS

Our findings suggest that four novel mutations in TGM1 gene result in decrease or absence of TGase activity in the skin and, as a consequence, cause the phenotype of LI.

BNIP3L (Nix) expression in colon cancer

e15097

Background: Microenvironmental adaptation to hypoxic conditions is critical for a cell to survive in a growing solid tumor. BNIP3L (Nix) mediates apoptosis during hypoxia in cancer cell lines, and Nix knockdown promotes tumor growth in-vivo through decreased apoptosis and increased proliferation, suggesting a means by which cells can adapt. Little is known specifically about Nix expression and its importance in human colon cancer. To gain insight into expression of this gene in colon tumors, the present study analyzed mRNA microarray data from 227 colon tumors and 22 normal colon tissue samples and queried differential expression of Nix. These results were compared to the protein levels present in human colon tumors. Methods: mRNA expression of 227 human colon tumors (made available by the Expression Project for Oncology (expO)) and 22 normal colon samples (retrieved from the Gene Expression Omnibus (GEO)) was analyzed. These samples were hybridized to the Affymetrix GeneChip Human Genome U133 Plus 2.0 Array, assaying 17,726 NCBI Entrez genes. Immunohistochemistry was performed on human tissue microarray CO701 (US Biomax, Inc.) containing 62 tumor samples. Results: Nix mRNA levels were shown to increase from normal to cancer (log-fold change of 0.961, Benjamini-Hochberg FDR adjusted p < 0.001). IHC demonstrated variable levels of Nix present in colon tumors: 38/62 (61.3%) of tumors stained positive for Nix while 24/62 (38.7%) were negative. Conclusions: We have shown that mRNA levels of Nix are upregulated in the transition from normal colon tissue to cancer but that protein levels in tumors demonstrate variable expression. This suggests that silencing of Nix occurs at various stages of tumorigenic progression and results in isolated populations of cells within a growing tumor that are uniquely resistant to apoptosis. Better understanding of Nix in the context of a growing colon tumor is needed and could lead to development of more successful therapeutics.

No significant financial relationships to disclose.

False-positive diagnosis of breast cancer by diffused optical tomography with ultrasound

e22085

Background: Breast cancer is one of the most common cancer in women. Early detection, early diagnosis and early treatment play key role in fighting against breast cancer. OPTIMUS system is a system of diffused optical tomography with ultrasound. It provides dual modality images for early diagnosis of breast cancer. The aim of this study was to evaluate the OPTIMUS system on diagnosis of breast disease. Methods: OPTIMUS system was applied to 160 breast tumor patients. All patients had received surgical treatment and had definite pathological diagnosis. OPTIMUS system was evaluated as diagnostic tool of breast tumor in this study. Results: There were 42 cases diagnosed as benign breast disease and 118 cases diagnosed as breast cancer by OPTIMUS system. Pathology confirmed 60 cases of benign disease and 100 cases of breast cancer. False positive rate of breast cancer was 30% (18/60). False negative rate of breast cancer was 0% (0/100). The pathology of false positive cases was mild and severe papillomatosis (6/18), non-typical hyperplasia (4/18), chronic inflammation (3/18), fibroadenoma (3/18) and fat necrosis (2/18). Papillomatosis and non-typical hyperplasia are precancerous lesions and often difficult for clinical diagnosis. In this study the false positive diagnostic rate of mammography and ultrasonography is 13% and 11.1% respectively. Conclusions: OPTIMUS system is a non- invasive and highly effective diagnostic tool for breast disease. Its sensitivity is reached to 100% and specificity is about 70% on the diagnosis of breast cancer. OPTIMUS system could be used as assistant diagnostic tool for breast tumor.

No significant financial relationships to disclose.

Molecular characterisation of outbreak-related strains of vancomycin-resistant Enterococcus faecium from an intensive care unit in Beijing, China

We investigated an outbreak of vancomycin-resistant Enterococcus faecium affecting 14 patients in a 20-bed intensive care unit (ICU) between September 2006 and August 2007 (incidence: 3.56 cases per 1000 ICU patient days). Eighteen isolates of vanA type E. faecium were analysed by pulsed field gel electrophoresis, which showed 14 types overall. Multilocus sequence typing (MLST) identified eight different sequence types (STs) (ST78, ST117, ST203, ST316, ST362, ST363, ST364 and ST365), including four new types (ST362, ST363, ST364 and ST365) and 17 strains belonged to clonal complexes CC17. Sixteen of these carried the esp gene. Eighteen Tn1546-like elements encoding vanA-type VRE were classified into three types (types I to III) and all of them contained both IS1216V and IS1542 insertions. Vancomycin resistance of 14 vanA type E. faecium isolates was transferred at a frequency of 1.3 x 10(-6) to 6.4 x 10(-5) between E. faecium strains during filter mating. Our findings indicate that conjugative dissemination of Tn1546-like elements among CC17 E. faecium occurred during the outbreak in this ICU.

Screening and characterization of monoclonal antibodies to the surface antigens of Listeria monocytogenes serotype 4b

AIMS

This study aims to develop and characterize monoclonal antibodies (Mabs) with high specificity and affinity for surface antigens of an epidemiologically important serotype 4b of Listeria monocytogenes.

METHODS AND RESULTS

Hybridoma clones were derived from B lymphocytes of mice immunized with L. monocytogenes serotype 4b and screened against this strain by an enzyme-linked immunosorbent assay. Twenty-nine clones secreting Mabs reactive with formalin-killed bacteria were obtained; 15, 8, 5 and 1 Mabs were immunoglobulin subclasses IgG2a, IgG2b, IgM and IgG1, respectively. Immunofluorescence or immunogold labelling demonstrated all except five IgM and one IgG2a Mabs bound to the surface of a live L. monocytogenes serotype 4b. The majority of the 23 surface-binding Mabs recognized linear epitopes on a 77-kDa protein. These surface-binding Mabs exhibited little or no cross-reactivity with non-4b serotypes (1/2a, 1/2b, 3a, etc.) of L. monocytogenes, five other Listeria species, Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium.

CONCLUSIONS

The Mabs recognizing a 77-kDa surface protein are novel antibodies with specificity and affinity for L. monocytogenes serotype 4b.

SIGNIFICANCE AND IMPACT OF THE STUDY

These anti-77 kDa surface protein Mabs may be explored as reagents for the development of Mabs-based diagnostic immunoassays for L. monocytogenes serotype 4b strains.

212 EFFECTS OF VASCULAR ENDOTHELIAL GROWTH FACTOR ON THE EARLY DEVELOPMENT AND POLYSPERMY RATE OF OVINE EMBRYOS PRODUCED IN VITRO

To investigate the effect of vascular endothelial growth factor (VEGF) on the early development and polyspermy rate of ovine embryos in vitro, 2 experiments were conducted with human recombinant VEGF165 supplemented to the media during maturation, fertilization, and culture in vitro, respectively. Ovaries were collected from ewes at a local slaughterhouse. All oocytes surrounded by a multilayer of cumulus cells were collected and rinsed 3 times in maturation medium (control medium and treatment medium, respectively). A total of 100 oocytes in each group were cultured in 4-well plates (Nunc) containing 800 μL of maturation medium at 38.5°C in an atmosphere of 5% CO2 with saturated humidity. Four replicates of each experiment were conducted. Statistical analyses were conducted by ANOVA with SPSS 12.0 software (SPSS Inc., Chicago, IL, USA). Data are expressed as means, and P < 0.05 was considered significant. In Experiment 1, to investigate the effect of VEGF on the early development of ovine embryos in vitro, VEGF was used at 5 ng mL–1 (treatment group A) and 10 ng mL–1 (treatment group B) in maturation medium (TCM-199 + BSA), HSOF fertilization medium, and SOF culture medium. The results showed that the maturation rate was increased significantly (P < 0.01), from 75.76% in the control treatment to 83.98 and 80.23% in treatment group A and treatment group B, respectively. The cleavage rate was increased from 75.85% in the control group to 79.39% in treatment group A (P > 0.05). The development rates of morulae (45.03%) and blastocysts (23.54%) in treatment group A were significantly higher (P < 0.01) than those in the control group (38.94 and 18.09%, respectively). In addition, the development rates of blastocysts in treatment group B (21.05%) were lower than those in treatment group A (P > 0.05) and higher than those in the control group (P > 0.05). In Experiment 2, to investigate the effect of VEGF on the polyspermy rate of ovine embryos in vitro, 5 ng mL–1 of VEGF was used in TCM-199 + BSA maturation medium in this experiment. The results showed that the fertilization rate after 18 h of IVF was increased significantly (P < 0.01), from 75.75% in the control group to 83.86% in the treatment group, and that the polyspermy rate was decreased significantly (P < 0.01), from 12.64% in the control group to 7.68% in the treatment group. These results indicate that VEGF significantly improved the maturation and fertilization rates of ovine oocytes and, consequently, the rate of embryo development in vitro, especially when the medium was supplemented with 5 ng mL–1 of VEGF. The VEGF obviously decreased the polyspermy rate and bated the phenomenon of polyspermy in the process of ovine oocyte IVF. The present study was supported by the National Natural Science Foundation of China (No. 30371035).

Therapeutic effects on experimental metastatic tumor-bearing mice by vaccination with GM-CSF gene-modified and tumor antigen-pulsed macrophages

Macrophages, with potent cytotoxic and antigen-presenting activities, can be used in cancer treatment. The biological characteristics and antitumor effect of GM-CSF gene-modified and tumor antigen-pulsed macrophages were investigated. The high levels of GM-CSF could be detected in the supernatants of macrophages after gene transfer. The cytotoxicity and the expression of MHC class II molecules of the gene-modified macrophages increased significantly and the antigen-presenting ability was enhanced. The gene-modified macrophages were then pulsed with tumor antigen and used to treat the experimental pulmonary metastastic mice. The number of pulmonary metastases was reduced significantly and the cytotoxicity of the CTL induced from the splenocytes of the tumor-bearing mice also increased. The results demonstrated that adenovirus-mediated GM-CSF gene transfer can activate macrophages to some extent and GM-CSF gene-modified, antigen-pulsed macrophages may be a new type of effective effector cells in the immunogene therapy of cancer.

Assessing dietary patterns in Barbados highlights the need for nutritional intervention to reduce risk of chronic disease

BACKGROUND

The dietary habits of the Caribbean have been changing to include more fast foods and a less nutrient dense diet. The aims of this study are to examine dietary patterns in Barbados and highlight foods for a nutritional intervention.

METHODS

Four-day food diaries collected from control participants in the population-based, case-control Barbados National Cancer Study (BNCS).

RESULTS

Forty-nine adult participants (91% response) completed the diaries providing 191 days of dietary data. Total energy intake was almost identical to data collected 5-years earlier in the Barbados Food Consumption and Anthropometric Survey 2000, but the percent energy derived from fat was from 2.1% to 5.2% higher. Sugar intake exceeded the Caribbean recommendation almost four-fold, while intakes of calcium, iron (women only), zinc and dietary fibre were below recommendations. Fish and chicken dishes were the two largest sources of energy and fat. Sweetened drinks and juices provided over 40% of total sugar intake.

CONCLUSIONS

These data provide existing dietary patterns and strongly justify a nutritional intervention program to reduce dietary risk factors for chronic disease. The intervention could focus on the specific foods highlighted, both regarding frequency and amount of consumption. Effectiveness can be evaluated pre- and post-intervention using our Food Frequency Questionnaire developed for BNCS.

Leukocytes of exceptionally old persons display ultra-short telomeres

With a view to understanding the association between leukocyte telomere length and the human lifespan, we performed genome-wide telomere length analyses by the terminal restriction fragment length (TRFL) and single molecule telomere length analysis (STELA) of the X and Y chromosomes in leukocytes of exceptionally old (aged 90–104 yr) and younger (aged 23–74 yr) individuals. We found that the mean TRFL of 82 exceptionally old individuals was within a range projected by age-dependent TRFL attrition of 99 younger individuals. However, compared with the younger individuals, exceptionally old persons exhibited peaking of the TRFL distribution with overrepresentation of ultra-short telomeres. These findings were confirmed by the STELA. Women had longer mean TRFL than men (6.10 vs. 5.86 kb), and exceptionally old women exhibited fewer ultra-short telomeres than exceptionally old men. Our results have implications for gerontological studies of the limitation of lifespan in humans.

Vacuum-ultraviolet Gabor holography with synchrotron radiation

We present the realization of high-resolution holographic microscopy using the original Gabor geometry and imaging with radiation in the vacuum-ultraviolet (VUV) spectral region. Synchrotron VUV radiation with a wavelength of 13.8 nm was focused on a small pinhole generating a highly divergent light cone suitable for digital in-line holography. Objects of different thickness and materials have been used to test the imaging properties of holographic microscopy in the VUV wavelength range. The effective numerical aperture was limited by the illuminated area of the detector, yielding a theoretical resolution below 1 microm and an experimental one of approximately 1 microm.

Magnesium-rich minerals in sediment and suspended particulates of South Florida water bodies: implications for turbidity

Fine sediments in shallow water bodies such as Lake Okeechobee are prone to resuspension. Predominantly inorganic "mud" sediment that covers approximately 670 km2 of the lake has been recognized as a persistent source of turbidity. The objective of this study was to determine if mineral components of sediments in Lake Okeechobee and water conveyances of the northern Everglades also occur as suspended sediment and hence constitute a potential abiotic contributor to turbidity. Sediment samples were collected from nine stations within the lake and eight locations north of Water Conservation Area 2A in the Everglades. Water samples were also collected at selected locations. The silt and clay mineralogy of sediment and suspended particles was determined using X-ray diffraction, thermogravimetry, scanning-electron microscopy, energy-dispersive X-ray elemental microanalysis, and high-resolution transmission-electron microscopy. Clay fractions of the lake sediment contained the Mg silicate minerals sepiolite and palygorskite, along with smectite, dolomite, calcite, and kaolinite. Sediment silt fractions were dominated by carbonates and/or quartz, with smaller amounts of Ca phosphates and sepiolite. Mineralogy of the mud sediment was similar to that reported for geologic phosphate deposits. This suggests that the mud sediment might have accumulated by stream transport of minerals from these deposits. Suspended solids and mud-sediment mineralogy were similar, except that smectite was more abundant in suspended solids. Everglade samples also contained Mg-rich minerals. The small size, low density, and fibrous or platy nature of the prevalent mud sediment minerals make them an abiotic, hydrodynamically sensitive source of persistent turbidity in a shallow lake. Mitigation efforts focused exclusively on P-induced biogeochemical processes do not address the origin or effects of these minerals. Ecological management issues such as turbidity control, P retention, geologic P input, and suitability of dredging are related to mud-sediment properties and provenance.

Quantitative monitoring by polymerase colony assay of known mutations resistant to ABL kinase inhibitors

Resistance to molecularly targeted chemotherapy, and the development of novel agents that are active against resistant forms of target proteins create the need for a sensitive and quantitative assay to monitor drug-resistant mutations in patients to guide treatment and assess response. Here, we describe an application of the polymerase colony (polony) method to identify and quantify known point mutations in the BCR-ABL oncogene in patients with chronic myelogenous leukemia who evolve resistance to ABL kinase inhibitors. The assay can detect mutations with a sensitivity of 10(-4), quantify the burden of drug-resistant cells, and simultaneously monitor the dynamics of several coexisting mutations. As a proof of concept, we analysed blood samples from three patients undergoing therapy with ABL kinase inhibitors and found that the patients' response to therapy correlated with our molecular monitoring. We were also able to detect mutations emerging in patients long before clinical relapse. Therefore, the polony assay could be applied to a larger patient sample to assess the utility of early mutation detection in patient-specific treatment decisions. Finally, this methodology could be a valuable research tool to shed light on the natural behavior of mutations pre-existing kinase inhibitors therapy and either disappearing over time or slowly taking over.

Down regulation of gastric and intestinal phenotypic expression in Epstein-Barr virus-associated stomach cancers

AIMS

We have previously demonstrated the importance of gastric and intestinal phenotypic expression for stomach carcinogenesis. In this study, we focused on Epstein-Barr virus (EBV)-associated stomach cancers, with special attention to Cdx2.

METHODS AND RESULTS

We evaluated the expression of gastric and intestinal phenotypic markers by immunohistochemistry in 35 EBV-positive [EBV (+)] and 75 EBV-negative [EBV (-)] stomach cancers in Colombia. The lesions were divided phenotypically into gastric (G), gastric-and-intestinal mixed (GI), intestinal (I), and null (N) phenotypes. In the EBV (+) cases, the lesions were divided phenotypically into 9 G (25.7%), 1 GI (2.9%), 3 I (8.6%), and 22 N (62.9%) types. Similarly, the EBV (-) lesions were also classified phenotypically as 15 G (20.0%), 19 GI (25.3%), 24 I (32.0%), and 17 N (22.7%) types. The proportion of N type EBV (+) lesions was higher than for their EBV (-) counterparts (P<0.0001). The expression of Cdx2 and MUC2 was also found to be significantly lower in EBV (+) than in EBV (-) stomach cancers (P=0.0001; P<0.0001). Cdx2 expression in the intestinal metaplastic glands present in non-neoplastic mucosa surrounding EBV (+) lesions was also significantly lower than in EBV (-) tumors (P=0.016) despite no evidence of EBV infection.

CONCLUSIONS

EBV (+) stomach cancers are characterized by low expression of intestinal phenotype markers, including Cdx2, and only occasional gastric phenotypic expression.

Pin1 is required for the Ser727 phosphorylation-dependent Stat3 activity

Signal transducer and activator of transcription 3 (Stat3) belongs to a family of latent cytoplasmic transcription factors important for cytokine signaling. Stat3 is constitutively activated in various tumors, and activated Stat3 itself also acts as an oncogene. Transcriptional activity of Stat3 is controlled by Tyr-phosphorylation, followed by dimerization and nuclear translocation. However, phosphorylation on Ser727 is indispensable for its maximal transcriptional activity with unclear mechanism. Here, we report that peptidyl-prolyl cis/trans isomerase 1 (Pin1), which specifically recognizes the pSer/Thr-Pro motifs on its target proteins, interacts with Stat3 upon cytokine/growth factor stimulation. Overexpression of Pin1 promotes Stat3 transcriptional activity and target gene expression, as well as recruitment of transcription coactivator, p300. These effects, however, were compromised in the Pin1-deficient cells, and were totally dependent on the Ser727 phosphorylation site. Finally, we showed that Pin1 enhances Stat3-mediated epithelial-mesenchymal transition in breast cancer cells induced by oncostatin M. Our data reveal a novel, Ser727 phosphorylation-dependent, post-translational regulation mechanism for Stat3.

Pin1 is required for the Ser727 phosphorylation-dependent Stat3 activity

Signal transducer and activator of transcription 3 (Stat3) belongs to a family of latent cytoplasmic transcription factors important for cytokine signaling. Stat3 is constitutively activated in various tumors, and activated Stat3 itself also acts as an oncogene. Transcriptional activity of Stat3 is controlled by Tyr-phosphorylation, followed by dimerization and nuclear translocation. However, phosphorylation on Ser727 is indispensable for its maximal transcriptional activity with unclear mechanism. Here, we report that peptidyl-prolyl cis/trans isomerase 1 (Pin1), which specifically recognizes the pSer/Thr-Pro motifs on its target proteins, interacts with Stat3 upon cytokine/growth factor stimulation. Overexpression of Pin1 promotes Stat3 transcriptional activity and target gene expression, as well as recruitment of transcription coactivator, p300. These effects, however, were compromised in the Pin1-deficient cells, and were totally dependent on the Ser727 phosphorylation site. Finally, we showed that Pin1 enhances Stat3-mediated epithelial-mesenchymal transition in breast cancer cells induced by oncostatin M. Our data reveal a novel, Ser727 phosphorylation-dependent, post-translational regulation mechanism for Stat3.

Mutations and nuclear accumulation of beta-catenin correlate with intestinal phenotypic expression in human gastric cancer

AIMS

Abnormal localization of beta-catenin is frequently observed in human gastric cancers. The aim of the present study was to evaluate relationships among gastrointestinal differentiation phenotypes, beta-catenin localization and mutations of Wnt signalling genes.

METHODS AND RESULTS

Seventy-seven regions in 39 gastric adenocarcinomas were classified according to beta-catenin localization and gastric and intestinal phenotypes. Cases with membranous beta-catenin localization showed a gradual decrease from gastric (G) (55% = 6/11) and gastric-and-intestinal-mixed (GI) (17% = 5/29) to intestinal (I) (0% = 0/21) phenotypes, while those with nuclear localization showed a concomitant increase: 18% (2/11), 41% (12/29), 95% (20/21) and 63% (10/16) for G, GI, I and null type (N), respectively (P < 0.001, membranous versus nuclear localization in G, GI through I). Mutations in exon 3 of the beta-catenin gene were found in G (50% = 1/2), GI (67% = 8/12), I (45% = 9/20) and N (0% = 0/10) regions with nuclear beta-catenin localization (GI versus N, P < 0.01; I versus N, P < 0.05). Adenomatous polyposis coli (APC) gene mutations were demonstrated only in GI, I and N types, irrespective of beta-catenin localization. Molecular analysis of these genes revealed 10 tumours to be heterogeneous out of 16 informative cases (62.5%).

CONCLUSION

Intestinal phenotypic expression is accompanied by a shift from membranous to cytoplasmic/nuclear accumulation of beta-catenin. In contrast, N-type regions may progress along a different pathway.

Approaching actinide(+III) hydration from first principles

A systematic computational approach to An(III) hydration on a density-functional level of theory, using quasi-relativistic 5f-in-core pseudopotentials and valence-only basis sets for the An(III) subsystems, is presented. Molecular structures, binding energies, hydration energies, and Gibbs free energies of hydration have been calculated for [An(III)(OH(2))(h)](3+) (h = 7, 8, 9) and [An(III)(OH(2))(h-1) * OH(2)](3+) (h = 8, 9), using large (7s6p5d2f1g)/[6s5p4d2f1g] An(III) and cc-pVQZ O and H basis sets within the COSMO implicit solvation model. An(III) preferred primary hydration numbers are found to be 8 for all An(III) at the gradient-corrected density-functional level of theory. Second-order Møller-Plesset perturbation theory predicts preferred primary hydration numbers of 9 and 8 for Ac(III)-Md(III) and No(III)-Lr(III), respectively.