Retrospective multicenter study of a clinicopathologic analysis of pseudomyxoma peritonei associated with ovarian tumors (KGOG 3005)

The purpose of this study is to assess clinicopathologic features of pseudomyxoma peritonei (PMP) that has ovarian pathology and its relationship with the prognosis. From 1995 to 2004, the clinical records and follow-up data of 35 patients with PMP, which had primarily originated from the ovary, were collected from 11 institutes of gynecologic oncology in Korea and retrospectively analyzed. All patients had ovarian lesion histologically confirmed with PMP. The mean age at diagnosis was 53.7 years (range: 16-82 years). There were 25 (71.4%) patients with disseminated peritoneal adenomucinosis, 5 (14.3%) with peritoneal mucinous carcinomatosis with intermediate group, and 5 (14.3%) with peritoneal mucinous carcinomatosis. The clinical stages at diagnosis were IA in 2 patients, IIIB in 4, IIIC in 23, IV in 1, and unknown in 5. In preoperative tumor markers, the positive rates were 72% (CA125), 47.4% (CA19-9), and 84.6% (CEA). Thirty-four patients underwent surgical staging or cytoreduction, and then 27 patients (77%) received adjuvant chemotherapy that was given to patients in a nonuniform fashion. The 5-year survival for 35 patients was 87%. Survival rate was significantly lower in patients >50 years of age (P = 0.002). Our data showed that age of the patient is the only significant prognostic factor in PMP that has ovarian lesion.

Proteomic profiling of endothelial cells in human lung cancer

Genomic and proteomic analysis of normal and diseased tissues have yielded an abundance of molecular information for diagnostic and potential therapeutic targets. Changing the target of analysis from poorly accessible cells within tissues to easily accessible vascular endothelium has theoretical advantages in tissue-specific targeting. In this study, we sought to map a large-scale proteome of microvascular endothelium in human non-small cell lung cancer (NSCLC) and normal lung tissues, and identify lung cancer-related endothelial cell (EC)-selective proteins. Endothelial cells were isolated within NSCLC tissues and adjacent-normal lung tissue of lung cancer patients by using CD31-immunomagnetic beads. The complex proteins from the ECs were separated by one-dimensional gel electrophoresis, and the proteins in each gel band were digested by trypsin. Peptides were separated by online reverse-phase liquid-chromatography and analyzed by electrospray ionization (ESI) ion trap tandem mass spectrometry. Approximately 600-1000 proteins were identified in each individual sample. Five patient cases of paired individual data, extracted from the protein identification data sets of both normal- and cancer-derived ECs, were analyzed by subtractive proteomics. An average of 300 proteins was specifically identified from each lung cancer-derived EC isolate, compared to normal lung-derived ECs. With the use of several comparative analyses, we identified among those 300 proteins, 16 common candidate proteins that were detected in at least 3 of 5 cases specific to lung cancer-derived ECs. Proteins selectively identified in cancer-derived ECs, including coatomer protein complex, subunit gamma (COPG), and peroxiredoxin 4 (PRDX4), were validated by Western blot analysis. In an additional experiment in which 16 cancer samples were analyzed by immunohistochemistry, PRDX4, thymopoietin (TMPO), and COPG were confirmed to be abundantly expressed in lung cancer-derived ECs and in cancerous lung cells. Further ongoing analysis of these 16 candidate proteins will determine their potential applicability to NSCLC-specific diagnosis and therapeutics.

Direct observation of oxygen superstructures in manganites

We report the observation of superstructures associated with the oxygen 2p states in two prototypical manganites using x-ray diffraction at the oxygen K edge. In the stripe order system Bi0.31Ca0.69MnO3, hole-doped O states are orbitally ordered, at the same propagation vector as the Mn orbital ordering, but no oxygen charge stripes are found at this periodicity. In La7/8Sr1/8MnO3, we observe a 2p charge ordering described by alternating hole-poor and hole-rich MnO planes that is consistent with some of the recent predictions.

Novel cationic solid lipid nanoparticles enhanced p53 gene transfer to lung cancer cells

Mutations in the p53 tumor suppressor gene are the most common molecular genetic abnormalities to be described in lung cancer. However, there have been few reports of nonviral vector-mediated p53 gene delivery in lung cancer. A new formulation of cationic solid lipid nanoparticles (SLNs) for gene delivery was produced by the melt homogenization method with slight modification, and the SLNs were formulated by mixing tricaprin (TC) as a core, 3beta[N-(N', N'-dimethylaminoethane) carbamoyl] cholesterol (DC-Chol), dioleoylphosphatidylethanolamine (DOPE) and Tween 80 in various ratios. Plasmid DNA (pp53-EGFP)/SLNs complexes were transfected into human non-small cell lung cancer cells (H1299 cells) and transfection efficiency was determined by FACS analysis. The gene expression was determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. The cellular growth inhibition and apoptosis of treated cells with pp53-EGFP/SLNs complexes were assessed by trypan blue exclusion assay and annexin V staining, respectively. In vivo biodistribution of plasmid DNA was investigated by PCR and RT-PCR. The transfection efficiency of SLN1 (TC:DC-Chol:DOPE:Tween 80=0.3:0.3:0.3:1), which showed the highest transfection efficiency among the SLN formulations, was higher than that of commercially available Lipofectin. The SLNs-mediated transfection of the p53 gene resulted in efficient high levels of wild-type p53 mRNA and protein expression levels in H1299 cells. The efficient reestablishment of wild-type p53 function in lung cancer cells restored the apoptotic pathway. Taken together, our results reveal that cationic SLN-mediated p53 gene delivery may have potential for clinical application as a nonviral vector-mediated lung cancer therapy due to its effective induction of apoptosis and tumor growth inhibition.

The suppressive effect of myeloid Elf-1-like factor (MEF) in osteogenic differentiation

Myeloid Elf-1 like factor (MEF) is a member of the Ets transcription factor family. Ets family proteins control the expression of genes that are critical for biological processes such as proliferation, differentiation, and cell death. Some of Ets factors are also known to regulate bone development. In this study, we investigated the role of MEF in osteoblast differentiation. MEF expression was highest early in the differentiation of MC3T3-E1 osteoblasts and was reduced by treatment with BMP-2. The expression of MEF suppressed the alkaline phosphatase activity and expression induced by BMP-2 stimulation and mediated by Runx2. The expression of MEF also reduces osteocalcin mRNA levels, and mineralization in MC3T3-E1 cells. We found that the MEF-mediated suppression of osteogenic differentiation was critically related to Runx2 regulation. The MEF and Runx2 proteins physically interact to form a complex, and this interaction interferes with Runx2 binding to the cis-acting element OSE2 derived from the osteocalcin promoter. Co-transfection of MEF inhibited the 6xOSE2-luciferase reporter activity induced by Runx2. In addition, MEF stimulated the transcription of a negative mediator Msx2, and a transcriptional repressor, Mab21L1, and suppressed the transcription of a positive mediator, Dlx5 in osteoblast differentiation. MEF overexpression stimulated C2C12 cell proliferation. Together, our findings suggest that MEF promotes cell proliferation and functions as a negative regulator of osteogenic differentiation by directly interacting with Runx2 and suppressing its transcriptional activity.

Macular degeneration in an arc welder

A male welder who had been working in an industrial machine plant for more than 20 years experienced acute intense pain in his left eye with continuous lacrimation while performing arc welding in 1997. Later in 1997, at the age of 39 yr, macular edema was found in his left eye. He was diagnosed with macular degeneration (MD) of the left eye in 2002, and with right eye MD in 2004. Radiation in the visible and near infrared (IR) spectra penetrates the eye and is absorbed by the retina, possibly causing thermal or photochemical damage. Such retinal damage may be permanent and, therefore, sight-threatening. The young age and history of an acute painful eye injury are not consistent with age related macular degeneration (AMD) but rather is likely maculopathy caused by welding arc exposure.

Glucocorticoid receptor represses the Dex-mediated induction of human androgen response element-linked Luc activity

A human androgen response element (hARE), identified within intron 8 of the human sterol regulatory element-binding protein cleavage-activating protein, interacts with both glucocorticoid receptor (GR) and androgen receptors (AR). The aim of this study was to test the hypothesis that human GR (hGR) might modulate the expression of a hARE-linked reporter gene by dexamethasone (Dex). The hypothesis was tested by: a) co-transfecting HepG2 cells with a hGR and a luciferase (Luc)-reporter gene for performing in vitro investigations and b) by their co-injection into the tail vein of mice for in vivo investigation. In vitro co-transfected cells and the in vivo co-injected mice were then treated with Dex. Our results have led us to concluded that both transfection and injection of the hGR leads to a repression in the Dex-mediated induction of hARE-linked Luc activity both in vitro and in vivo settings. These findings suggest that this assay system allows screening of drug candidates affecting to a signal transduction pathway of the GR and AR and may help in the future discovery and analysis of novel and selection of GR and AR agonists.

Technical note: A model to estimate individual feed intake of swine in group feeding

In most animal growth experiments, groups of animals are housed within a pen. Occasionally, an individual animal shows a very different growth rate than its pen mates or dies during the experiment. When this happens, if pen feed intake (PFI) cannot be reestimated for the calculation of ADFI and feed efficiency, an observation will be lost from the data set. Therefore, we propose a model to estimate individual feed intake (IFI) of pigs in group feeding, with subsequent validation of the model using group feeding simulation studies. In the proposed model, the feed intake (FI) of each affected pen is partitioned into FI for maintenance (FI(m)) and FI for growth (FI(g)) for each animal within that pen. First, individual pig FI(m) for the period is calculated using the 1998 National Research Council estimation of ME for maintenance. Then, FI(m) for all pigs in the pen is summed. The difference between the summed FI(m) and the total PFI is that which supported growth in the pen. Next, FI(g) is calculated by apportioning the remaining feed equally to each unit of gain within the pen. Finally, the estimated IFI for the pig being removed from the pen is the sum of FI(m) and FI(g) for that pig; this FI estimate is subtracted from the original PFI to leave the new PFI for the remaining pigs. The validity of the estimated IFI is dependent on the accuracy of the maintenance energy equation and the energy analysis of the feedstuffs. In simulation studies, we compared the accuracy of the proposed method with 2 other methods. In simulation study 1, the proposed model showed better accuracy than at least one of the other methods during all tested periods (P < 0.001). In simulation study 2, the greater accuracy of the proposed method compared with 2 other methods was demonstrated again. Because calculation of IFI is relatively cumbersome, we developed a feed intake correction spreadsheet (FICS), an Excel spreadsheet containing macros for FI correction. All of the calculation procedures in the proposed model are included within the feed intake correction spreadsheet. The Excel file and instructions are being made available via a Web site.

Smad4 signalling in T cells is required for suppression of gastrointestinal cancer

SMAD4 (MAD homologue 4 (Drosophila)), also known as DPC4 (deleted in pancreatic cancer), is a tumour suppressor gene that encodes a central mediator of transforming growth factor-beta signalling. Germline mutations in SMAD4 are found in over 50% of patients with familial juvenile polyposis, an autosomal dominant disorder characterized by predisposition to hamartomatous polyps and gastrointestinal cancer. Dense inflammatory cell infiltrates underlay grossly normal appearing, non-polypoid colonic and gastric mucosa of patients with familial juvenile polyposis. This prominent stromal component suggests that loss of SMAD4-dependent signalling in cells within the epithelial microenvironment has an important role in the evolution of intestinal tumorigenesis in this syndrome. Here we show that selective loss of Smad4-dependent signalling in T cells leads to spontaneous epithelial cancers throughout the gastrointestinal tract in mice, whereas epithelial-specific deletion of the Smad4 gene does not. Tumours arising within the colon, rectum, duodenum, stomach and oral cavity are stroma-rich with dense plasma cell infiltrates. Smad4(-/-) T cells produce abundant T(H)2-type cytokines including interleukin (IL)-5, IL-6 and IL-13, known mediators of plasma cell and stromal expansion. The results support the concept that cancer, as an outcome, reflects the loss of the normal communication between the cellular constituents of a given organ, and indicate that Smad4-deficient T cells ultimately send the wrong message to their stromal and epithelial neighbours.

Characterization of an O-methyltransferase from soybean

O-methyltransferases (OMTs) catalyze the transfer of a methyl group from S-adenosine-L-methionine to a hydroxyl group of an acceptor molecule to form methyl ether derivatives and can modify the basic backbone of a secondary metabolite. A new O-methyltransferase, SOMT-9, was cloned from Glycine max and found to encode a protein whose molecular weight is 27-kDa. SOMT-9 was expressed as a GST-fusion protein in Escherichia coli and several compounds such as caffeic acid, esculetin, narigenin, kaempferol, quercetin, and luteolin were tested as putative substrates of SOMT-9. HPLC and NMR results showed that SOMT-9 transfers a methyl group to the 3'-OH group of substrates having ortho-hydroxyl groups. SOMT-9 showed the highest affinity for quercetin, suggesting that SOMT-9 uses a flavonoid as a substrate. Based on its molecular weight and substrate specificity, SOMT-9 belongs to a new class of OMT and is likely to be involved in the biosynthesis of isorhamnetin.

Runx2 phosphorylation induced by fibroblast growth factor-2/protein kinase C pathways

Runx2 is a key transcription factor in osteoblast differentiation, and its activity is regulated by fibroblast growth factors (FGFs). Craniosynostosis, characterized by premature suture closure, results from mutations that generate constitutively active FGF receptors (FGFRs). We previously showed that FGF/FGFR-activated protein kinase C (PKC) is involved in the expression and activity of Runx2. Activated PKCdelta physically interacts with Runx2 in FGF2-stimulated MC3T3-E1 preosteoblastic cells. Immunopurified Runx2 protein reacted with PKCdelta kinase, and a phosphorylated 1460-Da peptide fragment (amino acids 241-252, 1380-Da) derived from Runx2 was also detected in MS analysis. Computer analysis predicted that Ser247 in this Runx2 can be a possible phosphorylation site by PKCdelta. We also showed that Runx2 activity after FGF stimulation correlates with the presence of the Runx2 Ser247 residue. The S247A (Ser --> Ala) mutation confers decreased transcriptional activity on a Runx2-responsive promoter after FGF treatment.

Geographical difference in the prevalence of isolated systolic hypertension in middle-aged men and women in Korea: the Korean Health and Genome Study

To compare geographical difference in the prevalence of isolated systolic hypertension (ISH) in between urban (Ansan) and rural (Ansung) Korean adults aged 40-69 years, 4351 men and 4604 women enrolled in the Korean Health and Genome Study were analysed. Information was collected regarding gender, alcohol intake, smoking status, household income, occupation, and years of education by trained interviewers. Eligible subjects included untreated hypertensive and normotensive subjects. ISH was defined as a systolic blood pressure (SBP) > or = 140 mmHg and diastolic BP <90 mmHg. The overall age-adjusted prevalence of ISH was 4.1%. The prevalence of ISH in Ansung (5.7%) was higher than in Ansan (2.5%, P < 0.05). Also it increased with increments of age, from 1.0 to 12.8% in Ansung (P < 0.05) and from 0.3 to 13.0% in Ansan (P < 0.05). In those with body mass index (BMI) > or = 30.0 kg/m2 in Ansung, the prevalence of ISH in women was twice as much as in men. The prevalence of ISH in obese men and women with a waist-hip ratio > or =1.0 and > or = 0.85, respectively, was more than that of nonobese men and women in both areas. In Korea, because of industrialization, the age distribution was skewed and the Korean population in rural areas is more aged. ISH will become a truly major health problem in rural area, because ISH is related to age, BMI and waist-hip ratio. Therefore, the Korean government will be required to institute different policies in the hypertension management to target populations in rural and urban areas.

Equipment fault diagnosis system of sequencing batch reactors using rule-based fuzzy inference and on-line sensing data

The importance of a detection technique to prevent process deterioration is increasing. For the fast detection of this disturbance, a diagnostic algorithm was developed to determine types of equipment faults by using on-line ORP and DO profile in sequencing batch reactors (SBRs). To develop the rule base for fault diagnosis, the sensor profiles were obtained from a pilot-scale SBR when blower, influent pump and mixer were broken. The rules were generated based on the calculated error between an abnormal profile and a normal profile, e(ORP)(t) and e(DO)(t). To provide intermediate diagnostic results between "normal" and "fault", a fuzzy inference algorithm was incorporated to the rules. Fuzzified rules could present the diagnosis result "need to be checked". The diagnosis showed good performance in detecting and diagnosing various faults. The developed algorithm showed its applicability to detect faults and make possible fast action to correct them.

Efficacy of DL-methionine hydroxy analog free acid and DL-methionine as methionine sources for pigs1,2

Two experiments were conducted to evaluate the efficacy of dietary DL-methionine hydroxy analog-free acid (MHA-FA, 88%) compared with DL-methionine (DLM, 99%) as Met sources in pigs. In Exp. 1, a total of 245 crossbred pigs (initial BW of 6.4 kg [SD = 0.5]) were allotted to 7 treatments in 7 replicates for an experimental period of 28 d. The basal diet (BD) was formulated to contain 17.5% CP and 0.21% Met. Dietary treatments included 1) BD, 2) BD + 0.030% DLM, 3) BD + 0.060% DLM, 4) BD + 0.090% DLM, 5) BD + 0.034% MHA-FA, 6) BD + 0.068% MHA-FA, and 7) BD + 0.103% MHA-FA; the MHA-FA was supplemented on an equimolar basis to the DLM. Because of a nonlinear response, exponential regression analysis was used to evaluate the responses, and a comparison of the equations was then made to determine the relative effectiveness of the 2 Met sources. With increases in dietary Met, weight gain increased (P < 0.05). Compared with DLM on a product-to-product (wt/wt) basis, the relative effectiveness of MHA-FA was calculated to be 73% for increasing weight gain and 54% for decreasing the feed:gain. In Exp. 2, a total of 30 weanling barrows [initial BW of 16.8 kg (SD = 2.8)] were used in a metabolism study to evaluate the relative value of MHA-FA to DLM. The BD was formulated to contain 16.9% CP and 0.21% Met. Dietary treatments included 1) BD, 2) BD + 0.030% DLM, 3) BD + 0.060% DLM, 4) BD + 0.046% MHA-FA, and 5) BD + 0.092% MHA-FA; the MHA-FA levels were chosen based on a pre-experiment estimate of bioequivalence in an attempt to provide approximately equal pig responses. There was no difference in fecal N output among the treatments; however, urine N linearly decreased with increasing concentrations of both sources (P = 0.034 for DLM, and P = 0.007 for MHA-FA), which resulted in a linear increase in retained N for both DLM (P = 0.012) and MHA-FA (P = 0.005). In addition, N retention (% of intake) linearly increased with increasing level of DLM (P = 0.014) and MHA-FA (P = 0.007). Using a slope-ratio procedure for comparison of the responses from the 2 sources, the relative biological equivalence value of MHA-FA to DLM in this experiment was 64.2% based on percent N retention and 66.3% based on the grams of N retained per day. Based on the results from both experiments, these data indicated that the mean relative bioequivalence of MHA-FA to DLM was 64% on a product-to-product (wt/wt) basis or 73% on an equimolar basis.

Preliminary results of consolidation chemotherapy following concurrent chemoradiation after radical surgery in high-risk early-stage carcinoma of the uterine cervix

AIMS

To evaluate the efficacy and toxicity of consolidation chemotherapy after concurrent chemoradiation (CCRT) with 5-fluorouracil (5-FU) and cisplatin in the treatment of high-risk, early stage cervical carcinoma after radical surgery.

MATERIALS AND METHODS

Women with clinical stage IB and IIA cervical carcinoma, initially treated with radical hysterectomy and pelvic lymphadenectomy, and who had positive pelvic lymph nodes, positive margins, parametrial involvement, or all three, were divided into either a CCRT alone group or a consolidation chemotherapy after CCRT group. Three cycles of chemotherapy were given to the CCRT alone group, and six cycles to the consolidation chemotherapy group. Women in each group received 50.4 Gy external radiation in 28 fractions to a standard pelvic field. Chemotherapy consisted of cisplatin 60 mg/m2 (X 1) and 5-FU 1000 mg/m2/d (X 5) every 3 weeks, with the first and second cycles given concurrent with radiation. Survival and toxicity were compared between the two groups.

RESULTS

Forty women were evaluable (25 in the CCRT alone group and 15 in the consolidation chemotherapy group). The estimated 2-year progression-free survival was 87.7% in the CCRT alone group and 67.0% in the consolidation chemotherapy group. The estimated 2-year overall survival was 95.8% in the CCRT alone group and 100% in the consolidation chemotherapy group. However, no significant differences were found in progression-free and overall survival in the two groups (P = 0.17 and P = 0.29, respectively). Grade 2 or higher leukopenia and neutropenia were significantly more frequent in the consolidation chemotherapy group than in the CCRT alone group (P = 0.02 and P < 0.01, respectively).

CONCLUSIONS

Although the sample size was small, and this study was not randomised, these results suggest that consolidation chemotherapy may not improve survival. Rather, it may increase haematologic toxicities for women with high-risk, early stage cervical carcinoma who undergo radical surgery followed by CCRT.

Dlx5 Specifically Regulates Runx2 Type II Expression by Binding to Homeodomain-response Elements in the Runx2 Distal Promoter

Two major isoforms of the Runx2 gene are expressed by alternative promoter usage: Runx2 type I (Runx2-I) is derived from the proximal promoter (P2), and Runx2 type II (Runx2-II) is produced by the distal promoter (P1). Our previous results indicate that Dlx5 mediates BMP-2-induced Runx2 expression and osteoblast differentiation (Lee, M.-H., Kim, Y-J., Kim, H-J., Park, H-D., Kang, A-R., Kyung, H.-M., Sung, J-H., Wozney, J. M., Kim, H-J., and Ryoo, H-M. (2003) J. Biol. Chem. 278, 34387-34394). However, little is known of the molecular mechanisms by which Dlx5 up-regulates Runx2 expression in BMP-2 signaling. Here, Runx2-II expression was found to be specifically stimulated by BMP-2 treatment or by Dlx5 overexpression. In addition, BMP-2, Dlx5, and Runx2-II were found to be expressed in osteogenic fronts and parietal bones of the developing cranial vault and Runx2-I and Msx2 in the sutural mesenchyme. Furthermore, Runx2 P1 promoter activity was strongly stimulated by Dlx5 overexpression, whereas Runx2 P2 promoter activity was not. Runx2 P1 promoter deletion analysis indicated that the Dlx5-specific response is due to sequences between -756 and -342 bp of the P1 promoter, where three Dlx5-response elements are located. Dlx5 responsiveness to these elements was confirmed by gel mobility shift assay and site-directed mutagenesis. Moreover, Msx2 specifically suppressed the Runx2 P1 promoter, and the responsible region overlaps with that recognized by Dlx5. In summary, Dlx5 specifically transactivates the Runx2 P1 promoter, and its action on the P1 promoter is antagonized by Msx2.

Smad-dependent cooperative regulation of interleukin 2 receptor alpha chain gene expression by T cell receptor and transforming growth factor-beta

The interleukin 2 receptor alpha chain (IL-2Ralpha) is a component of high affinity IL-2 receptors and thus critically regulates T cell growth and other lymphoid functions. Five positive regulatory regions together control lineage-restricted and activation-dependent IL-2Ralpha induction in response to antigen and IL-2. We now show that TGF-beta cooperates with T cell receptor (TCR) signaling to increase IL-2Ralpha gene expression. Moreover, we identify a sixth positive regulatory region that regulates IL-2Ralpha expression in cells treated with anti-CD3 + anti-CD28 as well as TGF-beta and show that this region contains binding sites for Smad3, AP-1, and cAMP-responsive element-binding protein/ATF proteins. The importance of Smad complexes is indicated by impaired IL-2Ralpha induction by TGF-beta in CD4+ T cells from both Smad3-/- and Smad4-/- mice. Thus, we have identified a novel positive regulatory region in the IL-2Ralpha gene that mediates TGF-beta-dependent induction of the gene. These findings have implications related to IL-2Ralpha expression on activated T cells and regulatory T cells.

N'-(phenyl-pyridin-2-yl-methylene)-hydrazine carbodithioic acid methyl ester enhances radiation-induced cell death by targeting Bcl-2 against human lung carcinoma cells

To develop a new radiosensitizer, we screened a chemical library and selected one chemical reagent, N'-(phenyl-pyridin-2-yl-methylene)-hydrazine carbodithioic acid methyl ester (PHCM), which was already known to have antifungal and antimicrobial properties. PHCM enhanced radiation-induced cell death and its mean calculated dose enhancement ratio was 1.17. PHCM was found to induce the phosphorylation of p38 mitogen-activated protein kinase, and combined treatment with PHCM and radiation down-regulated Bcl-2. In a xenograft assay, the combined PHCM and radiation group showed 39.3 days of growth delay versus the control in terms of tumor growth. The enhancement factor of this combined treatment was determined to be 4.02.

N′-(phenyl-pyridin-2-yl-methylene)-hydrazine carbodithioic acid methyl ester enhances radiation-induced cell death by targeting Bcl-2 against human lung carcinoma cells

To develop a new radiosensitizer, we screened a chemical library and selected one chemical reagent, N′-(phenyl-pyridin-2-yl-methylene)-hydrazine carbodithioic acid methyl ester (PHCM), which was already known to have antifungal and antimicrobial properties. PHCM enhanced radiation-induced cell death and its mean calculated dose enhancement ratio was 1.17. PHCM was found to induce the phosphorylation of p38 mitogen-activated protein kinase, and combined treatment with PHCM and radiation down-regulated Bcl-2. In a xenograft assay, the combined PHCM and radiation group showed 39.3 days of growth delay versus the control in terms of tumor growth. The enhancement factor of this combined treatment was determined to be 4.02.

Establishment of stable melanoma cell line expressing a novel gene, jpk, using a tetracycline-controlled gene expression system

Jpk, originally isolated as an associating factor with the position-specific regulatory element of Hoxa-7, was found to be toxic to Escherichia coli (1) and to F9 teratocarcinoma cells (2) when transiently transfected and expressed. To investigate the possibility of tumor gene therapy using Jpk, its effect was tested in B16F10 murine melanoma cells. Because Jpk reduces the viability of B16F10 cells when transiently expressed, the Jpk gene was cloned into a tetracycline-controlled gene expression vector, pRetro-On to circumvent the lethal effect in unwanted situations. The retroviral plasmid pRetroJpk purified from the packaging cell was infected into B16F10 melanoma cells and screened in the presence of puromycin. Out of a total of 53 stable clones selected with puromycin, two clones overexpressed Jpk at more than twice the level when induced by doxycycline, a tetracycline-derivative, which implies the amount of the Jpk exhibiting the toxicity is critical. Although these clones control only low levels of Jpk, overexpression of the established melanoma cell line may help us decipher the function of Jpk and apply it as a tumor therapeutic gene in the future.

Percolative Superconductivity in Mg1-xB2

Our results from various transport experiments on Mg1-xB2 indicate a surprising effect associated with the presence of a Mg deficiency in MgB2: the phase separation between Mg-vacancy rich and Mg-vacancy poor phases. The Mg-vacancy poor phase is superconducting, but the insulating nature of the Mg-vacancy rich phase probably originates from the Anderson (disorder-induced) localization of itinerant carriers. Furthermore, electron diffraction measurements indicate that within vacancy-rich regions these defects tend to order with intriguing patterns. This electronic phase separation in Mg1-xB2 shows similar, but also distinct characteristics compared with that observed in La(2)CuO(4+delta).

Functional expression of distinct NMDA channel subunits tagged with green fluorescent protein in hippocampal neurons in culture

We generated expression vectors for N-terminally green fluorescent protein -tagged NR2A and NR2B subunits (GFP-NR2A and GFP-NR2B). Both constructs expressed GFP and formed functional NMDA channels with similar properties to untagged controls when co-transfected with NR1 subunit partner in HEK293 cells. Primary cultured hippocampal neurons were transfected at five days in vitro with these vectors. Fifteen days after transfection, well-defined GFP clusters were observed for both GFP-NR2A and GFP-NR2B subunits being co-localized with endogenous NR1 subunit. Whole-cell recordings showed that the GFP-NR2A subunit determined the decay of NMDA-mediated miniature spontaneous excitatory postsynaptic currents (NMDA-mEPSCs) in transfected neurons. Live staining with anti-GFP antibody demonstrated the surface expression of GFP-NR2A and GFP-NR2B subunits that was partly co-localized a presynaptic marker. Localization of NMDA receptor clusters in dendrites was studied by co-transfection of CFP-actin and GFP-NR2 subunits followed by anti-GFP surface staining. Within one week after plating most surface NMDAR clusters were distributed on dendritic shafts. Later in development, a large portion of surface clusters for both GFP-NR2A and GFP-NR2B subunits were clearly localized at dendritic spines. Our report provides the basis for studies of NMDA receptor location together with dendritic dynamics in living neurons during synaptogenesis in vitro.