Development of a Potential-Modulated Electrochemiluminescence Measurement System for Selective and Sensitive Determination of the Controlled Drug Codeine

Codeine is a common analgesic drug that is a pro-drug of morphine. It also has a high risk of abuse as a recreational drug because of its extensive distribution as an OTC drug. Therefore, sensitive and selective screening methods for codeine are crucial in forensic analytical chemistry. To date, a commercial analytical kit has not been developed for dedicated codeine determination, and there is a need for an analytical method to quantify codeine in the field. In the present work, potential modulation was combined with electrochemiluminescence (ECL) for sensitive determination of codeine. The potential modulated technique involved applying a signal to electrodes by superimposing an AC potential on the DC potential. When tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)3]2+) was used as an ECL emitter, ECL activity was confirmed for codeine. A detailed investigation of the electrochemical reaction mechanism suggested a characteristic ECL reaction mechanism involving electrochemical oxidation of the opioid framework. Besides the usual ECL reaction derived from the amine framework, selective detection of codeine was possible under the measurement conditions, with clear luminescence observed in an acidic solution. The sensitivity of codeine detection by potential modulated-ECL was one order of magnitude higher than that obtained with the conventional potential sweep method. The proposed method was applied to codeine determination in actual prescription medications and OTC drug samples. Codeine was selectively determined from other compounds in medications and showed good linearity with a low detection limit (150 ng mL-1).

Sensitive screening of methamphetamine stimulant using potential-modulated electrochemiluminescence

Methamphetamine (MA) is one of the most commonly abused recreational stimulants; thus, rapid and sensitive screening methods for MA are of great importance in forensic analytical chemistry. In the present work, potential modulation was combined with electrochemiluminescence (ECL) for the sensitive determination of MA. The potential modulated (PM) technique involved applying a signal to electrodes by superimposing an alternating current potential on the direct current potential. When tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)₃²⁺) was used as an ECL emitter, the sensitivity of MA detection by PM-ECL was over 100 times that obtained with in conventional potential sweep mode. The radical on the α-carbon of the amine moiety is thought to play an important role in the ECL reaction mechanism involving amine-containing species. However, in the case of MA-type stimulants, density functional theory calculations suggest that the generated α-carbon radicals induce further intramolecular proton transfer. On the basis of the proposed ECL reaction route, we clarified the conditions under which MA could be selectively detected in the presence of the similar substance methoxyphenamine. The proposed method was applied to MA determination in a spiked human urine sample and showed good linearity with a low detection limit (100 nM, ca. 15 ng mL^-1).

Electrochemiluminescence of Tris(2,2'-bipyridine)ruthenium(II)/Tri-n-propylamine with an Electric Contactless Power Transfer System

An electrochemiluminescence (ECL) analytical device was developed using an electric contactless power transfer system. A mutually induced electromotive voltage was generated by wrapping an enameled wire around a commercial contactless charger. There was no electrical contact between the power supply and the electrochemical cell. For the tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)₃²⁺)/tri-n-propylamine system, a weak ECL signal was observed. When an inexpensive rectifier diode was introduced between the coil and the working electrode, the ECL intensity detection sensitivity increased by more than 100 times. The relationship between the waveform of the applied voltage and the ECL response was clarified, and the optimum conditions were determined. The intensity of the induced electromotive voltage was easily controlled by changing the number of turns in the coil. The proposed method is a safe, simple, and inexpensive technique without electrical contact.

Potential-modulated electrochemiluminescence of a tris(2,2'-bipyridine)ruthenium(II) / lidocaine system under 430 kHz ultrasound irradiation

The electrochemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)₃²⁺) in the presence of lidocaine was investigated under ultrasound (US) irradiation. The sonoelectrochemical experiments are conducted by indirect irradiation of ultrasound with a piezoelectric transducer operating at 430 kHz. In a supporting electrolyte at pH 11, the Ru(bpy)₃²⁺/lidocaine system gave weak ECL peaks around +1.2 V and +1.45 V, respectively. The ECL signal at +1.2 V was attributed to redox reactions of the oxidative intermediates of Ru(bpy)₃²⁺ and lidocaine, while the signal at +1.45 V was assumed to be caused by an advanced oxidation process due to the generation of hydroxyl radicals (OH) at the electrode surface. In this study, the potential modulation approach is employed in the study of ECL process upon US irradiations because it can suppress the noise components from sonoluminescence effectly and improve the resolution of ECL-potential profiles. It is found ECL signals were greatly enhanced upon US irradiation at the output power of 30 W, however, the relative intensity of ECL signal at +1.2 V was larger than that obtained with a rotating disk electrode even though the mass transport effect is equilvalent. The experiment results suggest that the chemical effect (i.e., generation of OH) by 430 kHz US becomes remarkable in the electrochemical process. Detailed ECL reaction routes under US are proposed in this study.

High-Frequency Heating Extraction Method for Sensitive Drug Analysis in Human Nails

Background: A simple, sensitive, and rapid extraction method based on high-frequency (H-F) heating was developed for drug analysis in human nails. Methods: A human nail was placed in a glass tube with an extraction solvent (methanol and 0.1% formic acid; 7:3, v/v), and a ferromagnetic alloy (pyrofoil) was wrapped in a spiral around the glass tube. Then, the glass tube was placed in a Curie point pyrolyzer, and a H-F alternating voltage (600 kHz) was applied. The sample and extraction solvent were heated at the Curie temperature for 3 min. Different Curie temperatures were applied by changing the pyrofoil (160 °C, 170 °C, 220 °C, and 255 °C). Results: The caffeine in the nail was effectively and rapidly extracted into the extraction solvent with the pyrofoil at 220 °C. The peak area obtained for the caffeine using liquid chromatography mass spectrometry (LC-MS/MS) was five times that of what was obtained after conventional ultrasonic irradiation extraction. Because the extraction uses high-pressure and high-temperature conditions in a test tube, the drugs that were strongly incorporated in nails could be extracted into the solvent. The amount of caffeine extracted was independent of the size of the pieces in the sample. Conclusions: Therefore, the sensitive determination of target drugs in nails is possible with rapid (20 min, including H-F extraction for 3 min) and simple sample preparation. The developed method was applied to a nail from a patient with hypertension.

Sonochemical preparation of gold nanoparticles for sensitive colorimetric determination of nereistoxin insecticides in environmental samples

A simple colorimetric method using gold nanoparticles (AuNPs) was developed as an efficient strategy for specific and sensitive detection of insecticides that are analogs of nereistoxin (NRT). The AuNPs were synthesized by a surfactant-free sonochemical reaction with ultrasonication at 430 kHz. A color change occurred in the presence of NRT because the AuNPs aggregated if they were coated with a small amount of thioctic acid (TA). At a pH of around 5, the TA adsorbed on the AuNPs was deprotonated, whereas NRT was protonated (NRT-H⁺). Adsorption of NRT-H⁺ onto the TA-coated AuNPs surface would decrease the surface charge of the AuNPs, and this resulted in aggregation. Because the aggregation of the TA-coated AuNPs could not be induced by amine compounds without thiol groups, this provided a surface-limited aggregation mechanism for specific sensing of NRT. The absorbance at 700 nm was dependent on the concentration of NRT, and the calibration curve was linear over the concentration range 85 nM (12 ng/mL) to 1000 nM (140 ng/mL). The applicability of the proposed method to detection of trace levels of NRT in environmental water samples was successfully demonstrated using a simple liquid-liquid reverse extraction technique.

Application of the Self- Assembling Peptide P11-4 for Prevention of Acidic Erosion

The aim of this study was to use ultrasonography to evaluate the effect of the self-assembling peptide P11-4 on acid erosion prevention. Curodont Repair (CR), which includes peptide P11-4, was used. Rectangular prisms of bovine enamel (4×1×1 mm) were immersed in pure orange juice for a period of 5 minutes six times per day for 28 days. These samples were divided into four groups of six specimens each and treated differently for an additional period of 28 days: 1) baseline group specimens were stored in artificial saliva; 2) CR group specimens were exposed to curodont without acid challenge; 3) NCRA (no curodont+acid challenge) specimens were treated with orange juice without curodont exposure; and 4) CRA (CR+acid challenge) specimens were treated with curodont before treatment with orange juice. The propagation time of longitudinal ultrasonic velocity (UV) was measured. Ultrastructural observation of each tested enamel surface was carried out using field-emission scanning electron microscopy (SEM). The UV data were analyzed using two-way analysis of variance with time and treatment as confounding factors. Post hoc pairwise tests among groups were performed using the Tukey honestly significant difference test. The average UV in intact bovine enamel for the baseline group ranged from 4,483 to 4,549 m/s and did not vary significantly within the test period. The average ultrasonic velocity (UV) in all samples decreased after the initial erosion. The UV in NCRA decreased further over time. Increased UVs were found for CR and CRA. For CR and CRA, there was no significant difference in UV at the end of the experiment from the initial value before erosion. In the results of SEM observation, the CR and CRA groups had similar morphologic features in that etching patterns were not clearly due to precipitation between the enamel rods. From the results of this in vitro study, it might be concluded that applying enamel matrix derivatives and self-assembling peptides on erosive lesions can improve remineralization.

Development and application of ultrasound-assisted microextraction to analysis of fenitrothion in environmental samples

A microextraction technique based on ultrasonic emulsification and demulsification was developed for detecting pesticides at trace levels in environmental water samples. In this ultrasound-assisted microextraction (UAME), chloroform was emulsified with an aqueous sample solution containing trace fenitrothion (MEP) by ultrasonic irradiation (48 kHz) for 5 min. The emulsion was then demulsified by ultrasonic irradiation (2.4 MHz) for 10 min. This resulted in phase separation of the water and chloroform without centrifugation. The demulsified chloroform was collected by a microsyringe and submitted to gas chromatography-mass spectrometry. In conventional extraction with mechanical stirring, the extraction recovery (ER) of MEP was strongly dependent on the sample/chloroform volume ratio. However, in UAME, the ER was independent of the volume ratio and the ER was >80 % when the enrichment factor was 40. In UAME, MEP was rapidly extracted into the chloroform because of the large specific surface areas of the small chloroform droplets in the oil-in-water (O/W) emulsion. This gave a high extraction efficiency for MEP. UAME is a simple method requiring only a change in the ultrasound frequency and with no pretreatment steps that could contaminate the sample. The suitability of UAME was demonstrated by application to the detection of trace levels of pesticides in a spiked water sample from a fish tank. Graphical abstract Schematic diagram of the ultrasound-assisted microextraction (UAME) method.

Influence of Hydrocarbon Moiety of DMMP on Flame Propagation in Lean Mixtures

Phosphorus-containing compounds (PCCs) have been found to be significantly more effective than CF₃Br for reducing burning velocity when added to stoichiometric hydrocarbon-air flames. However, when added to lean flames, DMMP (dimethylmethylphosphonate) is predicted to increase the burning velocity. The addition of DMMP to lean mixtures apparently increases the equivalence ratio (fuel/oxidizer) and the combustion temperature, as a result of hydrocarbon content of DMMP molecule. Premixed flames studies with added DMMP, OP(OH)₃, and CF₃Br are used to understand the different behavior with varying equivalence ratio and agent loading. Decrease of the equivalence ratio leads to the decrease of inhibition effectiveness of PCCs relative to bromine-containing compounds. For very lean mixtures CF₃Br becomes more effective inhibitor than PCCs. Calculations of laminar burning velocities for pure DMMP/air mixtures predict the maximum burning velocity of 10.5 cm/s at 4.04 % of DMMP in air and at an initial temperature of 400 K. Adiabatic combustion temperature is 2155 K at these conditions.

Quality-of-life outcomes from a randomized phase III trial of dose-dense weekly paclitaxel and carboplatin compared with conventional paclitaxel and carboplatin as a first-line treatment for stage II-IV ovarian cancer: Japanese Gynecologic Oncology Group Trial (JGOG3016)

BACKGROUND

Dose-dense weekly paclitaxel (Taxol) and carboplatin (dd-TC) improved survival compared with conventional tri-weekly paclitaxel and carboplatin (c-TC) as a first-line chemotherapy for newly diagnosed stage II-IV ovarian cancer in the Japanese Gynecologic Oncology Group 3016 trial. We report the quality-of-life (QoL) results from this trial.

PATIENTS AND METHODS

A total of 637 patients were randomly assigned to receive c-TC or dd-TC (c-TC, n = 319; dd-TC, n = 312) and were asked to complete a QoL assessment at baseline, just after the third and sixth chemotherapy cycles, and at 12 months after randomization. QoL was assessed using Functional Assessment of Cancer Therapy (FACT)-general (FACT-G), FACT-taxane subscale (FACT-T), and FACT-ovary subscale (FACT-Ov). The overall QoL and that according to each subscale were analyzed using mixed-effects models adjusted for treatment and time.

RESULTS

Baseline QoL assessment was completed by 204 out of 319 (63.9%) and 200 out of 312 (64.1%) patients in the c-TC and dd-TC groups, respectively. In these groups, the compliance rates with regard to QoL assessment were 74.5% and 73.0%, respectively, after three chemotherapy cycles; 86.8% and 86.9%, respectively, after six chemotherapy cycles; and 74.2% and 71.6%, respectively, at 12 months after randomization. The overall QoL did not differ significantly between the two treatment groups up to 12 months after randomization (P = 0.46). However, QoL according to the FACT-T subscale was significantly lower in the dd-TC group than in the c-TC group (P = 0.02).

CONCLUSION

dd-TC does not decrease overall QoL compared with c-TC.

Randomized trial of preoperative docetaxel with or without capecitabine after 4 cycles of 5-fluorouracil– epirubicin–cyclophosphamide (FEC) in early-stage breast cancer: exploratory analyses identify Ki67 as a predictive biomarker for response to neoadjuvant chemotherapy

This randomized, multicenter study compared the efficacy of docetaxel with or without capecitabine following fluorouracil/epirubicin/cyclophosphamide (FEC) therapy in operable breast cancer and investigated the role of Ki67 as a predictive biomarker. Patients were randomized to 4 cycles of docetaxel/capecitabine (docetaxel: 75 mg/m² on day 1; capecitabine: 1,650 mg/m² on days 1–14 every 3 weeks) or docetaxel alone (75 mg/m² on day 1 every 3 weeks) after completion of 4 cycles of FEC (5-fluorouracil 500 mg/m², epirubicin 100 mg/m² and cyclophosphamide 500 mg/m² on day 1 every 3 weeks). The primary endpoint was the pathological complete response (pCR) rate. Predictive factor analysis was conducted using clinicopathological markers, including hormone receptors and Ki67 labeling index (Ki67LI). A total of 477 patients were randomized; the overall response in the docetaxel/capecitabine and docetaxel groups was 88.3 and 87.4 %, respectively. There were no significant differences in the pCR rate (docetaxel/capecitabine: 23 %; docetaxel: 24 %; p = 0.748), disease-free survival, or overall survival. However, patients with mid-range Ki67LI (10–20 %) showed a trend towards improved pCR rate with docetaxel/capecitabine compared to docetaxel alone. Furthermore, multivariate logistic regression analysis showed pre-treatment Ki67LI (odds ratio 1.031; 95 % CI 1.014–1.048; p = 0.0004) to be a significant predictor of pCR in this neoadjuvant treatment setting. Docetaxel/capecitabine (after 4 cycles of FEC) did not generate significant improvement in pCR compared to docetaxel alone. However, exploratory analyses suggested that assessment of pre-treatment Ki67LI may be a useful tool in the identification of responders to preoperative docetaxel/capecitabine in early-stage breast cancer.

Ovulation compensatory function after unilateral ovariectomy in dogs

As a step towards elucidation of the timing and mechanism of the determination of the number of ovulated ova in dogs, we excised one ovary 2, 5 and 8 days after the beginning of vulval bleeding and examined whether the lost ovulation function, assessed by estimating the number of ovulated oocytes, would be compensated for by the remaining ovary. The number of ovulated ova was maintained by the remaining ovary in the group that underwent unilateral ovariectomy 2 days after the beginning of vulval bleeding. However, in the groups ovariectomized 5 or 8 days after the beginning of vulval bleeding, no compensation for the number of ova that would have been ovulated from the lost ovary was observed; ova were ovulated only from the follicles 3 mm or greater in diameter observed in the remaining ovary at unilateral ovariectomy. Thus, in dogs, the number of ovulated ova is considered to be determined within 5 days after the beginning of vulval bleeding.

Abstract P1-14-02: Preoperative docetaxel (T) with or without capecitabine (X) following epirubicin, 5-fluorouracil and cyclophosphamide (FEC) in patients with operable breast cancer (OOTR N003): Results of comparative study and predictive marker analysis

Objective: This preoperative study aimed to evaluate the efficacy of 4 cycles of TX compared with 4 cycles of T, following 4 cycles of FEC in operable breast cancer patients.

Methods: Women with operable breast cancer (T1C-3N0M0/T1-3N1M0) were randomly assigned to receive either T (75 mg/m2, q3) plus X (825 mg/m2 bid, days 1 to 14) or T alone (75 mg/m2, q3) after completion of FEC (5-fluorouracil 500 mg/m2, epirubicin 100 mg/m2, cyclophosphamide 500 mg/m2, q3). Patients who had disease progression on FEC were excluded from randomization. The primary endpoint was pathological complete response (pCR). Predictive factor analysis was conducted using clinicopathological markers such as hormone receptors, Ki67 labeling index (Ki67LI) and thymidine phosphorylase (TP).

Results: From November 2005 to October 2009, 504 patients were enrolled and 239 and 238 patients were assigned to TX and T group, respectively (median age 49 years, median tumor size 3.5 cm and node positive rate 56%). Treatment discontinuation was observed in 22% of TX group and 5% in T group (p < 0.0001). The major reasons for discontinuation were toxicity, refusal/ consent withdrawal and several others. No significant difference in pCR rate was shown between the two groups (TX 23% and T 24%, p = 0.748). Neither clinical response nor surgical outcome differed between TX and T. The pCR rate in patients who had therapy discontinuation or dose-reduction on TX was 23%, whereas pCR rate in those on T was 11%. A subpopulation treatment effect pattern plots method indicated a trend that TX may improve the pCR rate in patients having a middle range of pretreatment Ki67LI, such as 10%–20%. In the median follow-up time of 3.7 years, disease-free survival (DFS) was not different between TX and T (3-year DFS: 92% in TX and 91% in T; hazard ratio 0.907, 95%CI 0.528–1.557, p = 0.723). The frequency of major grade 3 or greater adverse events of TX and T were leukopenia, 36% and 34%, febrile neutropenia 8% and 5%, and hand-foot syndrome 15% and 2%, respectively.

According to the analysis for evaluating predictive values of biomarkers, a multivariate logistic regression analysis showed that HER2 (+/−: odds ratio 4.107, p < 0.0001), Ki67LI (continuous variables: 1.029, p = 0.003), hormone receptor status (+/−: 0.457, p = 0.009), stroma TP status (0.523, p = 0.02) and grade (1/3: 0.387, 2/3: 0.532, p = 0.047) had statistical significant values for predicting pCR. A multiple Cox model in landmark analysis showed that tumor size (p < 0.0001), cancer cell TP status (p = 0.005), pCR and posttreatment Ki67LI (p = 0.016), and age (p = 0.049) were associated with DFS significantly.

Conclusions: Addition of X to T showed no superiority to T alone following FEC in neoadjuvant treatment of these patients with operable breast cancer. Treatment discontinuation rate was significantly higher in TX than T group, however the pCR rate in patients in TX group who required treatment discontinuation or dose-reduction was similar to that in patients who completed as scheduled, which was different from T group. Determination of pre-/ post-treatment Ki67LI looks useful for predicting pCR and DFS.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-14-02.

Enhanced removal of sodium salts supported by in-situ catalyst synthesis in a supercritical water oxidation process

For practical applications of supercritical water oxidation to wastewater treatment, the deposition of inorganic salts in supercritical phase must be controlled to prevent a reactor from clogging. This study investigated enhanced removal of sodium salts with titanium particles, serving as a salt trapper and a catalyst precursor, and sodium recovery by sub-critical water. When Na(2)CO(3) was tested as a model salt, sodium removal efficiency was higher than theoretically maximum efficiency defined by Na(2)CO(3) solubility. The enhanced sodium removal resulted from in-situ synthesis of sodium titanate, which could catalyse acetic acid oxidation. The kinetics of sodium removal was described well by a diffusion mass-transfer model combined with a power law-type rate model of sodium titanate synthesis. Titanium particles showed positive effect on sodium removal in the case of NaOH, Na(2)SO(4) and Na(3)PO(4). However, they had negligible effect for NaCl and negative effect for Na(2)CrO(4), respectively. More than 99% of trapped sodium was recovered by sub-critical water except for Na(2)CrO(4). In contrast, sodium recovery efficiency remained less than 50% in the case of Na(2)CrO(4). Reused titanium particles showed the same performance for enhanced sodium removal. Enhanced salt removal supported by in-situ catalyst synthesis has great potential to enable both salt removal control and catalytic oxidation.

Development of a web-based CT dose calculator: WAZA-ARI

A web-based computed tomography (CT) dose calculation system (WAZA-ARI) is being developed based on the modern techniques for the radiation transport simulation and for software implementation. Dose coefficients were calculated in a voxel-type Japanese adult male phantom (JM phantom), using the Particle and Heavy Ion Transport code System. In the Monte Carlo simulation, the phantom was irradiated with a 5-mm-thick, fan-shaped photon beam rotating in a plane normal to the body axis. The dose coefficients were integrated into the system, which runs as Java servlets within Apache Tomcat. Output of WAZA-ARI for GE LightSpeed 16 was compared with the dose values calculated similarly using MIRD and ICRP Adult Male phantoms. There are some differences due to the phantom configuration, demonstrating the significance of the dose calculation with appropriate phantoms. While the dose coefficients are currently available only for limited CT scanner models and scanning options, WAZA-ARI will be a useful tool in clinical practice when development is finalised.

Breast tumor progression induced by loss of BTG2 expression is inhibited by targeted therapy with the ErbB/HER inhibitor lapatinib

The B-cell translocation gene-2 (BTG2), a p53-inducible gene, is suppressed in mammary epithelial cells during gestation and lactation. In human breast cancer, decreased BTG2 expression correlates with high tumor grade and size, p53 status, blood and lymph vessel invasion, local and metastatic recurrence and decrease in overall survival, suggesting that suppression of BTG2 has a critical role in disease progression. To analyze the role of BTG2 in breast cancer progression, BTG2 expression was knocked down in mammary epithelial cells. Suppression of BTG2 enhances the motility of cells in vitro and tumor growth and metastasis in vivo. The effects of BTG2 knockdown are mediated through stabilization of the human epidermal growth factor receptor (HER) ligands neuregulin and epiregulin and activation of the HER2 and HER3 receptors, leading to elevated AKT phosphorylation. Suppression of HER activation using the tyrosine kinase inhibitor lapatinib abrogates the effects of BTG2 knockdown, including the increased cell migration observed in vitro and the enhancement of tumorigenesis and metastasis in vivo. These results link BTG2-dependent effects on tumor progression to ErbB receptor signaling, and raise the possibility that targeted inhibition of this pathway may be relevant in the treatment of breast cancers that have reduced BTG2 expression.

Analysis of the effect of structural materials in a wall-less tissue-equivalent proportional counter irradiated by 290 MeV u(-1) carbon beam

Effects of structural materials in a wall-less tissue-equivalent proportional counter were evaluated based on the calculation of energy deposits by EGS5 and the measurement of lineal energy distributions using 290 MeV u(-1) carbon beams. It is found that the correction of measured data based on simulation is necessary for understanding the energy deposition spectra in the homogeneous condition in tissues.

HOXB9 Promotes the Acquisition of Tumorigenic Phenotypes in Mammary Epithelial Cells

Background:The class I HOX gene family consists of 39 members with a shared highly conserved 61-amino acid homeodomain motif. HOX genes are important regulators of developmental processes, and their role in neoplastic transformation and tumor progression is increasingly recognized (Abate-Shen et al., Nat Rev Cancer, 2002; Cantile et al., Eur J Cancer, 2003). However, the molecular mechanisms by which HOX proteins promote tumorigenesis is not well understood. We recently, observed that HOXB9, a 9th HOX gene paralogue involved in mouse mammay gland development, is deregulated in breast cancer and enhanced expression correlated with high tumor grade. A role for elevated HoxB9 expression in breast tumor progression is demontrated by its ability to activate the ErbB and TGF-B pathways which influence tumor-associated phenotypes in cells.Methods and results:Overexpression of HOXB9 was found in 43% of primary breast cancer by RT-PCR and in situ hybridization (Figure 1A) and correlated with high tumor grade. Ectopic expression of HOXB9 in MCF10A mammary epithelial cells induced EMT, cell migration, invasion (Figure 1B, and 1C). It also increased the expression of angiogenic factors, which enhance the formation of new vessels in mouse dorsal air sac model. Conversely, genetic ablation of endogenous HOXB9 in MDA-MB-231 breast cancer cells suppresses their motility and angiogenic potential. Further, we confirmed that HOXB9-induced tumor phenotypes arise through the activation of both ErbB-AKT and TGFß signaling pathways. Finally, in mouse xenograft model, we observed that HOXB9 cooperates with activated H-Ras to transform mammary epithelial cells leading to large, vascularized and invasive tumors (Figure 2).Discussion:Our findings imply that overexpression of HOXB9 in human breast cancer contributes to tumor progression through activation of signaling pathways that alter both tumor-specific cell fates and tumor-stromal microenvironment, leading to increased invasion and metastasis. It is suggested that combined suppression of ErbB and TGFß signaling pathways to target breast cancers overexpressing HOXB9 may be effective in tumor inhibition.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6145.

Accurate dose assessment system for an exposed person utilising radiation transport calculation codes in emergency response to a radiological accident

A system has been developed to assess radiation dose distribution inside the body of exposed persons in a radiological accident by utilising radiation transport calculation codes-MCNP and MCNPX. The system consists mainly of two parts, pre-processor and post-processor of the radiation transport calculation. Programs for the pre-processor are used to set up a 'problem-dependent' input file, which defines the accident condition and dosimetric quantities to be estimated. The program developed for the post-processor part can effectively indicate dose information based upon the output file of the code. All of the programs in the dosimetry system can be executed with a generally used personal computer and accurately give the dose profile to an exposed person in a radiological accident without complicated procedures. An experiment using a physical phantom was carried out to verify the availability of the dosimetry system with the developed programs in a gamma ray irradiation field.

Numerical system utilising a Monte Carlo calculation method for accurate dose assessment in radiation accidents

A system utilising radiation transport codes has been developed to derive accurate dose distributions in a human body for radiological accidents. A suitable model is quite essential for a numerical analysis. Therefore, two tools were developed to setup a 'problem-dependent' input file, defining a radiation source and an exposed person to simulate the radiation transport in an accident with the Monte Carlo calculation codes-MCNP and MCNPX. Necessary resources are defined by a dialogue method with a generally used personal computer for both the tools. The tools prepare human body and source models described in the input file format of the employed Monte Carlo codes. The tools were validated for dose assessment in comparison with a past criticality accident and a hypothesized exposure.

[RNA-interference, induced by transient and continuous expression of hairpin RNA in cells from Drosophila and mammals]

RNA interference (RNAi) may be induced by a plasmid with an inverted repeat (IR) sequence directing transcription of hairpin-type double-stranded RNA (dsRNA). This study examines the effects of changing various parameters of IR constructs on Drosophila and mammalian RNAi, using the dual luciferase system, RNAi activity was found to vary depending on IR length ass well as the length and sequence of the internal loop separating sense and antisense sequences. Both transient and stable RNAi occurred in Drosophila cultured cells. Although transient DNA-mediated RNAi was noted in most mammalian cells, no mammalian cells stably possessing IR sequences and hence RNAi activity could be obtained. In Drosophila, DNA-mediated RNAi was considerably weaker than long-dsRNA-mediated RNAi. The cytological data indicated that this was most probably caused by abortive processing of hairpin RNA produced within cells. DNA-mediated RNAi was examined at the level of Drosophila individuals using extramacrochaetae as a model gene, and the presence of an intron sequence in the single-stranded loop region was shown to be essential for effective RNAi.

Analyses of absorbed dose to tooth enamel against external photon exposure

Absorbed dose to tooth enamel was examined against external photon exposure by measurements with thermoluminescence dosemeters (TLDs) and Monte Carlo calculations. TLDs were placed in a realistic physical phantom to measure dose to the teeth region in a head. A voxel-type phantom was constructed from computed tomography (CT) images of the physical phantom. Monte Carlo calculations with this voxel-type phantom were performed to analyse the results of the experiments. The data obtained were compared to the enamel doses, which were calculated with a modified MIRD-type phantom and already given in a previous paper. It was confirmed that the data derived with the MIRD-type phantom are applicable for retrospective individual dose assessments by electron spin resonance (ESR) dosimetry using teeth for the photon energy region above 300 keV. The analysis, however, indicated that the configuration of the head can affect the enamel dose relative to external exposure to photons with energy below 100 keV.

Dose assessment from activated sodium within a body in criticality accidents

Some data were derived using recent sophisticated methods to rapidly convert specific activity of induced 24Na to average dose over a whole body in criticality accidents. Monte Carlo calculations using the MCNP-4B code were performed to study energy spectra of neutrons and gamma rays for some criticality systems with fissile uranium. Absorbed dose to the human body and the activation of sodium were also analysed against external radiation by simulations using a MIRD-5 type phantom and the calculated energy spectra. It was found that the neutron dose assessment from induced 24Na would be important to give medical staff initial guidance for treatment of a victim. However, the energy distribution of incident neutrons to the human body did not significantly influence the conversion from the specific activity of 24Na to dose from gamma rays induced within a body. Analyses were made to clarify the dependence of conversion from 24Na specific activity to neutron dose on the orientation toward the source and the size of the human body. The total dose estimated based upon the obtained data ranged from 33 mGy to 514 mGy for a given specific activity of 1.4 kBq 24Na per g 23Na for some criticality assemblies. This study suggested that the size of uranium solution and material around the fuel should be defined to properly estimate the total dose, including the dose from external photons.