Low nanomolar concentrations of Cucurbitacin-I induces G2/M phase arrest and apoptosis by perturbing redox homeostasis in gastric cancer cells in vitro and in vivo

Cucurbitacin-I (Cu-I, also known as Elatericin B or JSI-124) is developed to inhibit constitutive and abnormal activation of STAT3 in many cancers, demonstrating a potent anticancer activity by targeting disruption of STAT3 function. Here, we for the first time systematically studied the underlying molecular mechanisms of Cu-I-induced gastric cancer cell death both in vitro and in vivo. In our study, we show that Cu-I markedly inhibits gastric cancer cell growth by inducing G2/M phase cell cycle arrest and apoptosis at low nanomolar concentrations via a STAT3-independent mechanism. Notably, Cu-I significantly decreases intracellular GSH/GSSG ratio by inhibiting NRF2 pathway to break cellular redox homeostasis, and subsequently induces the expression of GADD45α in a p53-independent manner, and activates JNK/p38 MAPK signaling. Interestingly, Cu-I-induced GADD45α and JNK/p38 MAPK signaling form a positive feedback loop and can be reciprocally regulated by each other. Therefore, the present study provides new insights into the mechanisms of antitumor effects of Cu-I, supporting Cu-I as an attractive therapeutic drug in gastric cancer by modulating the redox balance.

Epigenetic silencing of GDF1 disrupts SMAD signaling to reinforce gastric cancer development

Accumulating evidence reveals the effectiveness of epigenetic therapy in gastric cancer. However, the molecular mechanisms and targets underlying such therapeutic responses remain elusive. Herein, we report an aberrant yet therapeutically rectifiable epigenetic signaling in gastric carcinogenesis. Administration of DNA-demethylating drug 5-aza-2'-deoxycytidine (5-aza-dC) reduced gastric cancer incidence by ~74% (P < 0.05) in N-nitroso-N-methylurea-treated mice. Through genome-wide methylation scanning, novel promoter hypermethylation-silenced and drug-targeted genes were identified in the resected murine stomach tumors and tissues. We uncovered that growth/differentiation factor 1 (Gdf1), a member of the transforming growth factor-β superfamily, was silenced by promoter hypermethylation in control tumor-bearing mice, but became reactivated in 5-aza-dC-treated mice (P < 0.05). In parallel, the downregulated SMAD2/3 phosphorylation in gastric cancer was revived by 5-aza-dC in vivo. Such hypermethylation-dependent silencing and 5-aza-dC-mediated reactivation of GDF1-SMAD2/3 activity was conserved in human gastric cancer cells (P < 0.05). Subsequent functional characterization further revealed the antiproliferative activity of GDF1, which was exerted through activation of SMAD2/3/4-mediated signaling, transcriptional controls on p15, p21 and c-Myc cell-cycle regulators and phosphorylation of retinoblastoma protein. Clinically, hypermethylation and loss of GDF1 was significantly associated with reduced phosphorylated-SMAD2/3 and poor survival in stomach cancer patients (P < 0.05). Taken together, we demonstrated a causal relationship between DNA methylation and a tumor-suppressive pathway in gastric cancer. Epigenetic silencing of GDF1 abrogates the growth-inhibitory SMAD signaling and renders proliferation advantage to gastric epithelial cells during carcinogenesis. This study lends support to epigenetic therapy for gastric cancer chemoprevention and identifies a potential biomarker for prognosis.

Stillbirth: Genome-wide copy number variation profiling in archived placental umbilical cord samples with pathologic and clinical correlation

INTRODUCTION

Stillbirth remains a devastating health issue with 26,000 stillbirths occurring annually in the United States. Formalin-fixed, paraffin-embedded (FFPE) umbilical cord samples are available for many stillbirths. Our aim was to validate the use of these samples in identifying genetic variations in stillbirth through microarray analysis.

METHODS

This is a retrospective case-control study from a single institution of stillbirths ≥ 23 weeks gestational age and control liveborn infants. Fetal genomic DNA was extracted from FFPE umbilical cord samples of stillborn and control placentas, and genotyping was performed using the Illumina HumanOmniExpresss-12v1 Beadchip. Array results were verified with qPCR.

RESULTS

31 case-specific CNVs (17 deletions and 14 amplifications) with an average size of 294 kb for amplifications and 74 kb for deletions were identified among 94 FFPE samples (86 cases; 8 controls). In total 38 (44%) of the stillbirth samples had a CNV detected. Validation of a subset of microarray findings with qPCR confirmed deletions on 1p (2 cases), 11q (4 cases) and amplifications on 18 (1 case). Placental underperfusion changes were seen in stillborns with deletions on 1p, a region containing complement regulatory genes which have been shown to play a role in preeclampsia.

DISCUSSION

This study validated the use of archived FFPE umbilical cord samples for genome-wide copy number profiling in stillbirths, and demonstrates specific CNV deletions and amplifications. Microarray analysis in an expanded cohort of stillbirth FFPE samples has the potential to identify biomarkers involved in stillbirth pathogenesis.

Effect of nitric oxide inhalation combined with high-frequency oscillatory ventilation on the prognosis of neonatal severe hypoxemia

OBJECTIVE

The current study aimed to analyze the short-term and long-term curative effects of nitric oxide (NO) inhalation combined with high-frequency oscillatory ventilation (HFOV) on neonatal severe hypoxemia.

MATERIALS AND METHODS

A total of 98 neonates meeting the inclusion criteria were retrospectively analyzed. The control group comprised of 48 neonates and the NO inhalation group consisted of 50 neonates. In the control group, conventional mechanical ventilation was replaced by HFOV. In the experimental group, NO inhalation combined with HFOV was performed. The death rates within 28 days, mechanical ventilation and oxygen therapy time, and complications in both groups were observed. The survivors in both groups were followed up for 18 months for neural development evaluation.

RESULTS

The treatment group showed a significantly lower death rate and noticeably shorter mechanical ventilation and oxygen therapy time than the control group (8% vs. 22.9% with t = 4.20 andp < 0.05; 5.84 ± 3.36 days vs. 8.05 ± 5.48 days with t = 2.42 and p < 0.05; and 8.02 ± 4.31 days vs. 12.45 ± 5.14 days with t = 4.63 and p < 0.001). They did not show significant differences with regards to the complications and the incidences of cerebral palsy, hearing and visual impairments, and severe nervous damage (p > 0.05).

CONCLUSION

NO inhalation combined with HFOV significantly decreases the death rate of neonates with severe hypoxemia and reduces their mechanical ventilation and oxygen therapy time. It does not increase early adverse effects or affect long-term neurodevelopment.

Valley-polarized interlayer conduction of anisotropic Dirac fermions in SrMnBi2

We report the valley-selective interlayer conduction of SrMnBi(2) under in-plane magnetic fields. The c-axis resistivity of SrMnBi(2) shows clear angular magnetoresistance oscillations indicating coherent interlayer conduction. Strong fourfold variation of the coherent peak in the c-axis resistivity reveals that the contribution of each Dirac valley is significantly modulated by the in-plane field orientation. This originates from anisotropic Dirac Fermi surfaces with strong disparity in the momentum-dependent interlayer coupling. Furthermore, we found a signature of broken valley symmetry at high magnetic fields. These findings demonstrate that a quasi-two-dimensional anisotropic Dirac system can host a valley-polarized interlayer current through magnetic valley control.

An intrauterine catch-up growth regimen increases food intake and post-natal growth in rats

Nutritional conditions during the intrauterine stage are an important developmental programming factor that can affect the growth and metabolic status during foetal development and permanently alter the phenotypes of newborn offspring and adults. This study was performed to examine the effects of intrauterine catch-up growth (IUCG) on food intake, post-natal body growth and the metabolic status of offspring and growing rats. Control pregnant rats were fed ad libitum during the entire gestation period. For the IUCG regimen, pregnant rats were fed 50% of the food of the controls from pregnancy days 4 through 11 (8 days), followed by ad libitum feeding from pregnancy days 12 through parturition. The birth weight of offspring was not affected by the IUCG regimen. At weaning, offspring from each treatment group were assigned to two groups and given either a normal diet or high-fat diet (HFD) for 12 weeks until 103 days of age. In the normal diet group, the IUCG offspring showed a 9.0% increase (P < 0.05) in total food intake, were 11.2% heavier (p < 0.05) at 103 days of age and had an 11.0% greater (p < 0.05) daily weight gain compared with control offspring. The IUCG regimen did not affect body glucose and lipid metabolism. After exposure to the HFD, the IUCG regimen has not exacerbated metabolic disorders. In conclusion, our findings suggest that the IUCG nutritional regimen during pregnancy can increase the food intake and post-natal body growth of offspring without inducing metabolic disorders such as obesity and insulin resistance. The IUCG nutritional regimen might be used to improve the food intake and post-natal body growth of domestic animals.

Pharmacokinetic analysis of two different doses of duloxetine following oral administration in dogs

BACKGROUND

Duloxetine is a potent and balanced dual inhibitor of serotonin and norepinephrine reuptake that is being investigated for the treatment of depression and urinary incontinence. The purpose of this study was to investigate the pharmacokinetic properties of duloxetine in 20 beagle dogs following a single oral administration of a 30- or 60-mg enteric-coated pellet in a capsule (Cymbalta).

METHOD

Following the administration of 30 or 60 mg of Cymbalta to 20 beagle dogs, the plasma concentration of duloxetine was measured using LC-MS/MS. Pharmacokinetic parameters were analyzed using both noncompartmental and compartmental approaches.

RESULTS

The values of C max and AUC increased in proportion to the dose of duloxetine. The one compartment model with first-order absorption and a lag time was used successfully for pharmacokinetic analysis of duloxetine following a single oral administration of Cymbalta 30 mg or 60 mg.

CONCLUSIONS

The studies described here are the first to report the pharmacokinetics of oral duloxetine in dogs, and these findings provide important information for pharmaceutical formulation research of duloxetine using dogs.

An evidence-based approach for providing cautionary recommendations to sulfonamide-allergic patients and determining cross-reactivity among sulfonamide-containing medications

WHAT IS KNOWN AND OBJECTIVE

Prescribing sulfonamide-containing medications for patients with sulfonamide allergy continues to complicate medical decisions. We examined the cautionary recommendations in the approved drug monographs and primary literature, and formulated an evidence-based grading of cautionary recommendations for sulfonamide allergy and cross-reactivity among sulfonamide-containing medications.

METHODS

Drug monographs were collected from six countries and three drug compendia. Two reviewers independently extracted the data from the contraindication, warning and/or precaution sections of drug monographs. Evidence for cross-reactivity was examined in the primary literature and compared with drug monograph recommendations. Consequently, medications were categorized based on the strength of recommendation and level of evidence by consensus.

RESULTS AND DISCUSSION

We identified wide variability in cautionary recommendations ranging from no warning or precaution to contraindication among the sources reviewed. The recommendations were located mainly in the contraindication section of monographs for France (65·2%), United Kingdom (51·9%), Italy (50·0%), South Korea (43·5%), United States (38·2%) and Canada (37·0%), whereas in drug compendia, the recommendations were found in the precaution section for Martindale (51·4%) and Micromedex-Drugdex (33·3%), and contraindication and precaution section for the American Hospital Formulary Service Drug Information 2010 (30·8%). Evidence from the primary literature varied with recommendation included in drug monographs. Evidence-based categorization was carried out for 16 medications. Two sulfonamide-moiety-containing drugs were considered safe, six non-sulfonylarylamines required precaution, and eight medications from all three sulfonamide chemical classes were considered mostly unsafe.

WHAT IS NEW AND CONCLUSION

There are significant discrepancies in cautionary recommendations included in drug-labels and drug compendia. Statements concerning cross-reactive hypersensitivity with other sulfonamides generally suggest theoretical possibilities. The consensus evidence-based grading instrument developed may be useful for deriving cautionary recommendations for sulfonamide-allergic patients.

TGF-β1 and hypoxia-dependent expression of MKP-1 leads tumor resistance to death receptor-mediated cell death

Sporadic occurrence of transformed tumor cells is under the surveillance of the host immune system and such cells are effectively eliminated by immune-mediated cell death. During tumor progression, the antitumor effects of the tumor microenvironment are suppressed by diverse immunosuppressive mechanisms. In this research, we suggest novel immune evasion strategy of tumor cells through a transforming growth factor (TGF)-β1- and hypoxia-dependent mechanism. Experimental results showed that TGF-β1 and hypoxia induced mitogen-activated protein kinase phosphatase (MKP)-1 expression within 1 h, resulting in attenuation of c-Jun N-terminal kinase (JNK) phosphorylation and subsequent death receptor-mediated cell death. In addition, analysis of microarray data and immunostaining of MKP-1 in hepatocellular carcinoma (HCC) patient samples revealed that expression of MKP-1 is notably higher in tumors than in normal tissues, implying that MKP-1-dependent suppression of immune-mediated cell death takes place only in the tumor. To prove that MKP-1 can act as a mediator of immune escape by tumors, we determined whether chemo-resistance against several anticancer drugs could be overcome by knockdown of MKP-1. Cytotoxic assays showed that chemotherapy with siRNA targeting MKP-1 was significantly more effective than chemotherapy in the presence of MKP-1. Thus, we conclude that TGF-β1 and hypoxia ensure tumor cell survival and growth through expression of MKP-1.

Characterization and optimization of vascular endothelial growth factor(165) (rhVEGF(165)) expression in Escherichia coli

Vascular endothelial growth factors(165) (VEGF(165)) is the most potent and widely used pro-angiogenic factor. Here we determined optimal culture condition of recombinant human VEGF(165) (rhVEGF(165)) in Escherichia coli (E. coli). rhVEGF(165) expression was the highest in 0.25% of L-arabinose induction concentration, at 20 °C induction temperature, and for 5 h induction time under the control of araBAD promoter using pBADHisA vector. In biological activity test, rhVEGF(165) significantly increased the proliferative activity of CPAE cells (p<0.001) and upregulated the expressions of endothelial cell growth-related genes, such as platelet endothelial cell adhesion molecule (PECAM-1), endothelial-specific receptor tyrosine kinase (TEK), kinase insert domain protein receptor (KDR), and tyrosine kinase with immunoglobulin-like and EGF-like domains 1 (TIE1) in calf pulmonary artery endothelial (CPAE) cells.

Myocardial pharmacokinetics of ebastine, a substrate for cytochrome P450 2J, in rat isolated heart

BACKGROUND AND PURPOSE

It is well established that cytochrome P450 2J (CYP2J) enzymes are expressed preferentially in the heart, and that ebastine is a substrate for CYP2J, but it is not known whether ebastine is metabolized in myocardium. Therefore, we investigated its pharmacokinetics in the rat isolated perfused heart.

EXPERIMENTAL APPROACH

Rat isolated hearts were perfused in the recirculating mode with ebastine for 130 min. The concentrations of ebastine and its metabolites, hydroxyebastine and carebastine, were measured using liquid chromatography with a tandem mass spectrometry. The data were analysed by a compartmental model. The time course of negative inotropic response was linked to ebastine concentration to determine the concentration-effect relationship.

KEY RESULTS

Ebastine was metabolized to an intermediate compound, hydroxyebastine, which was subsequently further metabolized to carebastine. No desalkylebastine was found. The kinetics of the sequential metabolism of ebastine was well described by the compartmental model. The EC(50) of the negative inotropic effect of ebastine in rat isolated heart was much higher than free plasma concentrations in humans after clinical doses.

CONCLUSIONS AND IMPLICATIONS

The kinetics of ebastine conversion to carebastine via hydroxyebastine resembled that observed in human liver microsomes. The results may be of interest for functional characterization of CYP2J activity in rat heart.

Updated survival results of the randomized phase II study comparing cisplatin/capecitabine (CX) with epirubicin plus CX (ECX) in advanced gastric cancer (AGC)

46

Background: We previously reported results of a randomized study showing that CX is equally active to ECX in terms of progression-free survival (PFS) (Yun et al. Eur J Cancer. 2010). Here we report updated overall survival (OS) results with an additional 12 months' follow-up.

Methods: Ninety-one chemotherapy-naïve patients with histologically-confirmed, measurable AGC were randomized to receive CX (cisplatin 75 mg/m2 iv on day 1 and capecitabine 1,000 mg/m2 bid po on days 1-14, n=45) or ECX (epirubicin 50 mg/m2 plus CX, n=44) every 3 weeks. After CX or ECX had failed, second-line chemotherapy (SLC) was recommended for all patients if their performance status was preserved.

Results: Treatment duration was similar for both arms (4.4 for CX v 4.2 months for ECX). There was no relevant difference in the occurrence of overall grade 3 or 4 toxicities between the CX and ECX arms (80% v 78%, respectively; p=0.516). However, none in the CX and 12% in the ECX arm discontinued treatment because of toxicity. There were no significant differences in therapeutic efficacy between CX and ECX with respect to the response rate (38% v 37%, respectively), PFS (6.4 v 6.5 months), as well as OS (12.7 v 13.8 months; p=0.51). After failure, 60% of patients (26 CX and 28 ECX patients) received SLC. However, OS was not differed whether a patient was treated with SLC or not (13.1 v 11.2 months; p=0.94).

Conclusions: The present analysis confirms previous findings that both CX and ECX appear to be comparatively active as first-line chemotherapy for AGC. Furthermore, the role of SLC in AGC warrants further evaluation.

No significant financial relationships to disclose.

Clinicopathological correlation of beclin-1 expression in human colon cancer

464

Background: We investigated the expression of beclin-1 and bcl-2 in human colon cancer tissue by immunohistochemical analysis using a tissue microarray in relation to other prognostic factors.

Methods: Tissue samples from 78 cases of invasive colon cancer were used for the present study. A positive control for bcl-2 expression was small lymphocytes in the mantle zone. Immunohistochemical staining for beclin-1 and bcl-2 was evaluated according to intensity and proportion. The intensity score was determined as 0 (no staining), 1 (weak), 2 (moderate) and 3 (strong). The proportion score was determined as 1 (< 30% of tumor cells) and 2 (≥ 30% of tumor cells). The intensity score and proportion score were multiplied together for a total score. Total scores were as follows: 0-1 (negative) and 2-6 (positive).

Results: The normal colonic epithelium showed weak to no beclin-1 expression. Positive beclin-1 expression and positive bcl-2 expression of colon cancer cells was observed in 48 cases (61.5%) and 10 cases (12.8%), respectively. beclin-1 expression was significantly correlated with lymph node metastasis (p = 0.035) Bcl-2 expression in colon cancer cells showed no significant correlation with clinocopathologic factors studied. Beclin-1 expression was not correlated with bcl-2 expression in colon cancer cells (p = 0.348).

Conclusions: In conclusion, we have characterized the expression of beclin-1 in human colon cancer and the relationship with bcl-2 protein. Our results suggest that it seems reasonable to assume that beclin-1 might play a role in the development of colorectal cancer.

No significant financial relationships to disclose.

A retrospective study of first-line combination chemotherapy in advanced colorectal cancer: A Korean single-center experience

623

Background: Fluoropyrimidine-based combination chemotherapy, in combination with either oxaliplatin or irinotecan, have demonstrated efficacy and tolerability against advanced colorectal cancer (ACC).

Methods: Between Jan 2006 and Dec 2007, 478 ACC patients were treated with combination chemotherapy in first-line setting: 5-fluorouracil, folinic acid plus oxaliplatin (FOLFOX, n=172), 5-fluorouracil, folinic acid plus irinotecan (FOLFIRI, n=95), capecitabine plus oxaliplatin (XELOX, n=155), and capecitabine plus irinotecan (XELIRI, n=56). FOLFOX and FOLFIRI were repeated every 2 weeks, whereas XELOX and XELIRI were repeated every 3 weeks until disease progression or unacceptable toxicity occurred or until a patient chose to discontinue treatment.

Results: The median age was 58 years (range, 19-84 years) and the median chemotherapy duration for FOLFOX, FOLFIRI, XELOX and XELIRI were 4.9, 4.5, 5.7 and 5.4 months, respectively. Combination chemotherapy regimens were generally well tolerated. The estimated median PFS for all patients was 6.8 months (95% confidence interval, 6.3-7.3 months). No statistically significant difference in PFS was found each regimen used as first-line chemotherapy. Sixty-percent (n=290) of patients received second or further lines of therapy after failure.

Conclusions: Fluoropyrimidine-based combination chemotherapy regimens appear to be equally active and tolerable as first-line therapy for ACC.

No significant financial relationships to disclose.

Prognostic factors in patients with advanced hepatocellular carcinoma treated with sorafenib: A comparison with previously known prognostic models

323

Background: Sorafenib, a multiple-targeted tyrosine kinase inhibitor, is now the treatment of choice for systemic therapy of patients with advanced hepatocellular carcinoma (HCC). Herein we present the clinical characteristics and outcomes of patients with advanced HCC who were treated with sorafenib.

Methods: Data of 201 sorafenib-treated, metastatic HCC patients were collected from a single institution tumor registry. The primary and secondary endpoints were overall survival (OS) and failure-free survival (FFS).

Results: Chronic hepatitis B was the predominant cause of HCC (84%).Of 162 evaluable patients, four partial responses were recorded. With a median follow-up of 15.7 months, the median FFS and OS were 2.5 months (95% confidence interval [CI], 2.3-2.7 months) and 5.3 months (95% CI, 4.4-6.3 months), respectively. In multivariate analysis, the prognostic factors associated with FFS were the presence of ascites, portal venous thrombosis, serum alpha- fetoprotein (AFP) ≥400 ng/mL, albumin, bilirubin, tumor size and number, and performance status. Likewise, the presence of ascites, portal venous thrombosis, tumor size and number, performance status, and baseline levels of AFP, albumin and bilirubin were significantly related with OS. After adjusting for performance status, the Cancer of the Liver Italian Program (CLIP) scoring system and Okuda stages can better predict the hazard of failure or death than Child-Pugh classification.

Conclusions: Our results suggest that CLIP scores or Okuda stages, along with performance status, can be useful in stratifying patients with advanced HCC treated with sorafenib.

No significant financial relationships to disclose.

A phase I study of neoadjuvant chemoradiotherapy with S-1/oxaliplatin in patients with gastric cancer

51

Background: To determine the maximum tolerated dose (MTD) of concurrent radiotherapy with S-1 and oxaliplatin, and antitumor activity of the combination treatment in patients with gastric cancer.

Methods: This was a phase I, escalating multiple-dose tolerability trial. S-1 and oxaliplatin were administered concurrently with radiotherapy for 4 weeks before surgery. The dose escalation scheme is provided in the table below. S-1 was continuously administered during radiotherapy and oxaliplatin was administered weekly for 4 weeks during radiotherapy.

Results: From March 2009 to June 2010, twelve patients were entered at two dose levels. The most common dose-related grade 1 and 2 adverse events were nausea, vomiting, anorexia and abdominal pain. Two of six patients treated at level 1 developed DLT (disabling abdominal pain, stomach perforation). The dose of S-1/oxaliplatin was reduced to 30 mg/m2 bid and 40 mg/m2 (Level -1). There one DLT (vomiting and anorexia, grade 3) observed in the expanded cohort of 6 patients at Level -1. Among 12 patients, 1 patient demonstrated pathological CR after neoadjuvant chemoradiation therapy.

Conclusions: Neoadjuvant CCRT with S-1/oxaliplatin was well tolerated, at a dose 30 mg/m2 bid for S-1 and 40 mg/m2 for oxaliplatin that at which antitumor activity was seen. Phase II study is planned to investigate further the efficacy, tolerability and optimal dose.

[Table: see text]

No significant financial relationships to disclose.

Zero-bias anomalies in narrow tunnel junctions in the quantum Hall regime

We report on the study of cleaved-edge-overgrown line junctions with a serendipitously created narrow opening in an otherwise thin, precise line barrier. Two sets of zero-bias anomalies are observed with an enhanced conductance for filling factors ν>1 and a strongly suppressed conductance for ν<1. A transition between the two behaviors is found near ν≈1. The zero-bias anomaly (ZBA) line shapes find explanation in Luttinger liquid models of tunneling between quantum Hall edge states. The ZBA for ν<1 occurs from strong backscattering induced by suppression of quasiparticle tunneling between the edge channels for the n=0 Landau levels. The ZBA for ν>1 arises from weak tunneling of quasiparticles between the n=1 edge channels.

A modified technique improved histology similarity to human intracranial aneurysm in rabbit aneurysm model

Persistent undigested elastic membranes and collagen in the tunic media of rabbit elastase-induced aneurysm models lowered their histology similarity to human intracranial aneurysm. Our purpose was to make good the deficiency. Ten New Zealand white rabbits were divided into three groups: six rabbit in two groups for evaluating the difference in various treatments, and four rabbits for long-term observation. We inflated and occluded the right common carotid artery (CCA) by an endovascular technique. The first group of three rabbits was only given 200u elastase in the proximal segment of right CCA; the second group was given 100u elastase and 1.5mg collagenase, then the right CCA was ligated. The first and second groups were studied by magnetic resonance angiography (MRA), sacrificed at three weeks after aneurysm creation, their histology results were obtained and compared with human aneurysm. The third group underwent the same procedure as the second group only for three months of observation with enhanced MRA. Saccular aneurysms formed in all rabbits. Degeneration of the extracellular matrix and atrophy of smooth muscular cells in tunic media were more apparent in the second group. The third group remained stable for more three months. Two modifications included inflating the right CCA with a balloon and adding collagenase incubation can promote an aneurysm model more histologically similar to human aneurysm. In addition the improved aneurysm model remains stability for a long time.

Development of a population-based microsimulation model of osteoarthritis in Canada

OBJECTIVES

The purpose of the study was to develop a population-based simulation model of osteoarthritis (OA) in Canada that can be used to quantify the future health and economic burden of OA under a range of scenarios for changes in the OA risk factors and treatments. In this article we describe the overall structure of the model, sources of data, derivation of key input parameters for the epidemiological component of the model, and preliminary validation studies.

DESIGN

We used the Population Health Model (POHEM) platform to develop a stochastic continuous-time microsimulation model of physician-diagnosed OA. Incidence rates were calibrated to agree with administrative data for the province of British Columbia, Canada. The effect of obesity on OA incidence and the impact of OA on health-related quality of life (HRQL) were modeled using Canadian national surveys.

RESULTS

Incidence rates of OA in the model increase approximately linearly with age in both sexes between the ages of 50 and 80 and plateau in the very old. In those aged 50+, the rates are substantially higher in women. At baseline, the prevalence of OA is 11.5%, 13.6% in women and 9.3% in men. The OA hazard ratios for obesity are 2.0 in women and 1.7 in men. The effect of OA diagnosis on HRQL, as measured by the Health Utilities Index Mark 3 (HUI3), is to reduce it by 0.10 in women and 0.14 in men.

CONCLUSIONS

We describe the development of the first population-based microsimulation model of OA. Strengths of this model include the use of large population databases to derive the key parameters and the application of modern microsimulation technology. Limitations of the model reflect the limitations of administrative and survey data and gaps in the epidemiological and HRQL literature.

Definitive chemoradiation therapy with capecitabine in locally advanced pancreatic cancer

e15558

Background: We evaluated safety and efficacy of concurrent chemoradiotherapy (CCRT) with capecitabine in patients with locally advanced pancreatic cancer (LAPC). We also tried to devise a prognostic model for LAPC undergoing definitive CCRT. Methods: Between January 2004 and January 2008, 39 patients with LAPC treated with capecitabine CCRT were reviewed. Capecitabine was administered at 850 mg/m2 bid every day for 5 weeks. Radiotherapy was given 5 days per week, at 1.8 Gy fractions, over the 5 weeks. Results: Thirty seven (94.8%) patients completed CCRT, and 2 patients removed during the treatment for toxicity issues. Of the 36 evaluable patients, 15 (41.7 %) patients achieved partial response, and 13 (36.1 %) had a stable disease with 77.8% of disease control rate. Among the 28 patients who had achieved disease control after CCRT, 8 patients (21.6 %) received gemcitabine-based post-CCRT chemotherapy without dose reduction or delay. With median 1.8 years of follow- up, the overall survival was 14.3 months (95% confidence interval [CI]; 10.6–17.9 months). Median progression free survival was 11.1 (95% CI 7.2–15.1) for all patients, and 7.9 months (95% CI 6.6–9.2) for those not received post-CCRT chemotherapy. No patient had grade 4 hematologic or non-hematologic toxicity. Eight patients (21.6%) had severe grade 3 toxicities, 7 (18.9%) with gastrointestinal toxicity and 1 (2.7%) with hematologic toxicity. Prognostic factors for survival were serum albumin (P=0.014; relative risk [RR], 3.4; 95% CI, 1.4, 8.6), and adjuvant gemcitabine treatment (P = 0.005; RR, 3.5; 95% CI, 1.2, 10.6). The prognostic grouping resulted in three groups with significantly different prognosis: group 1 (0 adverse factor; n=8; 1-year survival, 87.5%), group 2 (1 adverse factor; n=23; 1-year survival, 52.9%) and group 3 (2 adverse factors; n=8; 1-year survival, 25.0%). Conclusions: Combined therapy with capecitabine CCRT was well tolerated. Capecitabine seems to be a promising regimen in the treatment of LAPC, in terms of response, survival, and tolerable adverse effects.

No significant financial relationships to disclose.

Leptomeningeal carcinomatosis of gastric cancer: Multicenter retrospective analysis of 54 cases

e15658

Background: Leptomeningeal carcinomatosis occurs in approximately 5% of patients with cancer. The most common cancers involving the leptomeninges are breast and lung cancer. However, gastric adenocarcinoma has been rarely reported with leptomeningeal carcinomatosis (LMC). Methods: We analyzed 54 cases of cytological confirmed gastric LMC at 4 institutions from 1994 to 2007. Results: Male to female ratio was 1.5:1. Median age of these patients was 49 years. The majority of patients had advanced disease at the initial diagnosis of gastric cancer. The clinical or pathologic TNM stages of the primary gastric cancer were IV in 38 patients (70%). The median interval from the diagnosis of the primary malignancy to the diagnosis of LMC was 6.3 months (range, 0 - 73.1 months). Of the initial endoscopic finding available 45 patients, Bormann type III and IV were 23 (51%) and 15 (33%) patients, respectively. Headache (85%) and nausea/vomiting (58%) were most common presenting symptoms of LMC. The intrathecal (IT) chemotherapy was administered to 36 patients - mainly with methotraxate alone (59%) or combination with ara- C/hydrocortisone (41%). Median IT treatment number was 7 (range, 1–18). Concomitant radiotherapy or chemotherapy was done in 25 patients and 10 patients, respectively. 17 patients (46%) were achieved cytological negative conversion. Median OS duration from diagnosis of LMC was 6.7 weeks (95% CI; 4.3–9.1 weeks). Clinically, initial advanced stage was predictive value of poor prognosis (P=0.009). But, Cytology negative conversion was predictive value of relatively longer survival duration (P=0.005). And, not only IT chemotherapy but also intravenous chemotherapy had been shown improvement of survival duration (P=0.010, P=0.005, respectively). Conclusions: Although gastric LMC has dismal prognosis, IT and IV chemotherapy could be help to extend survival duration of gastric LMC.

No significant financial relationships to disclose.

Phase III trial of adjuvant capecitabine/cisplatin (XP) versus capecitabine/cisplatin/RT (XPRT) in resected gastric cancer with D2 nodal dissection (ARTIST trial): Safety analysis

4537

Background: Although the adjuvant chemoradiation therapy has gained popularity and has become the standard of care in patients with resected gastric cancer in U.S., the role of chemoradiation therapy after extended D2 dissection has been questioned. We conducted a phase III trial to compare capecitabine/cisplatin (XP) vs XP + radiotherapy (RT) in curatively D2 resected gastric cancer patients in terms of disease free survival and overall survival. Methods: Eligibility criteria were as follows: stage Ib (T1N1, T2bN0) - IV (M1 excluded), curatively ≥ D2 resected gastric adenocarcinoma. XP only: X 2,000 mg/m2/d D1∼14, CDDP 60 mg/m2 D1 repeated every 3 weeks, 6 cycles; XP + RT: X 2,000 mg/m2/d D1∼14, CDDP 60 mg/m2 D1 x 2 cycles ⋄ RT 45 Gy (25 fractions) + X 1,650 mg/m2/d during RT ⋄ X 2,000 mg/m2/d D1∼14, CDDP 60 mg/m2 D1 x 2 cycles. The primary endpoint is 3-year disease-free survival. Results: From October 2004 to April 2008, 458 patients (XP arm: 228 patients; XP/RT arm: 230 patients) were enrolled. In XP arm, 172 (75%) of 228 enrolled patients completed 6 cycles of chemotherapy. In XP + RT arm, 188 (82%) of 230 patients completed the full course of XP 2 cycles - X + RT - XP 2 cycles. Conclusions: Safety and feasibility analysis of the two arms will be reported at the meeting.

No significant financial relationships to disclose.

A phase II study of imatinib mesylate as adjuvant treatment for curatively resected high-risk localized gastrointestinal stromal tumors

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Background: In our previous study, the presence of c-kit mutation as well as tumor size and mitotic count was an independent poor risk factor for relapse after curative resection of primary localized GIST. The patients with all the 3 poor risk factors had only 30% of 2 year relapse free survival rate (RFSR). (Kim, et al. Clin Cancer Res, 2004) It is also well known that c-kit exon 11 mutant GISTs respond better to imatinib treatment than the other mutant or wild type GISTs. Therefore, the patients who have primary localized GISTs with large size, high mitotic count, and c-kit exon 11 mutation may be the best candidate of adjuvant imatinib treatment. In this phase II study, we have evaluated the efficacy and safety of adjuvant imatinib for this patient group. Methods: Patients who underwent complete resection of a primary GIST with 1) c-kit exon 11 mutation, and 2) ≥10 mitoses/50 HPF, or tumor size ≥10 cm, or ≥5 mitoses/50 HPF and tumor size ≥5 cm were eligible. Patients received imatinib 400mg p.o. daily until recurrence of disease, intolerable toxicities, or for 2 years. The primary end point was relapse-free survival (RFS). Results: A total of 47 patients from 4 centers in Korea were enrolled. The median age was 57.0 years. Stomach was the most common primary site (n=31). Median primary tumor size was 7.5cm and median mitoses index was 12/50 HPF. With a median follow-up of 26.9 months, the median RFS and overall survival (OS) have not yet been reached. RFSR was 97.7% at 1-year and 92.7% at 2-years. Six relapses (12.8%) were documented among the 47 patients. The treatments were generally well tolerated. Grade 3–4 toxicities included neutropenia 27.7%, rash 8.5%, constipation 4.3%, anorexia 2.1%, vomiting 2.1%, and pruritis 2.1%. There were no episode of febrile neutropenia and treatment-related death. Conclusions: Postoperative adjuvant imatinib for 2 years were safe and could prolong the RFS in patients with high-risk of recurrence following complete surgical resection of the primary GIST. However, it remains unknown if this benefit in RFS can be translated into OS benefit. So, further follow-up is needed with comparison of OS with historical controls who could be use imatinib after recurrence.

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The role of oophorectomy for colon cancer with ovarian metastasis

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Background: A recent study demonstrated that colorectal cancer with ovarian metastases were less responsive to chemotherapy compared to extraovarian metastases. Hence, the ovary may actually represent a “sanctuary” for metastatic cells from CRC. The aim of the study was to investigate the impact of oophorectomy on survival of colorectal cancer patients with ovarian metastasis. Methods: Between 1996 and 2008, 83 colorectal cancer patients underwent oophorectomy. For the historical control, 47 colorectal cancer patients without oophorectomy were included in the analysis. Survival and its associated factors were analyzed using Kaplan-Meier method, log-rank test and Cox-regression analysis. Results: The median age was younger (48 years) in the oophorectomy group when compared to the historical control (54 years) (P =.012). The proportion of synchronous metastasis was higher in the oophorectomy than the control group (57% vs 30%, respectively; P=.003). After a median follow-up duration of 60.8 months (range, 7.4 - 169.7 months), the median OS was significantly longer in the oophorectomy group (28.1 vs 21.2 months, oophorectomy vs non-oophoreectomy; P=.038). For ovary-specific survival (date of ovarian metastasis diagnosis to death), colorectal cancer patients with oophorectomy showed significantly favorable survival than the control group (20.8 vs 10.9 months, respectively; P<.001). At univariate analyses, no oophorectomy (P=.038), bilaterality of ovarian metastasis (P=0.032), the presence of extraovarian metastasis (P<0.001), elevated CEA (p<0.001), poor performance status (p=0.001), no palliative chemotherapy(p=0.001), no primary disease resection(p=0.005) were identified as significantly poor prognostic factors for overall survival. The no oophorectomy, no chemotherapy, extraovarian metastasis, elevated CEA, poor performance status retained statistical significance at multivariate level. (p=0.003, p=0.004, p=0.005, p=0.015, p=0.029, respectively). Conclusions: Based on this retrospective analysis, the oophorectomy significantly prolonged survival in colorectal cancer patients with ovarian metastases. A potential role of oophorectomy in the management of colorectal cancer should be prospectively studied.

No significant financial relationships to disclose.

Unusual Hall effect anomaly in MnSi under pressure

We report the observation of a highly unusual Hall current in the helical magnet MnSi in an applied pressure P=6-12 kbars. The Hall conductivity displays a distinctive stepwise field profile quite unlike any other Hall response observed in solids. We identify the origin of this Hall current with the effective real-space magnetic field due to chiral spin textures, which may be a precursor of the partial-order state at P>14.6 kbar. We discuss evidence favoring the chiral spin mechanism for the origin of the observed Hall anomaly.

An efficient rHSV-based complementation system for the production of multiple rAAV vector serotypes

Recombinant herpes simplex virus type 1 (rHSV)-assisted recombinant adeno-associated virus (rAAV) vector production provides a highly efficient and scalable method for manufacture of clinical grade rAAV vectors. Here, we present an rHSV co-infection system for rAAV production, which uses two ICP27-deficient rHSV constructs, one bearing the rep2 and cap (1, 2 or 9) genes of rAAV, and the second bearing an AAV2 ITR-gene of interest (GOI) cassette. The optimum rAAV production parameters were defined by producing rAAV2/GFP in HEK293 cells, yielding greater than 9000 infectious particles per cell with a 14:1 DNase resistance particle to infectious particle (DRP/ip) ratio. The optimized co-infection parameters were then used to generate large-scale stocks of rAAV1/AAT, which encode the human alpha-1-antitrypsin (hAAT) protein, and purified by column chromatography. The purified vector was extensively characterized by rAAV- and rHSV-specific assays and compared to transfection-made vector for in vivo efficacy in mice through intramuscular injection. The co-infection method was also used to produce rAAV9/AAT for comparison to rAAV1/AAT in vivo. Intramuscular administration of 1 x 10(11) DRP per animal of rHSV-produced rAAV1/AAT and rAAV9/AAT resulted in hAAT protein expression of 5.4 x 10(4) and 9.4 x 10(5) ng ml(-1) serum respectively, the latter being clinically relevant.

Stereoselective inhibition of cytochrome P450 forms by lansoprazole and omeprazolein vitro

The stereoselectivity of the inhibitory interaction potential of lansoprazole and omeprazole isomers on six human cytochrome P450 forms was evaluated using human liver microsomes. Lansoprazole enantiomers showed stereoselective inhibition of CYP2C9-catalysed tolbutamide 4-methylhydroxylation, CYP2C19-catalysed S-mephenytoin 4'-hydroxylation, CYP2D6-catalysed dextromethorphan O-demethylation, CYP2E1-catalysed chlorzoxazone 6-hydroxylation and CYP3A4-catalysed midazolam 1-hydroxylation, whereas omeprazole only inhibited CYP2C19 stereoselectively. Of the P450 forms tested, CYP2C19-catalysed S-mephenytoin 4'-hydroxylation was extensively inhibited by both the lansoprazole and omeprazole enantiomers in a competitive and stereoselective manner; the S-enantiomers of both drugs inhibited the hydroxylation more than the R-enantiomers. The estimated K(i) values determined for CYP2C19-catalysed S-mephenytoin 4'-hydroxylation were 0.6, 6.1, 3.4 and 5.7 microM for S-lansoprazole, R-lansoprazole, S-omeprazole and R-omeprazole, respectively. The results indicate that although both lansoprazole and omeprazole are strong inhibitors of CYP2C19, the inhibition of CYP2C19 by lansoprazole is highly stereoselective, whereas the inhibition by omeprazole is less stereoselective. In addition, S-lansoprazole, the most potent CYP2C19 inhibitor, is not a good CYP2C19-selective inhibitor owing to its inhibition of other P450 forms.

Dietary salt does not influence the disposition of verapamil enantiomers in relation to efflux transporter ABCB1 genetic polymorphism in healthy Korean subjects

To evaluate the effects of dietary salt on the stereoselective disposition of verapamil enantiomers in relation to the transporter ABCB1 2677GG/3435CC and 2677TT/3435TT haplotypes, ten healthy subjects were asked to take diets of three different salt levels for 7 days in a randomized, three-way crossover manner. The plasma concentrations of verapamil and norverapamil enantiomers were determined after a single oral dose of 240 mg verapamil on the last day of each phase. Pharmacokinetic parameters were calculated by non-compartmental analysis techniques and compared among the three different dietary salt phases. Compared with the medium salt diet, the high and low salt diets had no significant effect on the disposition of verapamil enantiomers. Moreover, the ABCB1 haplotypes did not alter the impact of dietary salt, although ABCB1 2677TT/3435TT subjects had slightly, but not significantly, higher C(max) and area under the curve (AUC) and lower T(max) for the verapamil enantiomers than did 2677GG/3435CC subjects in each salt phase.