Food image-induced brain activation is not diminished by insulin infusion

Background/Objective

The obesity epidemic appears to be driven in large part by our modern environment inundated by food cues, which may influence our desire to eat. While insulin decreases food intake in both animals and humans, the effect of insulin on motivation for food in the presence of food cues is not known. Therefore, the aim of this study was to evaluate the effect of an intravenous insulin infusion on the brain response to visual food cues, hunger and food craving in non-obese human subjects.

Subjects/Methods

Thirty-four right-handed healthy non-obese subjects (19F/15M, age: 29±8 yrs.; BMI: 23.1±2.1 kg/m2) were divided in two groups matched by age, and BMI: the Insulin Group (18 subjects) underwent a hyperinsulinemic-euglycemic-clamp, and the control group (16 subjects) received an intravenous saline infusion, while viewing high and low-calorie food and non-food pictures during a functional MRI scan. Motivation for food was determined via analogue scales for hunger, wanting and liking ratings.

Results

Food images induced brain responses in the hypothalamus, striatum, amygdala, insula, ventromedial prefrontal cortex (PFC), dorsolateral PFC, and occipital lobe (whole brain correction, P<0.05). Wanting (P<0.001) and liking (P<0.001) ratings were significantly higher for the food than the non-food images, but not different between insulin and saline infusion groups. Hunger ratings increased throughout the MRI scan and correlated with preference for high-calorie food pictures (r=0.70; P<0.001). However neither brain activity nor food craving were affected by hyperinsulinemia or hormonal status (leptin and ghrelin levels) (P=NS).

Conclusion

Our data demonstrate that visual food cues induce a strong response in motivation/reward and cognitive-executive control brain regions in non-obese subjects, but that these responses are not diminished by hyperinsulinemia per se. These findings suggest that our modern food cue saturated environment may be sufficient to overpower homeostatic hormonal signals, and thus contribute to the current obesity epidemic.

A phase II study of axitinib in advanced neuroendocrine tumors

Neuroendocrine tumors (NETs) are highly vascular neoplasms overexpressing vascular endothelial growth factor (VEGF) as well as VEGF receptors (VEGFR). Axitinib is a potent, selective inhibitor of VEGFR-1, -2 and -3, currently approved for the treatment of advanced renal cell carcinoma. We performed an open-label, two-stage design, phase II trial of axitinib 5mg twice daily in patients with progressive unresectable/metastatic low-to-intermediate grade carcinoid tumors. The primary end points were progression-free survival (PFS) and 12-month PFS rate. The secondary end points included time to treatment failure (TTF), overall survival (OS), overall radiographic response rate (ORR), biochemical response rate and safety. A total of 30 patients were enrolled and assessable for toxicity; 22 patients were assessable for response. After a median follow-up of 29months, we observed a median PFS of 26.7months (95% CI, 11.4-35.1), with a 12-month PFS rate of 74.5% (±10.2). The median OS was 45.3 months (95% CI, 24.4-45.3), and the median TTF was 9.6months (95% CI, 5.5-12). The best radiographic response was partial response (PR) in 1/30 (3%) and stable disease (SD) in 21/30 patients (70%); 8/30 patients (27%) were unevaluable due to early withdrawal due to toxicity. Hypertension was the most common toxicity that developed in 27 patients (90%). Grade 3/4 hypertension was recorded in 19 patients (63%), leading to treatment discontinuation in six patients (20%). Although axitinib appears to have an inhibitory effect on tumor growth in patients with advanced, progressive carcinoid tumors, the high rate of grade 3/4 hypertension may represent a potential impediment to its use in unselected patients.

A phase I trial of panobinostat and epirubicin in solid tumors with a dose expansion in patients with sarcoma

BACKGROUND

Treatment options for sarcoma are limited. Histone deacetylase inhibitors increase the efficacy of topoisomerase II inhibitors by promoting access to chromatin and by down-regulating DNA repair. Thus, combined panobinostat and epirubicin therapy was evaluated to treat refractory sarcoma.

PATIENTS AND METHODS

Patients with advanced solid tumors were enrolled in a 3 + 3 dose-escalation phase I trial of panobinostat given on days 1, 3, and 5 followed by 75 mg/m(2) of epirubicin on day 5 in 21-day cycles, with a dose expansion at maximum tolerated dose (MTD) in 20 sarcoma patients. Peripheral blood mononucleocyte histone acetylation was also evaluated.

RESULTS

Forty patients received 20-60 mg panobinostat. Dose-limiting toxicities included thrombocytopenia, febrile neutropenia, and fatigue at 60 mg, defining a panobinostat MTD at 50 mg. Four responses were seen in 37 assessable patients, all after progression on prior topoisomerase II inhibitors. For those with sarcoma, 12 of 20 derived clinical benefit (1 partial response and 11 stable disease, median overall survival 8.3 months), including 8 of 14 previously progressed on topoisomerase II therapy. Treatment benefits correlated with increased histone acetylation and decreased neutrophil count on day 5.

CONCLUSIONS

Panobinostat and epirubicin treatment is well tolerated and may reverse anthracycline resistance. Changes in histone acetylation and associated decrease in neutrophil count correlated with clinical benefit and warrant investigation as predictive biomarkers.

CLINICAL TRIAL

This trial is registered at www.Clinicaltrials.gov, Identifier: NCT00878904.

Predisposition to and effects of methamphetamine use on the adolescent brain

Adolescence is a period of heightened vulnerability both to addictive behaviors and drug-induced brain damage. Yet, only limited information exists on the brain mechanisms underlying these adolescent-specific characteristics. Moreover, distinctions in brain correlates between predisposition to drug use and effects of drugs in adolescents are unclear. Using cortical thickness and diffusion tensor image analyses, we found greater and more widespread gray and white matter alterations, particularly affecting the frontostriatal system, in adolescent methamphetamine (MA) users compared with adult users. Among adolescent-specific gray matter alterations related to MA use, smaller cortical thickness in the orbitofrontal cortex was associated with family history of drug use. Our findings highlight that the adolescent brain, which undergoes active myelination and maturation, is more vulnerable to MA-related alterations than the adult brain. Furthermore, MA-use-related executive dysfunction was greater in adolescent MA users than in adult users. These findings may provide explanation for the severe behavioral complications and relapses that are common in adolescent-onset drug addiction. Additionally, these results may provide insights into distinguishing the neural mechanisms that underlie the predisposition to drug addiction from effects of drugs in adolescents.

Decreased efficacy of drugs targeting the vascular endothelial growth factor pathway by the epigenetic silencing of FLT1 in renal cancer cells

BACKGROUND

The vascular endothelial growth factor (VEGF)-VEGF receptor (VEGFR) signaling pathway is involved in cancer-related biological functions and is a therapeutic target in cancer. However, the influence of epigenetic regulation of VEGF-VEGFR signaling-related genes remains unclear. Here, we evaluated the effects of FLT1 and KDR promoter hypermethylation combined with drugs targeting VEGF-VEGFR signaling on cancer-related phenotypes in renal cancer cells (RCCs) and examined changes in FLT1 and KDR promoter hypermethylation in tissues from patients with renal cancer.

RESULTS

In vitro experiments were performed to evaluate the effects of beavacizumab (an anti-VEGF antibody), an anti-FLT1 peptide, an anti-KDR antibody, and the VEGFR tyrosine kinase inhibitors (TKIs) sunitinib and axitinib in 13 RCC lines with different levels of FLT1 and/or KDR promoter methylation and in 2 FLT1 or KDR in vitro knockdown models. The synergistic effects of sunitinib and axitinib treatment were also evaluated in four RCC lines having different levels of FLT1 and/or KDR methylation. In our in vitro experiments, bevacizumab and an anti-KDR antibody did not affect the proliferation of RCCs having FLT1 and/or KDR hypermethylation. In contrast, in RCCs with FLT1 hypermethylation, proliferation inhibition was counteracted by treatment with an anti-FLT1 peptide and both VEGF-TKIs (sunitinib and axitinib). Demethylation with sunitinib or axitinib synergistically increased proliferation inhibition in the RCCs exhibiting FLT1 hypermethylation. Using in vitro FLT1 or KDR knockdown models, decreased proliferation inhibition following anti-FLT1 peptide, sunitinib, and axitinib treatment was observed only in FLT1-knockdown cells. In patients with renal cancer who received sunitinib, FLT1 promoter methylation was higher in renal cancer tissues from eight nonresponders (stable or progressive disease assessed by the Response Evaluation Criteria in Solid Tumors) than in cancer tissues from five responders (complete response or partial response).

CONCLUSIONS

The present data showed that hypermethylated FLT1 was important for the efficacy of anti-VEGF/VEGFR drugs targeting FLT1 or intracellular VEGFR signaling. FLT1 hypermethylation causing alterations of FLT1 function could serve as a useful biomarker for predicting changes in FLT1 status in RCCs.

Growth of optical-quality anthracene crystals doped with dibenzoterrylene for controlled single photon production

Dibenzoterrylene (DBT) molecules within a crystalline anthracene matrix show promise as quantum emitters for controlled, single photon production. We present the design and construction of a chamber in which we reproducibly grow doped anthracene crystals of optical quality that are several mm across and a few μm thick. We demonstrate control of the DBT concentration over the range 6-300 parts per trillion and show that these DBT molecules are stable single-photon emitters. We interpret our data with a simple model that provides some information on the vapour pressure of DBT.

The combination of axitinib followed by paclitaxel/carboplatin yields extended survival in advanced BRAF wild-type melanoma: results of a clinical/correlative prospective phase II clinical trial

BACKGROUND

Simultaneous chemotherapy with vascular endothelial growth factor (VEGF) inhibition has not shown additional benefit over chemotherapy alone in advanced melanoma. We tested administration of the potent VEGF inhibitor axitinib followed by paclitaxel/carboplatin to determine whether enhanced tumour proliferation during axitinib withdrawal leads to sustained chemosensitivity.

METHODS

We conducted a prospective phase II trial in metastatic melanoma patients with ECOG performance status 0-1 and normal organ function. Axitinib 5 mg PO b.i.d. was taken on days 1-14 of each 21-day treatment cycle, and carboplatin (AUC=5) with paclitaxel (175 mg m(-2)) was administered on day 1 starting with cycle 2. 3'-Deoxy-3'-(18)F-fluorothymidine ((18)F-FLT)-PET scans were performed in five patients to assess tumour proliferation on days 1, 14, 17, and 20 of cycle 1. Molecular profiling for BRAF was performed for all patients with cutaneous, acral, or mucosal melanoma.

RESULTS

The treatment was well tolerated. The most common grade 3 AEs were hypertension, neutropenia, and anaemia. Grade 4 non-haematologic AEs were not observed. Four of five patients completing (18)F-FLT-PET scans showed increases (23-92%) in SUV values during the axitinib holiday. Of 36 evaluable patients, there were 8 confirmed PRs by Response Evaluation Criteria in Solid Tumors. Overall, 20 patients had SD and 8 had PD as the best response. The median PFS was 8.7 months and the median overall survival was 14.0 months. Five BRAF(V600E/K) patients had significantly worse PFS than patients without these mutations.

CONCLUSIONS

Axitinib followed by carboplatin and paclitaxel was well tolerated and effective in BRAF wild-type metastatic melanoma. 3'-Deoxy-3'-(18)F-fluorothymidine-PET scans showed increased proliferation during axitinib withdrawal.

Electron-boson spectral density of LiFeAs obtained from optical data

We analyze existing optical data in the superconducting state of LiFeAs at T = 4 K, to recover its electron-boson spectral density. A maximum entropy technique is employed to extract the spectral density I(2)χ(ω) from the optical scattering rate. Care is taken to properly account for elastic impurity scattering which can importantly affect the optics in an s-wave superconductor, but does not eliminate the boson structure. We find a robust peak in I(2)χ(ω) centered about Ω(R) ≅ 8.0 meV or 5.3 k(B)Tc (with Tc = 17.6 K). Its position in energy agrees well with a similar structure seen in scanning tunneling spectroscopy (STS). There is also a peak in the inelastic neutron scattering (INS) data at this same energy. This peak is found to persist in the normal state at T = 23 K. There is evidence that the superconducting gap is anisotropic as was also found in low temperature angular resolved photoemission (ARPES) data.

Delayed hematopoietic recovery after auto-SCT in patients receiving arsenic trioxide-based therapy for acute promyelocytic leukemia: a multi-center analysis

A potential link between arsenic (ATO)-based therapy and delayed hematopoietic recovery after autologous hematopoietic SCT (HSCT) for acute promyelocytic leukemia (APL) has previously been reported. We retrospectively reviewed the clinical histories of 58 patients undergoing autologous HSCT for APL at 21 institutions in the United States and Japan. Thirty-three (56%) of the patients received ATO-based therapy prior to stem cell collection. Delayed neutrophil engraftment occurred in 10 patients (17%): 9 of the 10 patients (90%) received prior ATO (representing 27% of all ATO-treated patients), compared with 1 of the 10 patients (10%) not previously treated with ATO (representing 4% of all ATO-naïve patients; P<0.001). Compared with ATO-naïve patients, ATO-treated patients experienced significantly longer times to ANC recovery (median 12 days vs 9 days, P<0.001). In multivariate analysis, the only significant independent predictor of delayed neutrophil engraftment was prior treatment with ATO (hazard ratio 4.87; P<0.001). Of the available stem cell aliquots from APL patients, the median viable post-thaw CD34+ cell recovery was significantly lower than that of cryopreserved autologous stem cell products from patients with non-APL AML. Our findings suggest that ATO exposure prior to CD34+ cell harvest has deleterious effects on hematopoietic recovery after autologous HSCT.

Single dipole evanescently coupled to a multimode waveguide

We consider a single dipole evanescently coupled to a cylindrical multimode waveguide. The emission rate into the waveguide is calculated as a function of the waveguide diameter and the dipole orientations, and the result is confirmed by finite-difference-time-domain simulations. We show that as the guide radius increases, the coupling to a given mode decreases but new decay channels to higher order modes open up to increase the density of states. This study gives insight for designing waveguide-based single photon sources that exploit superposition of transverse modes.

Physical activity and its related motivational attributes in adolescents with different BMI

BACKGROUND

A number of obesity studies have been focused on identifying the relationships between socioeconomic status and physical activity involvement. In behavioral medicine, the limited data are available on obese people's physical activity and its related psychological predictors based on psychological theories.

PURPOSE

To identify the differences in physical activity and its related motivational attributes among normal weight, overweight, and obese adolescents and to find the effect of body mass index (BMI) and the Self-Determination Theory (SDT) constructs in predicting physical activity.

METHOD

One thousand seventy-one students ranging from seventh to ninth grades were randomly selected from three junior high schools in Seoul (359 normal weight students, 468 overweight students, and 244 obese students). A Korean version of Behavioral Regulation in Exercise Questionnaire-2 and Leisure Time Exercise Questionnaire were applied to measure the participants' motivational attributes and physical activity.

RESULTS

Overweight and obese adolescents showed higher scores on amotivation and externally motivated regulations for physical activity than their normal weight counterparts. Internal regulation was more significant for physical activity in normal weight adolescent. However, there was no difference in physical activity among the three groups. Additionally, the findings identified that BMI and the SDT constructs were significant to explain physical activity.

CONCLUSION

This study offers fundamental knowledge in gaining a clearer understanding of the types of motivation most likely to contribute to the initiation and promotion of physical activity in overweight and obese adolescents.

Deriving the electron-phonon spectral density of MgB2 from optical data, using maximum entropy techniques

We use maximum entropy techniques to extract an electron-phonon density from optical data for the normal state at T = 45 K of MgB2. Limiting the analysis to a range of phonon energies below 110 meV, which is sufficient for capturing all phonon structures, we find a spectral function that is in good agreement with that calculated for the quasi-two-dimensional σ-band. Extending the analysis to higher energies, up to 160 meV, we find no evidence for any additional contributions to the fluctuation spectrum, but find that the data can only be understood if the density of states is taken to decrease with increasing energy.

Abstract P3-14-12: Risk factors for local regional recurrence in patients undergoing breast conserving surgery following neoadjuvant chemotherapy and validation of the MD Anderson prognostic index

Background: Breast conserving surgery (BCS) is a primary goal of neoadjuvant chemotherapy (NAC) in patients with locally advanced breast cancer, especially with recent improvements in tumor response. Patient selection for BCS following NAC may be different than classic local regional recurrence (LRR) risk factors. Here we investigate risk factors for LRR and attempt to validate the MD Anderson Prognostic Index (MDAPI) for LRR in a single institution series.

Methods: Data were analyzed for 178 consecutive patients treated at one institution who underwent NAC followed by BCS and whole breast radiotherapy between the years 1999 and 2011. Using univariate and multivariate analysis, multiple clinicopathologic factors were investigated, as well as the subgroups of the MDAPI. Chi-square tests were used to compare the LRR-free survival rates between subgroups.

Results: The median follow-up was 70.33 months and the 5-year LRR-free survival was 93.18%. Multivariate analysis demonstrated that clinical stage and pathologic stage were both statistically significant for LRR-free survival, while pattern of residual disease was of borderline statistical significance. The MDAPI was not significantly associated with LRR-free survival (MDAPI low 93.80%, Intermediate 88.23%, High 88.89%).

Five-Year Local Regional Recurrence -Free Survival According to Clinicopathologic Factors # Patients5yr LRR-Free SurvivalPathologic Stage p = 0.03301580.0%14292.5%27692.5%3994.6%pCR38100%Clinical Stage p = 0.0291580.0%213796.3%33883.8%MDAPI Score P = 0.506Low (0 or 1)12993.80%Int (2)3488.23%High (3)988.89%*MDAPI Score Factors  cN Stage P = 0.305cN0-N116593.3%cN2-N31070%LVI P = 0.453No-LVI15793.5%Yes-LVI2390.9%pT&gt;2cm P = 0.158Residual Tumor Morphology P = 0.055Multifocal Resid Tumor5996.5%Solitary Mass6690.6%No Resid Tumor5394.3%*These factors make up the MDA Prognostic Index

Conclusion: Overall the 5-year LRR-free survival was high at 93.18%, which compares favorably to similar neoadjuvant patient cohorts who receive mastectomy instead of BCS. Our analysis indicates clinical stage and pathologic stage are significant in predicting LRR. Of the four predictive factors utilized by the MDAPI, only multifocal residual disease showed weak predictive power (p = 0.055) in our population; however, it correlated with higher LRR-free survival, the opposite of its indication in the MDAPI. The MDAPI was not useful in our patient population; the risk groups did not significantly correlate with LRR-free survival. This may be secondary to low total number of recurrence events and also the small number of patients in the MDAPI-high group (9 patients had an MDAPI score of 3, and none had a score of 4). As further data emerge regarding biology of tumors and recurrence, it may be a combination of molecular profiling and residual cancer burden that is a better predictor for LRR.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-12.

Risk factors for anemia in children under 6 years of age in Ethiopia: analysis of the data from the cross-sectional Malaria IndicatorSurvey, 2007

BACKGROUND

Malaria is a leading cause of morbidity in Ethiopia. However, its transmission varies in both space and time, and large areas of the country are hypoendemic and epidemic-prone. The Ethiopia National Malaria Indicator Survey 2007 is a cross-sectional, nationally-representative household survey. The objective of the analyses presented here were to use the survey's data to identify factors associated with anemia presence in children under 6 years of age (U6); specifically, investigate the association between malaria and anemia; and discuss using anemia as a malaria proxy biomarker in the Ethiopian hypo-endemic transmission setting.

METHODS

The survey sampled 4185 households in 347 enumeration areas ≤2500 m above sea level. Primary outcome was increasing anemia severity in sampled children: no anemia (Hb: ≥11g/dl); mild anemia (Hb: ≥8g/dl and <11g/dl); and moderate-severe anemia (Hb: <8g/dl). Secondary outcomes were positive malaria rapid diagnostic test (RDT) or blood slide microscopy.

RESULTS

The analysis included 6054 (92.0%) children U6 in 3962 households. The proportion of children with no anemia, mild anemia, and moderate-severe anemia was 63.6%, 31.3%, and 5.1%, respectively. The overall prevalence of anemia (Hb <11g/dl) was 36.4% (95% CI 34.4-38.4). Factors independently associated with reduced relative odds of anemia categories were age (OR=0.7, 95% CI 0.7-0.7) and female sex (OR=0.9, 95% CI 0.8-1.0); malaria RDT positivity was associated with increased relative odds of a more severe anemia category (OR=5.8, 95% CI 3.7-9.2).

CONCLUSIONS

We conclude that at altitudes ≤2500 m malaria appears to be a significant risk factor for anemia; potentially anemia could be used as a useful proxy biomarker for malaria and its control in Ethiopia.

Gadoxetic acid-enhanced MRI for T-staging of gallbladder carcinoma: emphasis on liver invasion

OBJECTIVE

To evaluate the diagnostic performance of gadoxetic acid-enhanced MRI with an emphasis on the usefulness of the hepatobiliary phase (HBP) in T-staging of gallbladder carcinoma.

METHODS

66 patients with surgically confirmed gallbladder carcinoma underwent MRI. Two radiologists independently reviewed two sets of gadoxetic acid-enhanced MRI without and with the HBP. Local tumour spread was evaluated according to T-staging, and the results were compared with pathological findings. The diagnostic performance of two image sets to differentiate each T-stage was compared.

RESULTS

The sensitivities of MRI with the HBP to differentiate T1 vs ≥ T2 lesions, ≤ T2 vs ≥ T3 lesions and ≤ T3 vs T4 lesions were 96.3%, 85.7% and 100% for Observer 1 and 92.6%, 95.2% and 100% for Observer 2, respectively (p<0.0001). By adding the HBP, the sensitivities to differentiate ≤ T2 vs ≥ T3 lesions were increased from 66.7% to 85.7% for Observer 1 and from 81.0% to 95.2% for Observer 2, although there was no significant difference (p>0.05). The overall accuracies for T-staging were increased from 80.3% to 86.4% for Observer 1, a statistically significant degree (p=0.046), and from 83.8% to 87.9% for Observer 2 (p>0.05). The k-value for the two observers indicated excellent agreement.

CONCLUSION

Gadoxetic acid-enhanced MRI provided acceptable diagnostic performance for T-staging of gallbladder carcinoma. Addition of the HBP aids in the detection of liver invasion.

ADVANCES IN KNOWLEDGE

In the T-staging of gallbladder carcinoma, gadoxetic acid-enhanced MRI with the HBP may enhance detection of liver invasion.

A phase 1 trial of imatinib, bevacizumab, and metronomic cyclophosphamide in advanced colorectal cancer

Background:

This phase 1 clinical trial was conducted to determine the safety, maximum-tolerated dose (MTD), and pharmacokinetics of imatinib, bevacizumab, and metronomic cyclophosphamide in patients with advanced colorectal cancer (CRC).

Methods:

Patients with refractory stage IV CRC were treated with bevacizumab 5 mg kg⁻¹ i.v. every 2 weeks (fixed dose) plus oral cyclophosphamide q.d. and imatinib q.d. or b.i.d. in 28-day cycles with 3+3 dose escalation. Response was assessed every two cycles. Pharmacokinetics of imatinib and cyclophosphamide and circulating tumour, endothelial, and immune cell subsets were measured.

Results:

Thirty-five patients were enrolled. Maximum-tolerated doses were cyclophosphamide 50 mg q.d., imatinib 400 mg q.d., and bevacizumab 5 mg kg⁻¹ i.v. every 2 weeks. Dose-limiting toxicities (DLTs) included nausea/vomiting, neutropaenia, hyponatraemia, fistula, and haematuria. The DLT window required expansion to 42 days (1.5 cycles) to capture delayed toxicities. Imatinib exposure increased insignificantly after adding cyclophosphamide. Seven patients (20%) experienced stable disease for >6 months. Circulating tumour, endothelial, or immune cells were not associated with progression-free survival.

Conclusion:

The combination of metronomic cyclophosphamide, imatinib, and bevacizumab is safe and tolerable without significant drug interactions. A subset of patients experienced prolonged stable disease independent of dose level.

Temsirolimus combined with sorafenib in hepatocellular carcinoma: a phase I dose-finding trial with pharmacokinetic and biomarker correlates

BACKGROUND

Based upon preclinical evidence for improved antitumor activity in combination, this phase I study investigated the maximum-tolerated dose (MTD), safety, activity, pharmacokinetics (PK), and biomarkers of the mammalian target of rapamycin inhibitor, temsirolimus, combined with sorafenib in hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Patients with incurable HCC and Child Pugh score ≤B7 were treated with sorafenib plus temsirolimus by 3 + 3 design. The dose-limiting toxicity (DLT) interval was 28 days. The response was assessed every two cycles. PK of temsirolimus was measured in a cohort at MTD.

RESULTS

Twenty-five patients were enrolled. The MTD was temsirolimus 10 mg weekly plus sorafenib 200 mg twice daily. Among 18 patients at MTD, DLT included grade 3 hand-foot skin reaction (HFSR) and grade 3 thrombocytopenia. Grade 3 or 4 related adverse events at MTD included hypophosphatemia (33%), infection (22%), thrombocytopenia (17%), HFSR (11%), and fatigue (11%). With sorafenib, temsirolimus clearance was more rapid (P < 0.05). Two patients (8%) had a confirmed partial response (PR); 15 (60%) had stable disease (SD). Alpha-fetoprotein (AFP) declined ≥50% in 60% assessable patients.

CONCLUSION

The MTD of sorafenib plus temsirolimus in HCC was lower than in other tumor types. HCC-specific phase I studies are necessary. The observed efficacy warrants further study.

Establishing the Origin of Elevated Uranium Concentrations in Groundwater near the Central Ogcheon Metamorphic Belt, Korea

We examined the origin of the U-enriched groundwater in Daejeon, near the Ogcheon U zone in Korea. For this study, groundwater ionic species and C, S, and Sr isotopic compositions were analyzed. The U-enriched groundwater occurred only in the Daejeon granite region, while all the groundwater in the Ogcheon Supergroup showed very low U concentrations. In the granite region, the pedospheric or atmospheric origin of dissolved C and S means that the aquifer has been well connected to the oxidized surface environment. The Sr/Sr ratios indicated a lithospheric origin of Sr. Groundwater isotopic compositions in the Ogcheon belt varied greatly, indicating their complex sources. In this region, dissolved C originated from graphite-rich slate and limestone. The broad range of δS suggested that the composite sources included atmospheric SO for most groundwater, lithogenic SO for mine drainage and quarry water, and anthropogenic SO for polluted groundwater. This study indicates that the U-enriched groundwater is not related to the present U ores in the Ogcheon belt but is genetically associated with the granite body itself. The varying but considerable U contents within the granite body can be present as isolated groups. We infer that locally high U contents in the Daejeon granite might inherently be due to assimilation of the Ogcheon U-mineralized zone into granitic melt during the Mesozoic; however, the pH and Eh conditions except aquifer geology were very important factors in developing highly enriched U groundwater in the Daejeon granite region. Thermodynamic modeling highlights the importance of dissolved Ca and (bi-)carbonate in U geochemistry.

Successive magnetic phase transitions and multiferroicity in the spin-one triangular-lattice antiferromagnet Ba3NiNb2O9

We report the magnetic and electric properties of Ba3NiNb2O9, which is a quasi-two-dimensional spin-one triangular-lattice antiferromagnet with trigonal structure. At low T and with increasing magnetic field, the system evolves from a 120 degree magnetic ordering phase (A phase) to an up-up-down (uud) phase (B phase) with a change of slope at 1/3 of the saturation magnetization, and then to an "oblique" phase (C phase). Accordingly, the ferroelectricity switches on at each phase boundary with appearance of spontaneous polarization. Therefore, Ba3NiNb2O9 is a unique triangular-lattice antiferromagnet exhibiting both uud phase and multiferroicity.

Promoter methylation status of VEGF receptor genes: a possible epigenetic biomarker to anticipate the efficacy of intracellular-acting VEGF-targeted drugs in cancer cells

We evaluated whether the inhibitory effects of vascular endothelial growth factor (VEGF)-targeted drugs on the proliferation of cancer cells differed according to VEGF receptor (VEGFR) genes, Flt1 and KDR, promoter methylation status. Five hyper-VEGFR-methylation and six no-VEGFR-methylation cancer cells were used for the present study, together with human umbilical endothelial cells (HUVECs) as a control. No-VEGFR-methylation cancer cells showed higher expression of Flt1 and KDR than hyper-VEGFR-methylation cancer cells. Hyper-VEGFR-methylation cancer cells only showed increased expression and protein levels of Flt1 and KDR after treatment with the demethylase 5-aza-2'-deoxycytidine. Two drugs (a VEGF-specific-antibody, bevacizumab, and a KDR-specific-antibody) targeting extracellular VEGF-VEGFR signaling and two VEGF-specific-tyrosine kinase inhibitors (PTK/ZK and sunitinib) targeting intracellular VEGFR signaling were used in the cell proliferation assay. HUVECs showed dose- and time-dependent proliferation decrease with all tested drugs over a 72 h incubation period. No- or hyper-VEGFR-methylation cancer cells showed no significant proliferation differences after treatment with VEGF-specific-antibody or VEGFR2-specific-antibody. After PTK/ZK or sunitinib treatment, no-VEGFR-methylation cancer cells showed dose- or time-dependent decreases in proliferation. Hyper-VEGFR-methylation cancer cells also showed proliferation inhibition by VEGF-specific-tyrosine kinase inhibitors after demethylation of Flt1 and KDR. Proliferation inhibition synergistically increased after combination of demethylation with PTK/ZK in hyper-VEGF-methylation cancer cells. We observed that intracellular targeting of VEGF-VEGFR signaling could be more effective than extracellular targeting of the pathway in the suppression of proliferation of some cancer cells. In particular, the efficacy of intracellular targeting of VEGF-specific-tyrosine kinase inhibitors might be influenced by the epigenetic alteration of VEGFRs.

Optical self-energy in graphene due to correlations

In highly correlated systems one can define an optical self-energy in analogy to its quasiparticle (QP) self-energy counterpart. This quantity provides useful information on the nature of the excitations involved in inelastic scattering processes. Here we calculate the self-energy of the intraband optical transitions in graphene originating in the electron-electron interaction (EEI) as well as electron-phonon interaction (EPI). Although optics involves an average over all momenta (k) of the charge carriers, the structure in the optical self-energy is nevertheless found to mirror mainly that of the corresponding quasiparticles for k equal to or near the Fermi momentum k(F). Consequently, plasmaronic structures which are associated with momenta near the Dirac point at k = 0 are not important in the intraband optical response. While the structure of the electron-phonon interaction (EPI) reflects the sharp peaks of the phonon density of states, the excitation spectrum associated with the electron-electron interaction is in comparison structureless and flat and extends over an energy range which scales linearly with the value of the chemical potential. We introduce a method whereby detailed quantitative information on such excitation spectra can be extracted from optical data. Modulations seen on the edge of the interband optical conductivity as it rises towards its universal background value are traced to structure in the quasiparticle self-energies around k(F) of the lower Dirac cone associated with the occupied states.

Timing of audiovisual inputs to the prefrontal cortex and multisensory integration

A number of studies have demonstrated that the relative timing of audiovisual stimuli is especially important for multisensory integration of speech signals although the neuronal mechanisms underlying this complex behavior are unknown. Temporal coincidence and congruency are thought to underlie the successful merging of two intermodal stimuli into a coherent perceptual representation. It has been previously shown that single neurons in the non-human primate prefrontal cortex integrate face and vocalization information. However, these multisensory responses and the degree to which they depend on temporal coincidence have yet to be determined. In this study we analyzed the response latency of ventrolateral prefrontal (VLPFC) neurons to face, vocalization and combined face-vocalization stimuli and an offset (asynchronous) version of the face-vocalization stimulus. Our results indicate that for most prefrontal multisensory neurons, the response latency for the vocalization was the shortest, followed by the combined face-vocalization stimuli. The face stimulus had the longest onset response latency. When tested with a dynamic face-vocalization stimulus that had been temporally offset (asynchronous) one-third of multisensory cells in VLPFC demonstrated a change in response compared to the response to the natural, synchronous face-vocalization movie. Our results indicate that prefrontal neurons are sensitive to the temporal properties of audiovisual stimuli. A disruption in the temporal synchrony of an audiovisual signal which results in a change in the firing of communication related prefrontal neurons could underlie the loss in intelligibility which occurs with asynchronous speech stimuli.

Small (≤ 2 cm) hepatocellular carcinoma in patients with chronic liver disease: comparison of gadoxetic acid-enhanced 3.0 T MRI and multiphasic 64-multirow detector CT

OBJECTIVES

To compare the diagnostic performance of gadoxetic acid-enhanced MRI using 3.0 T with that of multiphasic 64-multirow detector CT (MDCT) for the detection of small (≤2 cm) hepatocellular carcinoma (HCC) in patients with chronic liver disease.

METHODS

A total of 54 patients (44 men, 10 women; age range, 33-81 years) with 59 HCCs (≤2 cm in diameter) who underwent both multiphasic (arterial, portal venous, equilibrium) 64-MDCT and gadoxetic acid-enhanced 3.0 T MRI were enrolled in this study. Two observers independently and randomly reviewed the MR and CT images on a lesion-by-lesion basis. The diagnostic performance of these techniques for the detection of HCC was assessed by alternative free-response receiver operating characteristic (ROC) analysis, in addition to evaluating the sensitivity and positive predictive value.

RESULTS

For each observer, the areas under the ROC curve were 0.874 and 0.863 for MRI, respectively, as opposed to 0.660 and 0.687 for CT, respectively. The differences between the two techniques were statistically significant for each observer (p<0.001). The sensitivities (89.8% and 86.4%) of MRI for both observers were significantly higher than those (57.6% and 61.0% for each observer, respectively) of MDCT. No significant difference was seen between the positive predictive values for the two techniques (p>0.05).

CONCLUSION

Gadoxetic acid-enhanced 3.0 T MRI shows a better diagnostic performance than that of 64-MDCT for the detection of small (≤2 cm) HCCs in patients with chronic liver disease.

Phase I clinical trial of the Src inhibitor dasatinib with dacarbazine in metastatic melanoma

Background:

Src inhibitors sensitise melanoma cells to chemotherapy in preclinical models. The combination of dasatinib and dacarbazine was tested in a phase I trial in melanoma.

Methods:

Patients had ECOG performance status 0–2 and normal organ function. Dacarbazine was administered on day 1 and dasatinib on day 2 through 19 of each 21-day cycle. Both were escalated from 50 mg b.i.d. of dasatinib and 800 mg m⁻² of dacarbazine. Available pre-treatment biopsies were sequenced for BRAF, NRAS, and C-Kit mutations.

Results:

Dose-limiting toxicity was reached at dasatinib 70 mg b.i.d./dacarbazine 1000 mg m⁻², and was predominantly haematological. In 29 patients receiving dasatinib 70 mg b.i.d., the objective response rate (ORR) was 13.8%, the clinical benefit rate (ORR+SD) was 72.4%, the 6-month progression-free survival (PFS) was 20.7%, and the 12-month overall survival (OS) was 34.5%. Two out of three patients who were wild type for BRAF, NRAS, and c-KIT mutations had confirmed partial responses, and one had a minor response.

Conclusion:

The recommended phase II dose is dasatinib70 mg b.i.d with dacarbazine 800 mg m⁻². PFS and OS data for dasatinib at 70 mg b.i.d. with dacarbazine compared favourably with historical controls. Preliminary data support evaluating tumour mutation status further as a biomarker of response.