Multiple delivery cesium oven system for negative ion sources

Distribution of cesium in large negative ion beam sources to be operational in ITER, is presently based on the use of three or more cesium ovens, which operate simultaneously and are controlled remotely. However, use of multiple Cs ovens simultaneously is likely to pose difficulties in operation and maintenance of the ovens. An alternate method of Cs delivery, based on a single oven distribution system is proposed as one which could reduce the need of simultaneous operation of many ovens. A proof of principle experiment verifying the concept of a multinozzle distributor based Cs oven has been carried out at Institute for Plasma Research. It is also observed that the Cs flux is not controlled by Cs reservoir temperature after few hours of operation but by the temperature of the distributor which starts behaving as a Cs reservoir.

Targeting both Notch and ErbB-2 signalling pathways is required for prevention of ErbB-2-positive breast tumour recurrence

BACKGROUND

We reported that Notch-1, a potent breast oncogene, is activated in response to trastuzumab and contributes to trastuzumab resistance in vitro. We sought to determine the preclinical benefit of combining a Notch inhibitor (γ-secretase inhibitor (GSI)) and trastuzumab in both trastuzumab-sensitive and trastuzumab-resistant, ErbB-2-positive, BT474 breast tumours in vivo. We also studied if the combination therapy of lapatinib plus GSI can induce tumour regression of ErbB-2-positive breast cancer.

METHODS

We generated orthotopic breast tumour xenografts from trastuzumab- or lapatinib-sensitive and trastuzumab-resistant BT474 cells. We investigated the antitumour activities of two distinct GSIs, LY 411 575 and MRK-003, in vivo.

RESULTS

Our findings showed that combining trastuzumab plus a GSI completely prevented (MRK-003 GSI) or significantly reduced (LY 411 575 GSI) breast tumour recurrence post-trastuzumab treatment in sensitive tumours. Moreover, combining lapatinib plus MRK-003 GSI showed significant reduction of tumour growth. Furthermore, a GSI partially reversed trastuzumab resistance in resistant tumours.

CONCLUSION

Our data suggest that a combined inhibition of Notch and ErbB-2 signalling pathways could decrease recurrence rates for ErbB-2-positive breast tumours and may be beneficial in the treatment of recurrent trastuzumab-resistant disease.

A phase II trial of motexafin gadolinium (MGd) in advanced non-small cell lung cancer (NSCLC) patients who had failed platinum-based chemotherapy: Preliminary results of stage 1

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Background: Motexafin gadolinium (MGd) is a tumor-selective antineoplastic agent that disrupts redox dependent pathways by targeting oxidative stress-related proteins such as thioredoxin reductase (TRX). TRX often is overexpressed in NSCLC and is associated with a poor prognosis. Inhibition of TRX reverses tumor phenotype in lung carcinoma cells in vitro and in vivo. This randomized 2-stage phase II trial investigated tumor response and survival with 2 regimens of single agent MGd for the 2nd line treatment of advanced NSCLC. Methods: Patients with locally advanced or metastatic NSCLC ± brain metastases, ECOG PS 0–1, who had received one prior platinum-based chemotherapy regimen ± kinase inhibitor were randomized to intravenous MGd (10 mg/kg/week - Group A) or MGd (15 mg/kg/q 3 weeks - Group B) given in 21 day cycles. The sample size was 30 per arm in stage 1, and 24 per arm in stage 2. Response was evaluated by RECIST every 6 weeks. Results: 51 evaluable patients, median age of 62 years (range 41–85), with locally advanced (14%) or metastatic (86%) adenocarcinoma (47%), squamous cell carcinoma (14%), large cell carcinoma (10%), bronchoalveolar carcinoma (2%) or other NSCLC (27%) were randomized to group A (N=22) or group B (N=29). 37% had not responded to first line chemotherapy. MGd treatment was well tolerated, with 1–12 cycles (median 2, mean 3) administered. The most common grade 3+ adverse events were hypophosphatemia (15.7%), fatigue (13.7%), dyspnea (9.8%), hypoxia (7.8%), and finger blisters (5.9%). 48 patients were evaluable for response, with a confirmed response rate of 4.2% (2 PR). Median time to progression was 7 weeks in each group, with 26% and 15% free from progression at 4 and 6 months, respectively. Median survival of 51 evaluable patients was 10.2 months (95% CI: 6.7 months - not reached), 9.2 months for group A and not reached at > 1 year for group B. Conclusions: MGd appears active as a single agent for second line treatment of NSCLC patients with advanced or metastatic NSCLC who have failed prior platinum-based chemotherapy, with a modest response rate and promising survival. The trial has met the criteria for continuation into stage 2 for each treatment group.

No significant financial relationships to disclose.

Effect of oral administration of bismuth compounds on Campylobacter colonization in broilers

Bismuth compounds have been used since the 18th century to treat gastrointestinal ailments in man. Colloidal bismuth subcitrate (De-Nol) is currently used in combination with antibiotics to reduce enteric Helicobacter pylori colonization as a treatment of stomach ulcers. We investigated whether bismuth citrate or its parent compound, colloidal bismuth subcitrate, would reduce colonization of the closely related foodborne pathogen, Campylobacter jejuni in chickens. In 2 studies, birds were either fed 0, 50, or 200 ppm bismuth citrate or bismuth subcitrate (De-Nol) for 10 or 21 d and were orally challenged with 7 combined strains of C. jejuni (n = 6 birds/treatment). For both treatment groups, cecal Campylobacter colonization was reduced when birds were fed 200 ppm for 10 d but not 21 d. For the 50 ppm treatment group, only birds dosed with bismuth citrate for 21 d demonstrated any reduction in cecal Campylobacter concentrations when compared with controls. These data suggest that bismuth citrate and colloidal bismuth subcitrate may reduce cecal colonization by Campylobacter in broilers, but these effects are inconsistent.