Blends of HDPE wastes: study of the properties

In this work we have analysed the properties of blends of recycled high-density polyethylene (HDPE) filled with talc. We have used two kinds of polymer matrices. The first one came entirely from ground injection moulded parts whereas the second was bimodal, incorporating 80% of the previous HDPE and 20% of recycled HDPE coming from bottles. We have also used two kinds of commercial talc characterized by a medium particle size of 2 microm and 10 microm, respectively. The amount of talc added to both matrices weighed of 10% and 20%. With regards to the mechanical properties of the analysed composites, greater values of Young's modulus and break stresses were found using a smaller particle size and higher talc content. On the other hand, the combination of the two HDPEs with very different viscosities produced a notable increase in the strain at break and in the absorbed energy; both measured at high and low strain rates. Despite the differences in viscosities between the two HDPEs, we did not observe separation of phases during either the processing or testing. Under impact loading, the higher energy absorption in the composites was observed when the finest talc grade with a 10% content weight was added to the bimodal matrix.

Antitumoral and antimetastatic effects of metronomic chemotherapy with cyclophosphamide combined with celecoxib on murine mammary adenocarcinomas

PURPOSE

Metronomic chemotherapy (MCT) refers to the chronic and equally spaced administration of low doses of different chemotherapy drugs, without extended interruptions. Previously, we demonstrated the antitumor effect of MCT with cyclophosphamide (Cy) in a mouse mammary adenocarcinoma model. Herein, we investigated the therapeutic efficacy of metronomic Cy combined with celecoxib (Cel) in two murine mammary adenocarcinoma models.

METHODS

Mice were s.c. challenged with M-234 p or M-406 mammary tumors and from day 5 or 8 on, respectively, treated with: (I) no treatment (controls); (II) Cy in the drinking water (25-30 mg/kg body weight/day); (III) Cel (30 mg/kg p.o.), five times/week; (IV) treated as II + III. Mice challenged i.v. with M-234 p or M-406 tumor cells received, on day 3, the same treatments.

RESULTS

We found that MCT with Cy plus Cel inhibited tumor growth decreased lung metastases, and increased the median survival time, in both tumor models, having very low toxicity. MCT with Cy combined with Cel was more effective than each monotherapy.

CONCLUSIONS

The therapeutic benefits of combined MCT with cyclophosphamide plus celecoxib on mammary adenocarcinomas together with its very low toxicity profile warrant further study in an attempt to make the translation into the clinic.

Abstract 3655: Metronomic chemotherapy with cyclophosphamide (Cy) and celecoxib (Cel) in murine mammary adenocarcinoma tumor models: Mechanism of action

Metronomic chemotherapy (MCT) refers to the chronic, equally spaced, delivery of low doses of different chemotherapeutic drugs, without extended interruptions. CY, administered in low dose, is able to modulate the immune response. It can also reduce tumor angiogenesis, like the COX-2 inhibitor CEL does. We have already demonstrated that the administration, as an intervention strategy, of metronomic CY + CEL in M-406 and M-234p mammary adenocarcinomas-bearing mice inhibited tumor growth, increasing the survival rate. Our present aim was to study the mechanism by which that therapeutic effect was achieved. CBi and Balb/c inbred mice were s.c. challenged on day 0 with M-406 or M-234p mammary tumors, respectively, and treated from day 8 (M-406) and 5 (M-234p) on with: I) no further treatment (controls); II) CY in the drinking water (25-30 mg/kg body weight/day); III) CEL (30 mg/kg p.o.), five times/week; IV) Treated as II + III. Blood samples were taken on days 0, 20 (M-406) and 30 (M-324p) to evaluate VEGF serum level determined by ELISA and the % of circulating regulatory T cells (Tregs) by flow cytometry. The same tumor challenges and therapeutic schedules were performed in nude mice. Tumors were excised on days 20 and 30 for M-406 and M-234p, respectively, fixed and paraffin embedded for detection by immunohistochemistry of CD34 and Ki67 molecules. The VEGF serum level of M-406-bearing control animals (group I) was, on day 20, significantly higher than that measured on day 0 (p<0,001), while groups II, III y IV showed, on day 20, lower values than group I (p<0.01) in the same day, and similar than those on day 0. The % of CD4+ CD25+ Foxp3+ Treg cells in serum showed no differences between days 0 and 20 in all the experimental groups. The antitumoral effect of MCT was the same in euthymic and athymic mice. Immunohistochemistry for CD34 showed slight differences between control and treated animals that were not significant. Also, the staining for the proliferation marker Ki67 did not evinced differences among the experimental groups. The results obtained with M-234p tumor model were similar to those of M-406. In conclusion, the antitumor effect of MCT with CY plus CEL in mammary tumor models would be achieved, at least in part, by the inhibition of tumor angiogenesis, without modulation of the antitumor immune response.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3655.

Neuroblastoma in patients under 18 months. Single institution experience in Argentina

The purpose of the study was to evaluate the outcome of patients under 18 months diagnosed with neuroblastoma. Between April 2006 and December 2013, 45 consecutive patients followed in Hospital de Pediatría Garrahan, were retrospectively reviewed. With a median age of 9.3 months (1-18 months) N-myc amplification was detected in 5 out of 38 patients, 1p deletion (del1p) in 4 patients, and 11q aberration in one patient. With a median follow-up of 53 (range: 6-109 months), at 24 months the event free survival (EFS) of all patients was 83% (SE 6%) and overall survival (OS) of 88% (SE 5%). Significant difference was found in OS and EFS between patients with stages L1, L2 and Ms vs. stage M (p = 0.01 and p = 0.01 respectively). EFS for each stage: L1 85% (SE 7%), L2 100%, MS 100%, vs. M 55% (SE 16%). OS: L1 90% (SE 6%), L2 100%, MS 100%, vs. M 66% (SE 15%). OS and EFS results are similar to those reported in international studies. However, better identification of biological prognostic factors will warr ant accurate staging and consequently an appropriate treatment.

[Immunomodulation and antiangiogenesis in cancer therapy. From basic to clinical research]

Basic and pre-clinic research in cellular and molecular oncology are the main supports accounting for the advancement in cancer therapeutics. The findings achieved, and their implementation in clinical practice are responsible for the permanent improvement in the treatment of the neoplastic disease. Our present objective is to summarize and discuss the pre-clinical findings in immunomodulation and anti-angiogenesis for the treatment of several types of tumors obtained in our Institute during the last 15 years, and the subsequent translation and application of the acquired experimental knowledge in a Phase I/II Clinical Trial. We present the results and mechanisms of action of antimetastatic immunomodulation with cyclophosphamide, the metronomic chemotherapy with different single drugs and their combinations, and finally the design and preliminary results of a clinical trial with metronomic chemotherapy for patients with advanced breast cancer.

Malignant extra-cranial germ cell tumors in children and adolescents. Results following the guidelines of SFOP/SFCE 95 Protocol

Between September 1995 and December 2010, 99 new consecutive assessable patients with extra-cranial MGCT were treated according to SFOP/SFCE TGM95 Protocol. A "watch and wait" strategy for completely resected stage I-II was observed in cases with preoperative high tumor markers levels. Metastatic disease or alpha fetoprotein levels > 15 000 ng/ml cases were treated by VIP chemotherapy (etoposide, ifosfamide and CDDP) 4-6-courses. All other cases were treated by VBP (vinblastine, bleomycin, and CDDP) 3-5 courses. Median age for the whole group was 11.1 (r: 0-17) years. Males: 49, females: 50. Stage I: 19 patients, stage II: 16, stage III: 31 and stage IV: 3. Gonadal disease occurred in 77 cases. Of 21 completely resected stage I-II patients with MGCT who did not receive chemotherapy after surgery, 6 presented disease progression and were successfully treated by chemotherapy and remained disease-free. There were no significant differences in outcome according to age, gender, initial site, staging, and histological variant or high levels of alpha-fetoprotein. Initial non-responsiveness to VIP chemotherapy was the only significant unfavorable prognostic feature. With a median follow-up of 64 (r: 5-204) months, at 10 years EFS and OS estimates for the whole group were 0.82 (SE = 0.05) and 0.90 (SE = 0.03) respectively. Therapy results of MGCT treated with the SFOP/SFCE 95 strategy were excellent. Initial non-response to front line chemotherapy was the only significant adverse prognostic feature. The "watch and wait" strategy for completely resected disease with initial positive markers proved to be safe with optimal outcome.