289 research outputs found

    Effect of Threonine and the Bioactive Component of Saccharomyces Cerevisiae on the Productive Performance of the Broiler Cobb 500

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    This study was conducted in Chimborazo province, Riobamba Canton to evaluate the effect of threonine and the bioactive component of Saccharomyces cerevisiae on the productive performance of the broiler Cobb 500. A total of 270 one-day-old broiler chicken of both sexes were included, which corresponded to an experimental unit size of 15 birds. Two growth promoters were used for the treatments -- T1: Threonine (aminoacid) 200 g/Tn; and T2: bioactive oligosaccharides, obtained from the cell wall of selected strains of S. Cerevisiae (probiotic) 750 g/Tn. These were compared to a control group. The data were analyzed through Analysis of Variance (ADEVA). The separation of means was performed using the Tukey statistic at a level of significance of p < 0.05 and p < 0.01. The data were processed using the Infostat software version 2010. The results showed that the best productive yields were with treatment 2; the values for this treatment were: weight at 28 days: 1369.42 g; weight gain at 28 days: 48.90 g; food conversion at 28 days: 1.39 points; carcass weight: 2527.05 g; and yield to the carcass: 83.85%. Through the economic analysis, it was determined that the highest cost-benefit index was 1.30 USD with the application of T2. So according to the results, a better use of the nutrients that are present in the feed is achieved when bioactive components of S. cerevisiae are supplied in the diet of broiler chickens. Keywords: Threonine, Saccharomyces cerevisiae, productive performance, broiler, Cobb 500. RESUMEN Se realizó un experimento en la provincia de Chimborazo, Cantón Riobamba, para evaluar los efectos de treonina y componentes bioactivos de Saccharomyces cerevisiae sobre el comportamiento productivo en aves Cobb 500. Se utilizaron 270 pollitos mixtos Cobb 500 de un día de edad de ambos sexos, con un tamaño de unidad experimental de 15 aves. Para los tratamientos se manejaron dos promotores de crecimiento, T1: Treonina (aminoácido) 200 g/Tn y T2: Oligosacáridos bioactivos, obtenidos a partir de la pared celular de cepas seleccionadas de S. Cerevisiae750 g/Tn; frente a un testigo (T0). Los datos obtenidos fueron sometidos a Análisis de Varianza (ADEVA); la separación de medias se realizó mediante el estadístico Tukey a un nivel de significancia (p < 0,05) y (p < 0,01); los datos se procesaron mediante el software Infostat versión 2010. Los resultados muestran los mejores rendimientos productivos con el Tratamiento 2, para los parámetros: peso a los 28 días 1369,42 g; ganancia de peso a los 28 días 48,90 g; y conversión alimenticia a los 28 días con 1,39 puntos; así como peso a la canal 2527,05 g; y rendimiento a la canal 83,85%. Mediante el análisis económico se determinó que el mayor índice beneficio costo fue de 1,30 USD con la aplicación del T2. Lo que brinda un indicativo que mediante el suministro de componentes bioactivos de S. cerevisiae en la dieta de pollos broiler, se logra un mejor aprovechamiento de los nutrientes que se encuentran presentes en el alimento, lo que se refleja en los parámetros productivos. Palabras clave: treonina, Saccharomyces cerevisiae, comportamiento productivo, broilers, Cobb 500

    Layered Structures of Ti-6Al-4V Alloy and Metal Matrix Composites on Its Base Joint by Diffusion Bonding and Friction Welding

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    Metallic layered structures demonstrate an advanced set of characteristics that combine different properties not found within homogenous bulk materials. Powder metallurgy (PM) is proven to be the most efficient way of fabrication of layered structures, including highly rated structures of Ti alloys. Residual porosity, however, remains one of the biggest problems of titanium-based PM products and this can adversely affect the mechanical properties and performance of the structural parts. Post-sintering hot deformation is a common way to control the porosity of metallic materials. Traditional thermomechanical processing like hot rolling, however, could not be applied on multi-layered structures due to the disparity of the different layers’ plastic flow. Separate processing of high performance individual layers to reach their best parameters, followed by post processing bonding of the mating subcomponents is a credible pathway for fabrication of the layered materials with highly optimized properties of each individual layer. In this study we used diffusion bonding (DB) and friction welding to join the parts made of Ti-6Al-4V alloy and metal matrix composites on the base of this alloy reinforced with 10% of either TiB or TiC. Parts were fabricated using blended elemental PM. Different protocols were used to join the materials: DB welding via rotational friction (RFW) and linear friction (LFW) as well as different geometries of mating subcomponents were tested. Structure characterization of the joints using light optical microscopy, SEM, EDS, EBSD as well as mechanical tests were performed. All used protocols were generally successful in bonding the parts made of Ti-64 alloy and composites on its base. The potential of DB, RFW and LFW of Ti-6Al-4V alloy and its MMC are discussed

    A systematic review of recent phase-II trials in refractory or recurrent osteosarcoma: Can we inform future trial design?

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    Background/Objective: To analyze changes in recurrent/refractory osteosarcoma phase II trials over time to inform future trials in this population with poor prognosis.// Methods: A systematic review of trials registered on trial registries between 01/01/2017–14/02/2022. Comparison of 98 trials identified between 2003 and 2016. Publication search/analysis for both periods, last update on 01/12/2022.// Results: Between 2017 and 2022, 71 phase-II trials met our selection criteria (19 osteosarcoma-specific trials, 14 solid tumor trials with and 38 trials without an osteosarcoma-specific stratum). The trial number increased over time: 13.9 versus 7 trials/year (p = 0.06). Monotherapy remained the predominant treatment (62% vs. 62%, p = 1). Targeted therapies were increasingly evaluated (66% vs. 41%, P = 0.001). Heterogeneity persisted in the trial characteristics. The inclusion criteria were measurable disease (75%), evaluable disease (14%), and surgical remission (11%). 82% of the trials included pediatric or adolescent patients. Biomarker-driven trials accounted for 25% of the total trials. The survival endpoint use (rather than response) slightly increased (40% versus 31%), but the study H1/H0 hypotheses remained heterogeneous. Single-arm designs predominated over multiarm trials (n = 7). Available efficacy data on 1361 osteosarcoma patients in 58 trials remained disappointing, even though 21% of these trials were considered positive, predominantly those evaluating multi-targeted kinase inhibitors.// Conclusion: Despite observed changes in trial design and an increased number of trials investigating new therapies, high heterogeneity remained with respect to patient selection, study design, primary endpoints, and statistical hypotheses in recently registered phase II trials for osteosarcoma. Continued optimization of trial design informed by a deeper biological understanding should strengthen the development of new therapies

    R1507, an Anti-Insulin-Like Growth Factor-1 Receptor (IGF-1R) Antibody, and EWS/FLI-1 siRNA in Ewing's Sarcoma: Convergence at the IGF/IGFR/Akt Axis

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    A subset of patients with Ewing's sarcoma responds to anti-insulin-like growth factor-1 receptor (IGF-1R) antibodies. Mechanisms of sensitivity and resistance are unknown. We investigated whether an anti-IGF-1R antibody acts via a pathway that could also be suppressed by small interfering (si) RNA against the EWS/FLI-1 fusion protein, the hallmark of Ewing's sarcoma. The growth of two Ewing's sarcoma cell lines (TC-32 and TC-71) was inhibited by the fully human anti-IGF-1R antibody, R1507 (clonogenic and MTT assays). TC-32 and TC-71 cells express high levels of IGF-2, while RD-ES and A4573 Ewing's cell lines, which were less responsive to R1507 in our assays, express low or undetectable IGF-2, respectively. TC-71 cells also expressed high levels of IGF-1R, and R1507 decreased steady-state levels of this receptor by internalization/degradation, an effect which was associated with a decrease in p-IGF-1R, p-IRS-1, and p-Akt. EWS/FLI-1 siRNA also decreased p-Akt, due to its ability to increase IGF-BP3 levels and subsequently decrease IGF-1 and IGF-2 levels, thus inhibiting signaling through p-IGF-1R. This inhibition correlated with growth suppression and apoptosis. The attenuation of Akt activation was confirmed in TC-71 and HEK-293 (human embryonic kidney) cells by transfecting them with IGF-1R siRNA. We conclude that antibodies and siRNA to IGF-1R, as well as siRNA to EWS/FLI-1, act via intersecting IGF/IGF-1R signals that suppress a common point in this pathway, namely the phosphorylation of Akt

    Prognostic factors in localized Ewing's tumours and peripheral neuroectodermal tumours: the third study of the French Society of Paediatric Oncology (EW88 study)

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    Purpose: (1) To improve survival rates in patients with Ewing's sarcoma (ES) or peripheral neuroectodermal tumours (PNET) using semi-continuous chemotherapy and aiming to peform surgery in all; (2) To identify early prognostic factors to tailor therapy for future studies. Patients and methods One hundred and forty-one patients were entered onto the trial between January 1988 and December 1991. Induction therapy consisted of five courses of Cytoxan, 150 mg/m2 × 7 days, followed by Doxorubicin, 35 mg/m2 i.v on day 8 given at short intervals. Surgery was recommended whenever possible. The delivery of radiation therapy was based on the quality of resection and the histological response to CT. Maintenance chemotherapy consisted of vincristine + actinomycin and cytoxan + doxorubicin. The total duration of therapy was 10 months. Results After a median follow-up of 8.5 years, the projected overall survival at 5 years was 66% and disease-free survival (DFS) was 58%. In patients treated by surgery, only the histological response to CT had an influence on survival: 75% DFS for patients with a good histological response (less than 5% of cells), 48% for intermediate responders and only 20% for poor responders (≥ 30% of cells), P < 0.0001. The initial tumor volume by itself had no influence on DFS in these patients. In contrast, the tumour volume had a strong impact on DFS in patients treated by radiation therapy alone. Age had no impact on outcome. Conclusion Therapeutic trials for localized Ewing's sarcoma should be based on the histological response to chemotherapy or on the tumour volume according to the modality used for local therapy. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Acute myeloid leukemia of donor origin after allogeneic stem cell transplantation from a sibling who harbors germline XPD and XRCC3 homozygous polymorphisms

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    A 54-year-old woman was diagnosed with infiltrative ductal breast carcinoma. Two years after treatment, the patient developed an acute myeloid leukemia (AML) which harbored del(11q23) in 8% of the blast cells. The patient was submitted for allogeneic stem cell transplantation (aSCT) from her HLA-compatible sister. Ten months after transplantation, she relapsed with an AML with basophilic maturation characterized by CD45low CD33high, CD117+, CD13-/+, HLA Drhigh, CD123high, and CD203c+ blast cells lacking expression of CD7, CD10, CD34, CD15, CD14, CD56, CD36, CD64, and cytoplasmic tryptase. Karyotype analysis showed the emergence of a new clone with t(2;14) and FISH analysis indicated the presence of MLL gene rearrangement consistent with del(11q23). Interestingly, AML blast cell DNA tested with microsatellite markers showed the same pattern as the donor's, suggesting that this AML emerged from donor cells. Additionally, polymorphisms of the XPA, XPD, XRCC1, XRCC3 and RAD51 DNA repair genes revealed three unfavorable alleles with low DNA repair capacity

    Clinical characteristics and prognosis of osteosarcoma in young children: a retrospective series of 15 cases

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    <p>Abstract</p> <p>Background</p> <p>Osteosarcoma is the most common primary bone malignancy in childhood and adolescence. However, it is very rare in children under 5 years of age. Although studies in young children are limited in number, they all underline the high rate of amputation in this population, with conflicting results being recently reported regarding their prognosis.</p> <p>Methods</p> <p>To enhance knowledge on the clinical characteristics and prognosis of osteosarcoma in young children, we reviewed the medical records and histology of all children diagnosed with osteosarcoma before the age of five years and treated in SFCE (Société Française des Cancers et leucémies de l'Enfant) centers between 1980 and 2007.</p> <p>Results</p> <p>Fifteen patients from 7 centers were studied. Long bones were involved in 14 cases. Metastases were present at diagnosis in 40% of cases. The histologic type was osteoblastic in 74% of cases. Two patients had a relevant history. One child developed a second malignancy 13 years after osteosarcoma diagnosis.</p> <p>Thirteen children received preoperative chemotherapy including high-dose methotrexate, but only 36% had a good histologic response. Chemotherapy was well tolerated, apart from a case of severe late convulsive encephalopathy in a one-year-old infant. Limb salvage surgery was performed in six cases, with frequent mechanical and infectious complications and variable functional outcomes.</p> <p>Complete remission was obtained in 12 children, six of whom relapsed. With a median follow-up of 5 years, six patients were alive in remission, seven died of their disease (45%), in a broad range of 2 months to 8 years after diagnosis, two were lost to follow-up.</p> <p>Conclusions</p> <p>Osteosarcoma seems to be more aggressive in children under five years of age, and surgical management remains a challange.</p

    Pediatric T- and NK-cell lymphomas: new biologic insights and treatment strategies

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    T- and natural killer (NK)-cell lymphomas are challenging childhood neoplasms. These cancers have varying presentations, vast molecular heterogeneity, and several are quite unusual in the West, creating diagnostic challenges. Over 20 distinct T- and NK-cell neoplasms are recognized by the 2008 World Health Organization classification, demonstrating the diversity and potential complexity of these cases. In pediatric populations, selection of optimal therapy poses an additional quandary, as most of these malignancies have not been studied in large randomized clinical trials. Despite their rarity, exciting molecular discoveries are yielding insights into these clinicopathologic entities, improving the accuracy of our diagnoses of these cancers, and expanding our ability to effectively treat them, including the use of new targeted therapies. Here, we summarize this fascinating group of lymphomas, with particular attention to the three most common subtypes: T-lymphoblastic lymphoma, anaplastic large cell lymphoma, and peripheral T-cell lymphoma-not otherwise specified. We highlight recent findings regarding their molecular etiologies, new biologic markers, and cutting-edge therapeutic strategies applied to this intriguing class of neoplasms

    Does chemotherapy-induced neutropaenia result in a postponement of adjuvant or neoadjuvant regimens in breast cancer patients? Results of a retrospective analysis

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    In 2005, 224 patients received adjuvant/neoadjuvant chemotherapy for breast cancer in a single institution according to daily practices. Regimens consisted of epirubicin-based chemotherapy (FEC100, four or six cycles), or three cycles of FEC100 followed by three cycles of docetaxel. An absolute blood count was carried out every 3 weeks, 1–3 days before planned chemotherapy cycle. Overall, 1238 cycles were delivered. An absolute neutrophil count (ANC) <1.5 × 109 l−1 before planned chemotherapy was found in 171 cycles. Of these, 130 cycles (76%) were delivered as planned regardless of whether ANC levels recovered, and 41 (24%) were delayed. None of these patients developed a febrile neutropaenia. Haematopoietic support (granulocyte colony-stimulating factor (G-CSF)) was required in 12 cycles. We found that the majority of patients with an ANC <1.5 × 109 l−1 before planned chemotherapy received planned doses, without complications and need for G-CSF
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