202 research outputs found

    FUSARIUM VERTICILLIOIDES IN MAIZE: HOW ABIOTIC AND BIOTIC FACTORS CAN INFLUENCE GROWTH AND FUMONISINS PRODUCTION IN FIELD AND DURING STORAGE

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    In questa tesi di dottorato sono stati indagati i punti critici legati ai fattori biotici e abiotici che possono influenzare la crescita del fungo Fusarium verticillioides, produttore di fumonisine in mais. le fumonisine sono metaboliti secondari prodotte da funghi appartenenti al genere Fusarium e sono state classificate come possibili cancerogene per l’uomo e per gli animali. Gli argomenti trattati nei vari capitoli sono stati: parametri ecologici che condizionano la crescita e l’accumulo di fumonisine nelle prime fasi post raccolta e durante lo stoccaggio; relazione che intercorre tra aw, umidita’ relativa e tipo di ibrido; controllo con mezzi chimici e biologici in campo e in vitro su F. verticillioides e A. flavus.The aim of this work was to collect missing information about critical point related to abiotic and biotic factors that can influence the growth of Fusarium verticillioides in maize and the consequent production of fumonisins in kernels. Fumonisins are secondary metabolites reported as toxigenic in humans and animals. Issues treated are: variables influencing growth and toxin accumulation during post-harvest and storage; the relationship between aw, relative humidity and type of hybrids; chemical and biological control of F. verticillioides e A. flavus in field and in vitro

    Myeloid-Derived Cells in Tumors: Effects of Radiation

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    The discrepancy between the in vitro and in vivo response to radiation is readily explained by the fact that tumors do not exist independently of the host organism; cancer cells grow in the context of a complex microenvironment composed of stromal cells, vasculature, and elements of the immune system. As the antitumor effect of radiotherapy depends in part on the immune system, and myeloid-derived cells in the tumor microenvironment modulate the immune response to tumors, it follows that understanding the effect of radiation on myeloid cells in the tumor is likely to be essential for comprehending the antitumor effects of radiotherapy. In this review, we describe the phenotype and function of these myeloid-derived cells, and stress the complexity of studying this important cell compartment owing to its intrinsic plasticity. With regard to the response to radiation of myeloid cells in the tumor, evidence has emerged demonstrating that it is both model and dose dependent. Deciphering the effects of myeloid-derived cells in tumors, particularly in irradiated tumors, is key for attempting to pharmacologically modulate their actions in the clinic as part of cancer therapy

    The convergence of radiation and immunogenic cell death signaling pathways.

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    Ionizing radiation (IR) triggers programmed cell death in tumor cells through a variety of highly regulated processes. Radiation-induced tumor cell death has been studied extensively in vitro and is widely attributed to multiple distinct mechanisms, including apoptosis, necrosis, mitotic catastrophe (MC), autophagy, and senescence, which may occur concurrently. When considering tumor cell death in the context of an organism, an emerging body of evidence suggests there is a reciprocal relationship in which radiation stimulates the immune system, which in turn contributes to tumor cell kill. As a result, traditional measurements of radiation-induced tumor cell death, in vitro, fail to represent the extent of clinically observed responses, including reductions in loco-regional failure rates and improvements in metastases free and overall survival. Hence, understanding the immunological responses to the type of radiation-induced cell death is critical. In this review, the mechanisms of radiation-induced tumor cell death are described, with particular focus on immunogenic cell death (ICD). Strategies combining radiotherapy with specific chemotherapies or immunotherapies capable of inducing a repertoire of cancer specific immunogens might potentiate tumor control not only by enhancing cell kill but also through the induction of a successful anti-tumor vaccination that improves patient survival

    Global Breast Cancer: The Lessons to Bring Home

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    Breast cancer is the most common cancer affecting women globally. This paper discusses the current progress in breast cancer in Western countries and focuses on important differences of this disease in low- and middle-income countries (LMCs). It introduces several arguments for applying caution before globalizing some of the US-adopted practices in the screening and management of the disease. Finally, it suggests that studies of breast cancer in LMCs might offer important insights for a more effective management of the problem both in developing as well as developed countries

    The Role of a Prone Setup in Breast Radiation Therapy

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    Most patients undergoing breast conservation therapy receive radiotherapy in the supine position. Historically, prone breast irradiation has been advocated for women with large pendulous breasts in order to decrease acute and late toxicities. With the advent of CT planning, the prone technique has become both feasible and reproducible. It was shown to be advantageous not only for women with larger breasts but in most patients since it consistently reduces, if not eliminates, the inclusion of heart and lung within the field. The prone setup has been accepted as the best localizing position for both MRI and stereotactic biopsy, but its adoption has been delayed in radiotherapy. New technological advances including image-modulated radiation therapy and image-guided radiation therapy have made possible the exploration of accelerated fractionation schemes with a concomitant boost to the tumor bed in the prone position, along with better imaging and verification of reproducibility of patient setup. This review describes some of the available techniques for prone breast radiotherapy and the available experience in their application. The NYU prone breast radiotherapy approach is discussed, including a summary of the results from several prospective trials

    The evocative object. Innovation, reflexivity and transformation in university teaching

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    The paper offers an epistemological and pedagogical basis for using objects in teaching at university, inspired by the experience-based research and practice of object-based learning, here reframed by complexity theory and enactive, symbolic, and reflexive pedagogy. The paper proposes a teaching method where different languages and forms of knowledge are composed in order to favor the transformation of the students’ perspectives of meaning. The paper itself is written in such a way to connect different forms of knowledge: narration of experience sustains theorization, looking for embodied and subjectivated thinking. Theoretical concepts are developed through the analysis of an object-based didactic experience and the students’ reflexive reinterpretation of their own learning. The outcome of this study is the articulation of a practical theory of transformation, as an antidote to the dominant reductionist and functionalist understanding of innovation in HE didactics

    Penicillium populations in dry-cured ham manufacturing plants.

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    Seven ham manufacturing plants were sampled for 1 year to assess the mycoflora present in the air and on hams, with special attention given to potential mycotoxin producers. Temperature and relative humidity were recorded in the ripening rooms. Maturing rooms held hams from 2 to 3 through 6 to 7 ripening months, and aging rooms held hams for the following 6 to 7 months, until the 14-month ripening point, when they were ready for the market. Mean temperatures and relative humidities registered during the study were 14.9 degrees C and 62.4%, respectively, in maturing rooms and 16.3 degrees C and 57.6% in aging rooms. Aspergilli and penicillia, potential mycotoxin producers, were isolated in all the plants from the air and the ham. Aspergilli represented 5% of the isolates, while penicillia were largely dominant, with Penicillium nalgiovense being the most represented species (around 60% of the penicillia), followed by Penicillium nordicum, with 10 and 26% of the penicillia isolated, respectively, from the air or the ham. Ochratoxin A production ability, checked in vitro at 250C, was observed in 50% of the P. nordicum isolates obtained both from the air and the ham. Air and ham surface contamination by penicillia was greater in the ripening rooms, where higher temperatures were registered. A certain correlation was also observed between air and ham surface contamination. On the basis of this study, P. nordicum, the ochratoxin A producer that is notable on proteinaceous substrates, is normally present in ham manufacturing plants in Italy, even though not a dominant species. Further studies are necessary to clarify and ensure if dry-curing conditions minimize the potential risk of ochratoxin A formation in the product

    Comparison of Acute and Late Toxicity of Two Regimens of 3- and 5-Week Concomitant Boost Prone IMRT to Standard 6-Week Breast Radiotherapy

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    Purpose: Limited information is available comparing toxicity of accelerated radiotherapy (RT) to that of standard fractionation RT for early stage breast cancer. We report early and late toxicities of two prone regimens of accelerated intensity-modulated radiation therapy (IMRT) with a concomitant boost (CB) to the tumor bed delivered over 3 or 5 weeks as compared to standard 6 week RT with a sequential electron boost. Methods: From 2/2003 to 12/2007, 169 consecutive patients with Stage I–II breast cancer were offered the choice to undergo prone RT with either: a 6-week standard RT regimen of 46 Gy/23 fractions (fx) to the whole breast (WB), followed by a14 Gy sequential boost (SB) to the tumor bed (6wSB), a 5-week regimen of 50 Gy to WB with an IMRT CB of 6.25 Gy in 25 fx (5wCB); or a 3-week protocol of 40.5 Gy to WB with an IMRT CB of 7.5 Gy in 15 fx (3wCB). These regimens were estimated as biologically equivalent, based on alpha/beta = 4 for tumor control. Toxicities were reported using RTOG and LENT/SOMA scoring. Results: 51/169 patients chose standard 6wSB, 28 selected 5wCB, and 90 enrolled in 3wCB protocol. Maximum acute toxicity was Grade 3 dermatitis in 4% of the patients in the 6wSB compared 1% in 3wCB. In general, acute complications (breast pain, fatigue, and dermatitis) were significantly less in the 3wCB than in the other schedules (P < 0.05). With a median follow-up of 61 months, the only Grade 3 late toxicity was telangiectasia in two patients: one in 3wCB and one in 5wCB group. Notably, fibrosis was comparable among the three groups (P = NS). Conclusion: These preliminary data suggest that accelerated regimens of breast RT over 3 or 5 weeks in the prone position, with an IMRT tumor bed CB, result in comparable late toxicity to standard fractionation with a sequential tumor boost delivered over 6 weeks. As predicted by radiobiological modeling the shorter regimen was associated with less acute effects
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