7 research outputs found
The Present and Future Role of Insect-Resistant Genetically Modified Maize in IPM
Commercial, genetically-modified (GM) maize was first planted in the United States (USA, 1996) and Canada (1997) but now is grown in 13 countries on a total of over 35 million hectares (\u3e24% of area worldwide). The first GM maize plants produced a Cry protein derived from the soil bacteriumBacillus thuringiensis (Bt), which made them resistant to European corn borer and other lepidopteran maize pests. New GM maize hybrids not only have resistance to lepidopteran pests but some have resistance to coleopteran pests and tolerance to specific herbicides. Growers are attracted to the Btmaize hybrids for their convenience and because of yield protection, reduced need for chemical insecticides, and improved grain quality. Yet, most growers worldwide still rely on traditional integrated pest management (IPM) methods to control maize pests. They must weigh the appeal of buying insect protection “in the bag” against questions regarding economics, environmental safety, and insect resistance management (IRM). Traditional management of maize insects and the opportunities and challenges presented by GM maize are considered as they relate to current and future insect-resistant products. Four countries, two that currently have commercialize Bt maize (USA and Spain) and two that do not (China and Kenya), are highlighted. As with other insect management tactics (e.g., insecticide use or tillage), GM maize should not be considered inherently compatible or incompatible with IPM. Rather, the effect of GM insect-resistance on maize IPM likely depends on how the technology is developed and used
Ductal Carcinoma in situ: Underestimation of Percutaneous Biopsy and Positivity of Sentinel Lymph Node Biopsy in a Brazilian Public Hospital
Rafael da Silva Sá,1,2 Angela Flávia Logullo,3 Simone Elias,1 Gil Facina,1 Vanessa Monteiro Sanvido,1 Afonso Celso Pinto Nazário1 1Department of Gynaecology, Breast Surgery Team, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil; 2Universidade do Oeste Paulista (UNOESTE), Presidente Prudente, Brazil; 3Department of Pathology, Universidade Federal de São Paulo (UNIFESP), São Paulo, BrazilCorrespondence: Rafael da Silva SáDepartment of Gynaecology, Breast Surgery Team, Universidade Federal de São Paulo (UNIFESP), Rua Marselhesa, 249, São Paulo, SP, CEP 04020-060, BrazilTel +55 11 55764848Email [email protected]: Mammography screening has become widely spread and provided a marked increase in ductal carcinoma in situ (DCIS) diagnosis. In DCIS, the ductal epithelium proliferates without invasion through the basal cell membrane. However, histologic underestimation can happen in some cases.Objective: To analyze the rate of histologic underestimation (histopathologic results upgraded to invasive carcinoma after surgery) and the rate of positive results of sentinel lymph node biopsy (SLNB) in patients diagnosed with DCIS in a Brazilian public hospital.Methods: We reviewed medical records of all consecutive patients admitted between 2009 and 2013 whose initial diagnosis was DCIS through core needle biopsy. DCIS cases with a high risk of invasion underwent SLNB. We excluded cases with invasion or micro-invasion components in the first biopsy.Results: A total of 86 women were included, most with microcalcifications as the primary radiological lesion (73.2%), and underwent preoperative biopsy, with an invasive component in 21 (24.4%) in the final pathology report. Most had invasive carcinoma of no special type (NST): 52.3% (n = 11) and microinvasive tumors (7 cases, 33.3%). The main factors associated with histologic underestimation were nodular lesion (61.9%, p< 0.001) and an ultra-sonography-guided biopsy (71.4%, p=0.0005). The positivity rate of SLNB was 4.3%. All these patients underwent mastectomy, and the initial histologic pattern was solid DCIS.Conclusion: The “histologic underestimation” rate among patients with DCIS was not low, and less than 5% of patients who underwent SLNB had axillary positivity. This result suggests that patients who have DCIS and a high risk of invasion and undergoing mastectomy should have SLNB. As to the patients who will undergo lumpectomy, SLNB could be omitted and could be performed if patients have upgraded to invasive breast cancer.Keywords: breast cancer, ductal carcinoma in situ, underestimation rates, positive sentinel lymph nod
Invasive Species Control and Resolution of Wildlife Damage Conflicts: A Framework for Chemical and Genetically Based Management Methods
Vertebrate wildlife damage management relates to developing and employing methods to mitigate against damage caused by wildlife in the areas of food production, property damage, and animal or human health and safety. Of the many management tools available, chemical methods (e.g., toxicants) draw the most attention owing to issues related to environmental burden, species specificity, and humaneness. Research and development focusing on RNA interference and gene drives may be able to address the technical aspects of performance goals. However, there remain many questions about regulation, environmental risk, and societal acceptance for these emerging biological technologies. Here we focus on the development and use of these biological technologies for use in vertebrate pest management and conservation (e.g., management of wildlife diseases). We then discuss the regulatory framework and challenges these technologies present and conclude with a discussion on factors to consider for enabling these technologies for pest management and conservation applications under a commercially applied framework