29 research outputs found

    Functional Analysis of the Asian Soybean Rust Resistance Pathway Mediated by Rpp2

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    Asian soybean rust is an aggressive foliar disease caused by the obligate biotrophic fungus Phakopsora pachyrhizi. On susceptible plants, the pathogen penetrates and colonizes leaf tissue, resulting in the formation of necrotic lesions and the development of numerous uredinia. The soybean Rpp2 gene confers resistance to specific isolates of P. pachyrhizi. Rpp2-mediated resistance limits the growth of the pathogen and is characterized by the formation of reddish-brown lesions and few uredinia. Using virus-induced gene silencing, we screened 140 candidate genes to identify those that play a role in Rpp2 resistance toward P. pachyrhizi. Candidate genes included putative orthologs to known defense-signaling genes, transcription factors, and genes previously found to be upregulated during the Rpp2 resistance response. We identified 11 genes that compromised Rpp2-mediated resistance when silenced, including GmEDS1, GmNPR1, GmPAD4, GmPAL1, five predicted transcription factors, an O-methyl transferase, and a cytochrome P450 monooxygenase. Together, our results provide new insight into the signaling and biochemical pathways required for resistance against P. pachyrhizi

    Small Cell Lung Cancer Presenting with Personality Change

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    Introduction: Paraneoplastic limbic encephalitis is a syndrome characterized by autoimmune inflammation of the limbic system in the setting of underlying malignancy. The syndrome presents with acute to subacute neuropsychiatric clinical findings, often before the cancer diagnosis is known. Clinical Findings: A 57-year-old woman with a 30 pack-year smoking history presented to Maine Medical Center after multiple generalized tonic-clonic seizures. Her family reported periodic odd behavior including confusion, disinhibition, and paranoia--all of which preceded her first seizure by two weeks. Diagnoses, interventions, and outcomes: MRI brain showed T2/FLAIR signal hyperintensity of the right amygdala and hippocampus with sparing of the right insular cortex and cingulate gyrus. Electroencephalogram showed frequent right temporal simple partial seizures. Cerebrospinal fluid was notable for mild pleocytosis and positive GABA-B-R antibodies with a titer of 1:32 (reference range Conclusions: This case illustrates the importance of early diagnosis and treatment of the syndrome of paraneoplastic limbic encephalitis. The strong association with often undiagnosed malignancy underscores this importance; as well as the opportunity for early initiation of tumor treatment

    Safety of long-term anticoagulation in patients with brain metastases.

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    Anticoagulation is thought to be associated with the risk of intracranial hemorrhage (ICH) in patients with brain metastases; however, the data on this topic are limited. This study was conducted to determine the incidence of ICH associated with anticoagulant use in adult patients with brain metastases. Consecutive patients with brain metastases occurring from 2006 to 2014 were identified from a single-institution database. Long-term anticoagulant therapy was defined as outpatient anticoagulation therapy of \u3e 1 month. Chi-square tests and Fisher\u27s exact test were used to compare rates of ICH by groups. This cohort included 125 patients with brain metastases. Of these, 64 had primary of non-small cell lung cancer (51.2%). Of these patients, 12/125 (9.6%) patients developed ICH. Neither the primary tumor site nor the number of brain metastases was associated with the development of ICH. ICH incidence was not associated with the use of anticoagulant therapy, with 8/67 (11.94%) patients on outpatient anticoagulation and 4/58 (6.9%) not on anticoagulation experiencing ICH (p = 0.33). The type of treatment did not significantly influence ICH, although those having combined WBRT and SRS were numerically more likely to experience ICH (4/15; 26.67%) of this cohort. In patients on enoxaparin, there was no difference in the incidence of ICH for daily versus twice-daily dosing (p = 1.0). Long-term anticoagulant use is not associated with an increased incidence of ICH in patients with intracranial metastases

    Functional Analysis of the Asian Soybean Rust Resistance Pathway Mediated by Rpp2

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    Asian soybean rust is an aggressive foliar disease caused by the obligate biotrophic fungus Phakopsora pachyrhizi. On susceptible plants, the pathogen penetrates and colonizes leaf tissue, resulting in the formation of necrotic lesions and the development of numerous uredinia. The soybean Rpp2 gene confers resistance to specific isolates of P. pachyrhizi. Rpp2-mediated resistance limits the growth of the pathogen and is characterized by the formation of reddish-brown lesions and few uredinia. Using virus-induced gene silencing, we screened 140 candidate genes to identify those that play a role in Rpp2 resistance toward P. pachyrhizi. Candidate genes included putative orthologs to known defense-signaling genes, transcription factors, and genes previously found to be upregulated during the Rpp2 resistance response. We identified 11 genes that compromised Rpp2-mediated resistance when silenced, including GmEDS1, GmNPR1, GmPAD4, GmPAL1, five predicted transcription factors, an O-methyl transferase, and a cytochrome P450 monooxygenase. Together, our results provide new insight into the signaling and biochemical pathways required for resistance against P. pachyrhizi.This article is from Molecular Plant-Microbe Interactions 24 (2011): 194, doi:10.1094/MPMI-08-10-0187. Posted with permission.</p

    Soybean Homologs of MPK4 Negatively Regulate Defense Responses and Positively Regulate Growth and Development

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    Mitogen-activated protein kinase (MAPK) cascades play important roles in disease resistance in model plant species such as Arabidopsis (Arabidopsis thaliana) and tobacco (Nicotiana tabacum). However, the importance of MAPK signaling pathways in the disease resistance of crops is still largely uninvestigated. To better understand the role of MAPK signaling pathways in disease resistance in soybean (Glycine max), 13, nine, and 10 genes encoding distinct MAPKs, MAPKKs, and MAPKKKs, respectively, were silenced using virus-induced gene silencing mediated by Bean pod mottle virus. Among the plants silenced for various MAPKs, MAPKKs, and MAPKKKs, those in which GmMAPK4 homologs (GmMPK4s) were silenced displayed strong phenotypes including stunted stature and spontaneous cell death on the leaves and stems, the characteristic hallmarks of activated defense responses. Microarray analysis showed that genes involved in defense responses, such as those in salicylic acid (SA) signaling pathways, were significantly up-regulated in GmMPK4-silenced plants, whereas genes involved in growth and development, such as those in auxin signaling pathways and in cell cycle and proliferation, were significantly down-regulated. As expected, SA and hydrogen peroxide accumulation was significantly increased in GmMPK4-silenced plants. Accordingly, GmMPK4-silenced plants were more resistant to downy mildew and Soybean mosaic virus compared with vector control plants. Using bimolecular fluorescence complementation analysis and in vitro kinase assays, we determined that GmMKK1 and GmMKK2 might function upstream of GmMPK4. Taken together, our results indicate that GmMPK4s negatively regulate SA accumulation and defense response but positively regulate plant growth and development, and their functions are conserved across plant species.This article is from Plant Physiology 157 (2011): 1363, doi:10.1104/pp.111.185686. Posted with permission.</p

    Vulnerability to climate change of United States marine mammal stocks in the western North Atlantic, Gulf of Mexico, and Caribbean.

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    Climate change and climate variability are affecting marine mammal species and these impacts are projected to continue in the coming decades. Vulnerability assessments provide a framework for evaluating climate impacts over a broad range of species using currently available information. We conducted a trait-based climate vulnerability assessment using expert elicitation for 108 marine mammal stocks and stock groups in the western North Atlantic, Gulf of Mexico, and Caribbean Sea. Our approach combined the exposure (projected change in environmental conditions) and sensitivity (ability to tolerate and adapt to changing conditions) of marine mammal stocks to estimate vulnerability to climate change, and categorize stocks with a vulnerability index. The climate vulnerability score was very high for 44% (n = 47) of these stocks, high for 29% (n = 31), moderate for 20% (n = 22), and low for 7% (n = 8). The majority of stocks (n = 78; 72%) scored very high exposure, whereas 24% (n = 26) scored high, and 4% (n = 4) scored moderate. The sensitivity score was very high for 33% (n = 36) of these stocks, high for 18% (n = 19), moderate for 34% (n = 37), and low for 15% (n = 16). Vulnerability results were summarized for stocks in five taxonomic groups: pinnipeds (n = 4; 25% high, 75% moderate), mysticetes (n = 7; 29% very high, 57% high, 14% moderate), ziphiids (n = 8; 13% very high, 50% high, 38% moderate), delphinids (n = 84; 52% very high, 23% high, 15% moderate, 10% low), and other odontocetes (n = 5; 60% high, 40% moderate). Factors including temperature, ocean pH, and dissolved oxygen were the primary drivers of high climate exposure, with effects mediated through prey and habitat parameters. We quantified sources of uncertainty by bootstrapping vulnerability scores, conducting leave-one-out analyses of individual attributes and individual scorers, and through scoring data quality for each attribute. These results provide information for researchers, managers, and the public on marine mammal responses to climate change to enhance the development of more effective marine mammal management, restoration, and conservation activities that address current and future environmental variation and biological responses due to climate change

    Values used in the NOAA climate change web portal to generate climate exposure maps for 108 marine mammal stocks in the western North Atlantic, Gulf of Mexico, and Caribbean Sea.

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    Values used in the NOAA climate change web portal to generate climate exposure maps for 108 marine mammal stocks in the western North Atlantic, Gulf of Mexico, and Caribbean Sea.</p
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