Time-Staged Gamma Knife Stereotactic Radiosurgery for Large Cerebral Arteriovenous Malformations: A Preliminary Report

ObjectiveWe retrospectively analyzed our experience with time-staged gamma knife stereotactic radiosurgery (GKS) in treating large arteriovenous malformation(AVM)s;≥ 10 cm³).MethodsForty-five patients who underwent time-staged GKS (2-stage, n = 37;3-stage,n = 8) between March 1998 and December 2011 were included. The mean volume treated was 20.42±6.29 cm³ (range, 10.20–38.50 cm³). Obliteration rates of AVMs and the associated complications after GKS were evaluated.ResultsMean AVM volume (and median marginal dose) at each GKS session in the 37 patients who underwent 2-stage GKS was 19.67±6.08 cm³ (13 Gy) at session 1 and 6.97±6.92 cm³ (17 Gy) at session 2. The median interval period was 39 months. After follow-up period of 37 months, the complete obliteration rate was 64.9%. The mean AVM volume (and median marginal dose) at each GKS session in the 8 patients who underwent 3-stage GKS was 23.90±6.50 cm³ (12.25 Gy), 19.43±7.46 cm³ (13.5 Gy), 7.48±6.86 cm³ (15.5 Gy) at session 1, 2, and 3, respectively. The median interval duration between each GKS session was 37.5 and 38 months, respectively. After a median follow-up period of 47.5 months, 5 patients (62.5%) achieved complete obliteration. Postradiosurgical hemorrhage developed in 5 patients (11.1%) including one case of major bleeding and 4 cases of minor bleeding. No patient suffered from clinically symptomatic radiation necrosis following radiation.ConclusionTime-staged GKS could be an effective and safe treatment option in the management of large AVMs.     

Constitutive expression of a fungus-inducible carboxylesterase improves disease resistance in transgenic pepper plants

Main conclusion

Resistance against anthracnose fungi was enhanced in transgenic pepper plants that accumulated high levels of a carboxylesterase, PepEST in anthracnose-susceptible fruits, with a concurrent induction of antioxidant enzymes and SA-dependent PR proteins. A pepper esterase gene (PepEST) is highly expressed during the incompatible interaction between ripe fruits of pepper (Capsicum annuum L.) and a hemibiotrophic anthracnose fungus (Colletotrichum gloeosporioides). In this study, we found that exogenous application of recombinant PepEST protein on the surface of the unripe pepper fruits led to a potentiated state for disease resistance in the fruits, including generation of hydrogen peroxide and expression of pathogenesis-related (PR) genes that encode mostly small proteins with antimicrobial activity. To elucidate the role of PepEST in plant defense, we further developed transgenic pepper plants overexpressing PepEST under the control of CaMV 35S promoter. Molecular analysis confirmed the establishment of three independent transgenic lines carrying single copy of transgenes. The level of PepEST protein was estimated to be approximately 0.002 % of total soluble protein in transgenic fruits. In response to the anthracnose fungus, the transgenic fruits displayed higher expression of PR genes, PR3, PR5, PR10, and PepThi, than non-transgenic control fruits did. Moreover, immunolocalization results showed concurrent localization of ascorbate peroxidase (APX) and PR3 proteins, along with the PepEST protein, in the infected region of transgenic fruits. Disease rate analysis revealed significantly low occurrence of anthracnose disease in the transgenic fruits, approximately 30 % of that in non-transgenic fruits. Furthermore, the transgenic plants also exhibited resistance against C. acutatum and C. coccodes. Collectively, our results suggest that overexpression of PepEST in pepper confers enhanced resistance against the anthracnose fungi by activating the defense signaling pathways.

     

Insect distribution in response to climate change based on a model: Review of function and use of CLIMEX

The significant dependence of agricultural productivity on pest control requires pest distribution predictions at an early stage of pest invasion. Because pest cycles are critically affected by climate, climate is one of the most important factors for predicting an invasive pest. CLIMEX is a highly effective tool that can predict potential geographical species distributions, and test the regional suitability for a target species' habitat based on data including climate change scenarios. CLIMEX has been recently used in Europe, North America, China and Australia, among others. However, for modeling species distributions in Korea, the use of the model has been limited to date. This study aimed to first introduce the function and application of CLIMEX by reviewing important studies using this model. Second, we investigated previous studies using the model simulation to demonstrate the practical applicability of CLIMEX for the agricultural sector, and its use in forecasting.