• Title/Summary/Keyword: resistant development

Search Result 1,403, Processing Time 0.02 seconds

The Effect of Selective Estrogen Receptor Modulators (SERMs) on the Tamoxifen Resistant Breast Cancer Cells

  • Chang, Bo-Yoon;Kim, Sae-Am;Malla, Bindu;Kim, Sung-Yeon
    • Toxicological Research
    • /
    • v.27 no.2
    • /
    • pp.85-93
    • /
    • 2011
  • Selective estrogen receptor modulators (SERMs) are synthetic molecules which bind to estrogen receptors (ER) and can modulate its transcriptional capabilities in different ways in diverse estrogen target tissues. Tamoxifen, the prototypical SERM, is extensively used for targeted therapy of ER positive breast cancers. Unfortunately, the use of tamoxifen is associated with acquired resistance and some undesirable side effects. This study investigated the availability of the conventional SERMs on the TAM-resistance breast cancer cells. SERMs showed more effectiveness in MCF-7 cells than tamoxifen resistant cells, except toremifene and ospemifene. Especially, toremifene was more efficacious in tamoxifen resistant cells than MCF-7. Ospemifene had similar cytotoxic activity on the two types of breast cancers. The other SERMs used in this experiment didn't inhibit efficiently the proliferation of tamoxifen resistant cells. These results support the possibility to usage of toremifene on tamoxifen resistant cancer. The effectiveness by toremifene on tamoxifen resistant cells might be different pathways from the apoptosis and the autophagy. Further study should be needed to elucidate the underlying mechanism of effect of toremifene on tamoxifen resistant cancer.

Breeding of Powdery Mildew Resistant Squash 'Miso'

  • Cho, Myeong-Cheoul;Om, Young-Hyun;Huh, Yun-Chan;Cheong, Seung-Ryong;Kim, Dae-Hyun;Mok, Il-Gin
    • Korean Journal of Organic Agriculture
    • /
    • v.19 no.spc
    • /
    • pp.1-5
    • /
    • 2011
  • A new powdery mildew resistant squash (Cucurbita moschata Duch.) 'Miso' was bred from a cross between powdery mildew resistant true variety 'Sangol' and powdery mildew susceptible inbred line 'Seoulmadi' at National Institute of Horticultural & Herbal Science (NIHHS). The 'Miso' variety was vigorous and highly resistant to powdery mildew. It showed white green fruit color. The variety yielded 21.3MT/ha which is 52% more than control variety.

Biological and Structural Mechanisms of Disease Development and Resistance in Chili Pepper Infected with the Root-knot Nematode

  • Moon, Hyo-Sun;Khan, Zakaullah;Kim, Sang-Gyu;Son, Seon-Hye;Kim, Young-Ho
    • The Plant Pathology Journal
    • /
    • v.26 no.2
    • /
    • pp.149-153
    • /
    • 2010
  • Biological and structural mechanisms of the nematode disease development in chili pepper caused by the root-knot nematode, Meloidogyne incognita, were investigated. Out of 39 chili pepper cultivars/lines tested, six were found resistant, while 33 were susceptible to M. incognita, of which a susceptible cultivar Chilseongcho and three resistant cultivar/lines CM334, 02G132 and 03G53 with different resistance degrees were selected for microscopic studies on the disease development. Gall formation was greatly reduced in the resistant cultivars/lines. Nematode penetration occurred both in the susceptible and resistant chili pepper roots; however, the penetration rates were significantly lowered in the three resistant peppers compared to the susceptible pepper cv. Chilseongcho. In the susceptible pepper, giant cells were extensively formed with no discernible necrosis around the nematode feeding sites. In the highly resistant pepper cultivar CM334, no giant cell was formed, but extensive necrosis formation was observed around the penetrating nematodes. In the other two resistant pepper lines (02G132 and 03G53), both giant cells and prominent necroses were formed, and the necrotic responses appeared to inhibit the further development of giant cells or accelerate their early degeneration. Although the nematode penetration was retarded significantly in the resistant cultivar/lines, all of the above results suggest that the disease resistance of pepper may be related to post-infectional defense mechanisms (nematode growth and development) more than pre-infectional ones (penetration and establishment). Variations in structural modifications in the resistant cultivar/lines may reflect their genetic differences related to the nematode resistance.

Effects of insect-resistant genetically modified rice (Bt-9) cultivation on non-target insect diversity

  • Oh, Sung-Dug;Lim, Myung-Ho;Lee, Bumkyu;Yun, Doh-Won;Sohn, Soo-In;Chang, Ancheol;Park, Soon Ki;Suh, Sang Jae
    • Korean Journal of Agricultural Science
    • /
    • v.45 no.1
    • /
    • pp.28-37
    • /
    • 2018
  • This study was done to develop environmental risk assessments and a biosafety guide for insect-resistant genetically modified rice at a LMO (Living Modified Organism) isolation field. In the LMO quarantine area of Kyungpook National University, the species diversities and population densities of non-target insects found on insect-resistant genetically modified rice (Bt-9) resistant to Cnaphalocrocis medinalis and on non-GM rices (Dongjin and Ilmi) were investigated. The Bt-9 event was therefore evaluated under field conditions to detect possible impacts on the above ground insects and spiders. The study compared transgenic rice and two non-GM reference rices, Ilmi and Dongjin, at Gunwi in Southern Korea in 2016. Each rice was grown on three $18m^2$ plots with a randomized block design. A total of 4,243 individuals from 43 families and 9 orders were collected from the LMO isolation field. In the three types of rice fields, a total of 1,467 individuals from the insect-resistant genetically modified rice (Bt-9), 1,423 individuals from the Ilmi, and 1,353 individuals from the Dongjin were collected, respectively. There was no difference between the population densities of the non-target insect pests, natural enemies and other insects on the insect-resistant genetically modified rice (Bt-9) and non-GM rices. These results provide the diversity and population density of non-target insects for an environment risk assessment survey on insect-resistant genetically modified rice and could be used as a guideline to make a biosafety assessment method for genetically modified crops.

Treatment-Resistant Schizophrenia : Pathophysiology and Treatment (치료 저항성 조현병의 이해와 치료)

  • Kim, Euitae
    • Journal of Korean Neuropsychiatric Association
    • /
    • v.57 no.3
    • /
    • pp.230-234
    • /
    • 2018
  • A large proportion of patients with schizophrenia show a poor response to first-line antipsychotic drugs, which is termed treatment-resistant schizophrenia. Previous studies found that a different neurobiology might underlie treatment-resistant schizophrenia, which necessitates the development of different therapeutic approaches for treating treatment-resistant schizophrenia. This study reviewed previous studies on the pathophysiology of treatment-resistant schizophrenia and the pharmacological intervention, and forthcoming investigations of treatment-resistant schizophrenia are suggested.

Developments of Fire-Resistant Wooden Structural Components and Those Applications to Mid- to High-Rise Buildings in Japan

  • Hanai, Atsunari;Nakai, Masayoshi;Matsuzaki, Hiroyuki;Ohashi, Hirokazu
    • International Journal of High-Rise Buildings
    • /
    • v.9 no.3
    • /
    • pp.221-233
    • /
    • 2020
  • Based on past experiences of natural disasters and fires in Japan, it is stipulated by law that fire-resistant buildings larger than a certain size should be unique in the world. Recent interest in global environmental issues has led to the active introduction of wooden buildings also in Japan, and it is expected that wooden buildings will become larger and higher in size. This paper introduces the background of the development of fire-resistant laminated timber with a "Self-Charring-Stop layer", the contents of this development including other related developments, and the application of these technologies. In addition, towards the realization of much larger and higher buildings in the future, the current problems and issues to be solved are set and the necessity of the future technological development is described. Finally, a conceptual model of wooden high-rise building is proposed, which will be able to be constructed in 2025 by the further technological development.

Evaluation of Resistance to Ralstonia solanacearum in Tomato Genetic Resources at Seedling Stage

  • Kim, Sang Gyu;Hur, On-Sook;Ro, Na-Young;Ko, Ho-Cheol;Rhee, Ju-Hee;Sung, Jung Sook;Ryu, Kyoung-Yul;Lee, Sok-Young;Baek, Hyung Jin
    • The Plant Pathology Journal
    • /
    • v.32 no.1
    • /
    • pp.58-64
    • /
    • 2016
  • Bacterial wilt of tomatoes caused by Ralstonia solanacearum is a devastating disease that limits the production of tomato in Korea. The best way to control this disease is using genetically resistant tomato plant. The resistance degree to R. solanacearum was evaluated for 285 tomato accessions conserved in the National Agrobiodiversity Center of Rural Development Administration. These accessions of tomato were originated from 23 countries. Disease severity of tomato accessions was investigated from 7 days to 14 days at an interval of 7 days after inoculation of R. solanacearum under greenhouse conditions. A total of 279 accessions of tomato germplasm were susceptible to R. solanacearum, resulting in wilt and death in 70 to 90% of these plants. Two tomato accessions were moderately resistant to R. solanacearum. Only four accessions showed high resistance against R. solanacearum. No distinct symptom of bacterial wilt appeared on the resistant tomato germplasms for up to 14 days after inoculation of R. solanacearum. Microscopy of resistant tomato stems infected with R. solanacearum revealed limited bacterial spread with thickening of pit membrane and gum production. Therefore, these four resistant tomato germplasms could be used in tomato breeding program against bacterial wilt.

Antimicrobial Resistance of Vibrio Strains from Brackish Water on the Coast of Gyeongsangnamdo (경남연안 기수지역에서 분리된 비브리오균의 항균제 내성)

  • Oh, Eun-Gyoung;Son, Kwang-Tae;Ha, Kwang-Soo;Yoo, Hyun-Duk;Yu, Hong-Sik;Shin, Soon-Bum;Lee, Hee-Jung;Kim, Ji-Hoe
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.42 no.4
    • /
    • pp.335-343
    • /
    • 2009
  • Antimicrobial resistance patterns of Vibrio species isolated from brackish water in Geoje, Tongyeong and Goseong, Gyeongsangnamdo province into which streams, sewage and leachate all flowed. Only 19 strains (10.7%) of 177 V. parahaemolyticus were susceptible to 15 antimicrobials. 146 strains (69.5%) proved resistant against more than one antimicrobial and 12 strains (6.8%) were multi-drug resistant. The resistance rate of 152 strains were 85.9% against AM and 26.6% against RA, 16.4% against AN, 13.6% against Sand 13.0% against TMP. 86 strains of 129 V. cholerae non-O1 (66.7%) were susceptible to antimicrobials and 31 strains (24.0%) were resistant to more than one antimicrobial and 12 strains (9.3%) were multi-drug resistant. The antimicrobial resistance rate of 129 strains against 15 antimicrobials, with the exception of C, CIP, E and GM, i.e. 11 antimicrobials, was 0.7-16.2%, 16.2% of 129 strains proved resistant against RA and 13.9% against AM, 9.3% against TMP, 7.7% against SXT and 6.9% against TE. 19 of 49 strains of V. mimicus (38.8%) were susceptible to antimicrobials and 31 strains (61.2%) were resistant against more than one antimicrobial; none of the strains were multi-drug resistant. 15 strains of V. mimicus were resistant against only RA, AmC and TE. The resistance rate was 59.2% against RA (highest) 4.1% against AmC and 2.0% against TE.

Evaluation and Development of Corrosion Resistant Materials for Smokestacks

  • Ebara, Ryuichiro
    • Corrosion Science and Technology
    • /
    • v.6 no.4
    • /
    • pp.211-218
    • /
    • 2007
  • In this paper, evaluation and development of corrosion resistant materials for smokestacks is summarized mainly on the basis of the author's experimental results. Operating environments of smokestacks and the problems of conventional lining materials for smokestacks are described briefly. The emphasis is focused upon the evaluation and development of recently developed corrosion resistant steels such as YUS260 for heavy oil fired smokestacks, WELACC5 for LNG fired smokestacks and NSL310MoCu Clad steel for coal fired smokestacks. Corrosion resistance of these steels under laboratory corrosion testing environments and actual environments are evaluated. Finally future problems of corrosion resistant materials for smokestacks are touched on briefly.

Effect of insect-resistant genetically engineered (Bt-T) rice and conventional cultivars on the brown planthopper (Nilaparvata lugens Stål)

  • Sung-Dug, Oh;Eun Ji, Bae;Kijong, Lee;Soo-Yun, Park;Myung-Ho, Lim;Doh-Won, Yun;Seong-Kon, Lee;Gang-Seob, Lee;Soon Ki, Park;Jae Kwang, Kim;Sang Jae, Suh
    • Korean Journal of Agricultural Science
    • /
    • v.49 no.3
    • /
    • pp.511-520
    • /
    • 2022
  • Insect-resistant transgenic rice (Bt-T) expresses a toxic protein (mcry1Ac1) derived from the soil bacterium Bacillus thuringiensis found in the rice cultivar Dongjin with an insecticidal property against rice leaf roller (Cnaphalocrocis medinalis). In this study, to investigate the impact of Bt-T on non-target organisms, the feed and oviposition preferences and biological parameters of brown planthopper (Nilaparvata lugens Stål) were comparatively analyzed in four rice cultivars: Dongjin (parent variety), Ilmi (reference cultivar), Chinnong (brown planthopper resistant cultivar) and Bt-T. In the Bt-T and Dongjin cultivars, the feed preferences were 32.4 ± 8.3 and 34.1 ± 6.8%, and the oviposition preferences were 32.5 ± 5.1 and 30.0 ± 5.3% respectively, and there was no statistical significance between these rices. Additionally, in the Bt-T and Dongjin cultivars, the total lifespans from egg to adult were 39.5 ± 6.9 and 40.0 ± 5.8 days, and the weights of adult females were 1.78 ± 0.14 and 1.72 ± 0.16 mg, respectively. Therefore, there was no statistical difference in the biological parameters between these two varieties. Overall, the results indicate that the insect-resistant transgenic rice (Bt-T) did not negatively affect the reproduction and life cycle of brown planthopper, a non-target organism.