• 제목/요약/키워드: Radiation biology

검색결과 443건 처리시간 0.025초

분생포자수 및 영양상태가 대두갈색무늬병균의 분생포자 발아에 미치는 영향 (Effect of Conidial Number and Nutrition on the Germination of Conidia in Septoria glycines)

  • 오정행;정후섭
    • 한국응용곤충학회지
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    • 제23권1호
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    • pp.61-67
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    • 1984
  • 대두갈색무늬병균의 포자발아(分生胞子發芽) 미치는 외부영양공급(外部營養供給) 및 self-inhibitor의 영향(影響)을 조사하여 다음과 같은 결과(結果)를 얻었다. 1. 갈색무늬병균의 포자발아율은 감자한천배지 및 대두잎조각을 첨가한 증류수에서는 양호하였으나 살균된 증류수에서는 극히 불량하였다. 2. 갈색무늬병균의 포자발아에는 탄소원의 외부공급이 절대 필요한 것으로 보였으며 인산, 가리 등은 큰 영향이 없는 것으로 보였다. 3. 탄소원으로서는 가용성 전분이 가장 효과적이었고 다음이 포도당, 유당 등이었으며 포도당의 경우 $5\times10^{-2}mol$ 농도에서 가장 높은 발아율을 보였다. 4. 포자발아율은 포자밀도가 높을수록 현저히 감소하여 포자농도 $10,000conidia/mm^2$ 이상에서는 거의 발아하지 않는 것으로 보아 self-inhibitor가 존재하는 것으로 보였다. 5. 기질(基質)을 세척한 포자의 발아율은 세척하지 않은 포자의 발아율에 비해 낮았으며 이러한 현상은 포자농도가 $2,000conidia/mm^2 $ 이상으로 증가할 때 더욱 현저하였고 건조된 한천배양기위에는 발아율 감소가 현저하였다.

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Protective Effect of Panax ginseng extract on Renal Functions Altered by Mercuric Chloride in Albino Rats

  • Saxena, Prabhu-N.;Mahour, K.;Kumar, Ashok
    • Journal of Ginseng Research
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    • 제30권3호
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    • pp.100-105
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    • 2006
  • Liver and kidney are specific organs which play an active role in biotransformation and detoxification mechanisms. Ant adverse effect of chemicals or heavy metal can cause the delay or fade in these mechanisms. Present study was designed to find out the protective effect of Panax ginseng extract on renal functions altered by mercuric chloride (heavy metal) in albino rat. Fifty albino rats were divided into 10 groups. Five groups for acute study and five groups for sud-acute study viz. control group (Tween 20 and distilled water), mercuric chloride treated group (0.926 mg/kg body wt. for acute and 0.044 mg/kg body wt. for sub-acute group after calculated $LD_{50}$ (9.26 mg/kg body wt.) by probit analysis (Finney, 1971), Panax ginseng extract treated group (10 mg/kg body wt. for acute and sub-acute sets), mercuric chloride treated followed by Panax ginseng extract and Panax ginseng extract followed by mercuric chloride group. All doses were given orally by gavage tube. The result revealed that the serum urea and creatinine significantly increased in mercuric chloride treated group, while significantly decreased (p<0.01) in Panax ginseng extract group after acute and sub-acute treatment. The biochemical estimation is also confirmed by nephropathological aspect. However, the Panax ginseng extract treated followed by mercuric chloride group is more prominent than the mercuric chloride treated followed by Panax ginseng extract group. It can be concluded that Panax ginseng extract had a protective nature on renal functions against mercuric chloride toxicity in albino rats.

Panax ginseng Extract as Protectant in Mercuric Chloride Induced Alterations in Protein Biochemistry in the Serum of Albino Rats

  • Mahour, K.;Saxena, Prabhu-N.;Kumar, Ashok
    • Journal of Ginseng Research
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    • 제30권3호
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    • pp.106-111
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    • 2006
  • Adverse changes in individual's biochemistry under heavy metal stress are directly linked with its metabolic activity and health status. The present investigation highlights the differences in protecting role of Panax ginseng extract against mercuric chloride induced alterations in serum proteins. The assessment was based on dividing fifty albino rats into two sets, one for acute and the other for sub-acute study. All the sets had five groups with five albino rats in each i.e. control group, mercuric chloride treated group, Panax ginseng extract treated group, mercuric chloride followed by Panax ginseng extract treated group and Panax ginseng extract followed by mercuric chloride treated group. Mercuric chloride was given orally 0.926 mg/kg body weight for acute set and 0.044 mg/kg body weight for sub-acute set after LD50 (9.26 mg/kg body weight) determination by probitt analysis. 10 mg/kg body weight Panax ginseng extract was given in both acute and sub-acute sets after incorporating safety trials. The control group received tween-20 and distilled water only. The result exhibited significantly reduction (P<0.01) in serum protein, albumin and globulin following mercuric chloride intoxication whereas significant (P<0.01) enhancement in other groups with Panax ginseng extract as an ingredient confirming its protective role. All serum samples were also electrophoresed in 10% SDS with standard marker using discontinuous buffering system. Gradual disappearance of alpha-2 and beta-1 globulin bands from electrophoretic pattern was observed, while a single sharp band was observed between beta-2 and gamma globulin in serum protein pattern of acutely mercuric chloride treated rats. However, this band could not be visualized in sub-acute studies. Panax ginseng extract exhibits a better protection after acute intoxication.

BK Knockout by TALEN-Mediated Gene Targeting in Osteoblasts: KCNMA1 Determines the Proliferation and Differentiation of Osteoblasts

  • Hei, Hongya;Gao, Jianjun;Dong, Jibin;Tao, Jie;Tian, Lulu;Pan, Wanma;Wang, Hongyu;Zhang, Xuemei
    • Molecules and Cells
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    • 제39권7호
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    • pp.530-535
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    • 2016
  • Large conductance calcium-activated potassium (BK) channels participate in many important physiological functions in excitable tissues such as neurons, cardiac and smooth muscles, whereas the knowledge of BK channels in bone tissues and osteoblasts remains elusive. To investigate the role of BK channels in osteoblasts, we used transcription activator-like effector nuclease (TALEN) to establish a BK knockout cell line on rat ROS17/2.8 osteoblast, and detected the proliferation and mineralization of the BK-knockout cells. Our study found that the BKknockout cells significantly decreased the ability of proliferation and mineralization as osteoblasts, compared to the wild type cells. The overall expression of osteoblast differentiation marker genes in the BK-knockout cells was significantly lower than that in wild type osteoblast cells. The BK-knockout osteoblast cell line in our study displays a phenotype decrease in osteoblast function which can mimic the pathological state of osteoblast and thus provide a working cell line as a tool for study of osteoblast function and bone related diseases.

Identification and Characterization of a Putative Basic Helix-Loop-Helix (bHLH) Transcription Factor Interacting with Calcineurin in C. elegans

  • Lee, Soo-Ung;Song, Hyun-Ok;Lee, Wonhae;Singaravelu, Gunasekaran;Yu, Jae-Ran;Park, Woo-Yoon
    • Molecules and Cells
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    • 제28권5호
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    • pp.455-461
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    • 2009
  • Calcineurin is a $Ca^{2+}$/Calmodulin activated Ser/Thr phosphatase that is well conserved from yeast to human. It is composed of catalytic subunit A (CnA) and regulatory subunit B (CnB). C. elegans homolog of CnA and CnB has been annotated to tax-6 and cnb-1, respectively and in vivo function of both genes has been intensively studied. In C. elegans, calcineurin play roles in various signaling pathways such as fertility, movement, body size regulation and serotonin-mediated egg laying. In order to understand additional signaling pathway(s) in which calcineurin functions, we screened for binding proteins of TAX-6 and found a novel binding protein, HLH-11. The HLH-11, a member of basic helix-loop-helix (bHLH) proteins, is a putative counterpart of human AP4 transcription factor. Previously bHLH transcription factors have been implicated to regulate many developmental processes such as cell proliferation and differentiation, sex determination and myogenesis. However, the in vivo function of hlh-11 is largely unknown. Here, we show that hlh-11 is expressed in pharynx, intestine, nerve cords, anal depressor and vuvla muscles where calcineurin is also expressed. Mutant analyses reveal that hlh-11 may have role(s) in regulating body size and reproduction. More interestingly, genetic epistasis suggests that hlh-11 may function to regulate serotoninmediated egg laying at the downstream of tax-6.

Current Radiopharmaceuticals for Positron Emission Tomography of Brain Tumors

  • Jung, Ji-hoon;Ahn, Byeong-Cheol
    • Brain Tumor Research and Treatment
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    • 제6권2호
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    • pp.47-53
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    • 2018
  • Brain tumors represent a diverse spectrum of histology, biology, prognosis, and treatment options. Although MRI remains the gold standard for morphological tumor characterization, positron emission tomography (PET) can play a critical role in evaluating disease status. This article focuses on the use of PET with radiolabeled glucose and amino acid analogs to aid in the diagnosis of tumors and differentiate between recurrent tumors and radiation necrosis. The most widely used tracer is $^{18}F$-fluorodeoxyglucose (FDG). Although the intensity of FDG uptake is clearly associated with tumor grade, the exact role of FDG PET imaging remains debatable. Additionally, high uptake of FDG in normal grey matter limits its use in some low-grade tumors that may not be visualized. Because of their potential to overcome the limitation of FDG PET of brain tumors, $^{11}C$-methionine and $^{18}F$-3,4-dihydroxyphenylalanine (FDOPA) have been proposed. Low accumulation of amino acid tracers in normal brains allows the detection of low-grade gliomas and facilitates more precise tumor delineation. These amino acid tracers have higher sensitivity and specificity for detecting brain tumors and differentiating recurrent tumors from post-therapeutic changes. FDG and amino acid tracers may be complementary, and both may be required for assessment of an individual patient. Additional tracers for brain tumor imaging are currently under development. Combinations of different tracers might provide more in-depth information about tumor characteristics, and current limitations may thus be overcome in the near future. PET with various tracers including FDG, $^{11}C$-methionine, and FDOPA has improved the management of patients with brain tumors. To evaluate the exact value of PET, however, additional prospective large sample studies are needed.

Anastral Spindle 3/Rotatin Stabilizes Sol narae and Promotes Cell Survival in Drosophila melanogaster

  • Cho, Dong-Gyu;Lee, Sang-Soo;Cho, Kyung-Ok
    • Molecules and Cells
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    • 제44권1호
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    • pp.13-25
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    • 2021
  • Apoptosis and compensatory proliferation, two intertwined cellular processes essential for both development and adult homeostasis, are often initiated by the mis-regulation of centrosomal proteins, damaged DNA, and defects in mitosis. Fly Anastral spindle 3 (Ana3) is a member of the pericentriolar matrix proteins and known as a key component of centriolar cohesion and basal body formation. We report here that ana3m19 is a suppressor of lethality induced by the overexpression of Sol narae (Sona), a metalloprotease in a disintegrin and metalloprotease with thrombospondin motif (ADAMTS) family. ana3m19 has a nonsense mutation that truncates the highly conserved carboxyl terminal region containing multiple Armadillo repeats. Lethality induced by Sona overexpression was completely rescued by knockdown of Ana3, and the small and malformed wing and hinge phenotype induced by the knockdown of Ana3 was also normalized by Sona overexpression, establishing a mutually positive genetic interaction between ana3 and sona. p35 inhibited apoptosis and rescued the small wing and hinge phenotype induced by knockdown of ana3. Furthermore, overexpression of Ana3 increased the survival rate of irradiated flies and reduced the number of dying cells, demonstrating that Ana3 actively promotes cell survival. Knockdown of Ana3 decreased the levels of both intra- and extracellular Sona in wing discs, while overexpression of Ana3 in S2 cells dramatically increased the levels of both cytoplasmic and exosomal Sona due to the stabilization of Sona in the lysosomal degradation pathway. We propose that one of the main functions of Ana3 is to stabilize Sona for cell survival and proliferation.

인유두종바이러스 연관 구인두암의 치료 약화 전략: 보고된 결과를 중심으로 분석 (Treatment Deintensification for Human Papillomavirus-Associated Oropharyngeal Cancer: Focused Review of Published Data)

  • 김진호
    • 대한두경부종양학회지
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    • 제38권2호
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    • pp.7-13
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    • 2022
  • Human papillomavirus (HPV) is a causative agent for a subset of oropharyngeal cancer (OPC). The current standard of care (SOC) for locally advanced OPC is 70 Gy definitive radiotherapy (RT) concurrent with cisplatin, which entails significant proportions of acute and late grade 3 or higher toxicities. Accordingly, discovery of favorable prognosis of HPV-related OPC has led to enthusiasm to attenuate subspecialties therapy in multidisciplinary treatment. Diverse deintensification strategies were investigated in multiple phase 2 trials with an assumption that attenuated treatments result in comparable oncologic outcome and less toxicities compared with SOC. Several trials on chemotherapy deintensification revealed that concomitant administration of cisplatin is not to be omitted or substituted for cetuximab without compromising progression-free survival or local control. A transoral robotic surgery (TORS) is investigated as alternative local treatment, but TORS plus SOC or mild deintensified adjuvant RT showed similar toxicities and inferior oncologic outcomes compared with SOC definitive RT or moderately deintensified RT. However, it has been reported that TORS plus deintensified 30-36 Gy adjuvant RT results in excellent outcome and less late toxicity compared with SOC adjuvant RT. Several phase 2 trials reported apparently equivalent progression-free survival and local control and similar adverse effects with moderately deintensified 60 Gy RT compared with SOC 70 Gy RT. Further dose reduction below 60 Gy has been investigated using biology-directed approaches, which use response to induction chemotherapy or metabolic images to triage HPV-positive OPC for deintensified RT. In summary, these trials provide valuable insights for future directions. Available evidence consistently showed that moderately deintensified RT is effective and safe for HPV-positive OPC in both definitive and adjuvant settings. Concurrent cisplatin remains an essential component without which progression-free survival is significantly compromised for advanced HPV-positive OPC. A simple incorporation of TORS to SOC may be detrimental for oncologic outcome without anticipated toxicity reduction. Given the lack of level 1 evidence, it is prudent to curb an unjustified deviation from the current SOC and limit any deintensified strategies to clinical trials and adhere to the current SOC.

Resistance Induction by Salicylic Acid Formulation in Cassava Plant against Fusarium solani

  • Saengchan, Chanon;Phansak, Piyaporn;Thumanu, Kanjana;Siriwong, Supatcharee;Le Thanh, Toan;Sangpueak, Rungthip;Thepbandit, Wannaporn;Papathoti, Narendra Kumar;Buensanteai, Natthiya
    • The Plant Pathology Journal
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    • 제38권3호
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    • pp.212-219
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    • 2022
  • Fusarium root rot caused by the soil-borne fungus Fusarium solani is one of the most important fungal diseases of cassava in Thailand, resulting in high yield losses of more than 80%. This study aimed to investigate if the exogenous application of salicylic acid formulations (Zacha) can induce resistance in cassava against Fusarium root rot and observe the biochemical changes in induced cassava leaf tissues through synchrotron radiation based on Fourier-transform infrared (SR-FTIR) microspectroscopy. We demonstrated that the application of Zacha11 prototype formulations could induce resistance against Fusarium root rot in cassava. The in vitro experimental results showed that Zacha11 prototype formulations inhibited the growth of F. solani at approximately 34.83%. Furthermore, a significant reduction in the disease severity of Fusarium root rot disease at 60 days after challenge inoculation was observed in cassava plants treated with Zacha11 at a concentration of 500 ppm (9.0%). Population densities of F. solani were determined at 7 days after inoculation. Treatment of the Zacha11 at a concentration of 500 ppm resulted in reduced populations compared with the distilled water control and differences among treatment means at each assay date. Moreover, the SR-FTIR spectral changes of Zacha11-treated epidermal tissues of leaves had higher integral areas of lipids, lignins, and pectins (1,770-1,700/cm), amide I (1,700-1,600/cm), amide II (1,600-1,500/cm), hemicellulose, lignin (1,300-1,200/cm), and cellulose (1,155/cm). Therefore, alteration in defensive carbohydrates, lipids, and proteins contributed to generate barriers against Fusarium invasion in cassava roots, leading to lower the root rot disease severity.

Effects of biostimulants, AMPEP and Kelpak on the growth and asexual reproduction of Pyropia yezoensis (Bangiales, Rhodophyta) at different temperatures

  • Sook Kyung Shin;Qikun Xing;Ji-Sook Park;Charles Yarish;Fanna Kong;Jang K. Kim
    • ALGAE
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    • 제39권1호
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    • pp.31-41
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    • 2024
  • Acadian marine plant extract powder (AMPEP) and Kelpak are commercial biostimulants derived from brown algae Ascophyllum nodosum. This study was to determine if AMPEP and Kelpak can induce thermal resistance in Pyropia yezoensis. P. yezoensis blades were exposed to different concentrations (control: 0, low: 0.001, high: 1 ppm) of AMPEP and Kelpak at 10℃ for 6 and 7 days, respectively. Those blades were then cultivated in von Stosch enriched seawater medium at different temperatures (10, 15, 20, and 25℃) with 12 : 12 L : D photoperiod and 100 µmol m-2 s-1 of photosynthetically active radiation for additional 15 days. Results showed that P. yezoensisreproduced archeospores at 20 and 25℃ at all biostimulant conditions within 15 days. At lower temperatures (10 and 15℃), only AMPEP-treated P. yezoensis reproduced archeospores. P. yezoensis exposed to 1 ppm Kelpak exhibited higher phycoerythrin and phycocyanin contents than control and 0.001 ppm conditions at 15℃. AMPEP-treated conditions showed higher phycoerythrin and phycocyanin contents than control at 10℃. These results suggest that AMPEP and Kelpak may not enhance the thermal resistance of P. yezoensis. However, AMPEP stimulated archeospores release at lower temperatures. The treatment of AMPEP and Kelpak also increased the pigment contents in P. yezoensis. These results suggest that the use of seaweed-derived biostimulants can provide some economic benefits in P. yezoensis aquaculture. The enhancement of archeospores formation by AMPEP at lower temperature may also increase the productivity since Pyropia farming relies on the accumulation of secondary seedings via asexual reproduction.