• Title/Summary/Keyword: Laser capture microscope

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Comparative Study of p53 Mutation and Oncoprotein Expression in Gastric Adenocarcinoma (미세절편으로 얻은 위암 조직세포에서 p53 유전자의 돌연변이와 종양단백 발현에 관한 연구)

  • Kim Chul;Joo Jai Kyun;Choi Chan;Kim Young Jin
    • Journal of Gastric Cancer
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    • v.3 no.3
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    • pp.145-150
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    • 2003
  • Purpose: The p53 tumor suppressor gene is believed to play a pivotal role in preventing the uncontrolled cellular growth characteristic of cancer. Mutation of the p53 gene represent one of the most common genetic alterations in human cancers, and the acquisition of such defects is strongly associated with tumor progression and metastasis. The aim of this study was to evaluate the relation between p53 immunoreactivity and the mutation of p53 gene in gastric adenocarcinoma obtained by laser capture microscope. Materials and Methods: Formalin fixed paraffin embedded tissue specimens were obtained from 20 patients who underwent surgery for gastric cancer. According to UICC TNM system, 3 of the cases were Ia, 2 cases II, 4 cases IIIa, 5 cases IIIb, and 6 cases IV. Results: Immunohistochemical staining revealed eight cases as negative (less than $10\%$), twelve cases as postive (more than $10\%$). The locations of mutations were as follows; 7 cases had point mutation at exon 4, and 3 cases point mutation at exon 8. There was no mutation at exon 5, 6, 7 and 9. The mutation was observed in 1 case out of 8 p53 oncoprotein negative cases, and 7 cases out of 12 p53 positive cases. The mutation was more common in p53 positive cases (P<0.05), However, there was no significant correlation between p53 mutation observed by DNA sequencing after laser capture microdissection and expression of p53 oncoprotein. Conclusion: These result suggest that he expression of p53 oncoprotein not to be related to the mutation of p53 gene at exons 4 through 9 in gastric cancer.

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Sediment monitoring for hydro-abrasive erosion: A field study from Himalayas, India

  • Rai, Anant Kr.;Kumar, Arun
    • International Journal of Fluid Machinery and Systems
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    • v.10 no.2
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    • pp.146-153
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    • 2017
  • Sediment flow through hydropower components causes hydro-abrasive erosion resulting in loss of efficiency, interruptions in power production and downtime for repair/maintenance. Online instruments are required to measure/capture the variations in sediment parameters along with collecting samples manually to analyse in laboratory for verification. In this paper, various sediment parameters viz. size, concentration (TSS), shape and mineral composition relevant to hydro-abrasive erosion were measured and discussed with respect to a hydropower plant in Himalayan region, India. A multi-frequency acoustic instrument was installed at a desilting chamber to continuously monitor particle size distribution (PSD) and TSS entering the turbine during 27 May to 6 August 2015. The sediment parameters viz. TSS, size distribution, mineral composition and shape entering the turbine were also measured and analysed, using manual samples collected twice daily from hydropower plant, in laboratory with instruments based on laser diffraction, dynamic digital image processing, gravimetric method, conductivity, scanning electron microscope, X-ray diffraction and turbidity. The acoustic instrument was able to capture the variation in TSS; however, significant deviations were found between measured mean sediment sizes compared to values found in the laboratory. A good relation was found for turbidity ($R^2=0.86$) and laser diffraction ($R^2=0.93$) with TSS, which indicated that turbidimeter and laser diffraction instrument can be used for continuous monitoring of TSS at the plant. Total sediment load passed through penstock during study period was estimated to be 15,500 ton. This study shall be useful for researchers and hydropower managers in measuring/monitoring sediment for hydro-abrasive erosion study in hydropower plants.

Characterization of Invading Glioma Cells Using Molecular Analysis of Leading-Edge Tissue

  • Kim, Cheol-Soo;Jung, Shin;Jung, Tae-Young;Jang, Woo-Youl;Sun, Heung-Suk;Ryu, Hyang-Hwa
    • Journal of Korean Neurosurgical Society
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    • v.50 no.3
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    • pp.157-165
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    • 2011
  • Objective : We have introduced a method of characterization of invading glioma cells by using molecular analysis of marginal invading tumor cells and molecular profiles of glioma tumor margin. Methods : Each of tumor core and marginal tissues was obtained in 22 glioma patients. Tumor core cells and marginal cells from each glial tumor were collected by laser capture microdissection or intraoperative microdissection under the operating microscope. Expression of MMP-2, MMP-9, CD44 and RHAMM mRNA by invading glioma cells compared with tumor core was confirmed by realtime-PCR of twenty-four glioma specimens. Clinical data also were reviewed for invasion and recurrence pattern of the gliomas radiologically and invasive rim pattern microscopically. Results : Overall results of the molecular analysis showed that relative overexpression of MMP-2, MMP-9 and RHAMM were noted at the invasive edge of human glioma specimens comparing to the tumor core but CD44 was highly expressed in the tumor core comparing to the margin. High marginal expression of MMP-2 and MMP-9 were noted in poorly ill-defined margin on the pathological finding. High marginal expression of CD44 and MMP-2 were demonstrated in the midline cross group on the radiological review, and that of RHAMM and MMP-2 were showed in the aggressive recurrence group. High expression of MMP-2 seems to be involved in the various invasion-related phenomenons. Conclusion : Up-regulation of MMP-2, MMP-9, CD44 and RHAMM was noted in invasive edge of gliomas according to the various clinical situations.