• 제목/요약/키워드: Expression rate

검색결과 1,969건 처리시간 0.027초

유전자 발현 데이터에 대한 다중검정법 비교 및 분석 (Comparison and analysis of multiple testing methods for microarray gene expression data)

  • 서수민;김태훈;김재희
    • Journal of the Korean Data and Information Science Society
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    • 제25권5호
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    • pp.971-986
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    • 2014
  • 동시에 여러 개의 가설검정 수행시 귀무가설이 참일 경우 귀무가설을 기각할 확률이 커지는 문제가 발생한다. 이러한 다중검정 문제 해결을 위해 여러 연구에서는 가설검정시 필요한 집단별 오류율(FWER; family-wise error rate), 위발견율 (FDR; false discovery rate) 또는 위비발견율 (FNR; false nondiscovery rate) 과 통계량을 고려하여 검정력을 높이고자 하였다. 본 연구에서는 T 통계량, 수정된 T 통계량, 그리고 LPE (local pooled error) 통계량 기반 P값을 이용한 Bonferroni (1960) 방법, Holm (1979) 방법, Benjamini와 Hochberg (1995) 방법과 Benjamini와 Yekutieli (2001) 방법 그리고 Z 통계량 기반 Sun과 Cai (2007) 방법을 고찰하고 모의실험을 통해 다중검정 능력을 비교하였다. 또한 실제 데이터로 애기장대 유전자 발현 데이터에 대해 여러 가지 다중검정법을 통해 유의한 유전자들을 선별하였다.

분노표현 양식과 스트레스 노출이 심박변이도에 미치는 영향 (The Effect of Anger Expression Style and Stress on Heart Rate Variablity)

  • 김현도;임명호;김현우;이석범;이경규;김현주;노상철;백기청
    • 대한불안의학회지
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    • 제5권1호
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    • pp.21-28
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    • 2009
  • Objective : Using patterns of change in heart rate variability (HRV), we investigated the effects of stress exposure and type of anger expression on cardiovascular diseases. Methods : Eighty-nine medical students were evaluated by STAXI-K, BDI, BAI, and measured HRV. According to the scores of anger expression questions in STAXI-K, objects are comparted to three groups. Each group is compared with others on the levels of depression, anxiety and HRV. Additionally objects are divided into two groups of functional anger expression group and dysfunctional anger expression group, and each group also divided into two groups, depending on the exposure of stressful situation or not. Members who took part in the stress exposure groups, they've got a serial arithmetic process for five minutes. We surveyed patterns of HRV in 4 each groups and estimated interactions between existence of stressful situation or type of anger expression and HRV. Results : Irrespective of stress manipulation, the dysfunctional anger expression group showed a marked increase in the LF/HF ratio in comparison to the functional anger expression group. Also, under conditions of stress manipulation, the stress exposure group exhibited a relatively increased level of TP. It can't be discriminated any correlations between stress manipulation and type of anger expression. Conclusion : Both of them, exposure to the stressful situation and type of anger expression, have influence on cardiovascular diseases. By controlling anger and way of express that, it is possible to diminish the incidence of cardiovascular diseases.

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표정 정규화를 통한 얼굴 인식율 개선 (Improvement of Face Recognition Rate by Normalization of Facial Expression)

  • 김진옥
    • 정보처리학회논문지B
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    • 제15B권5호
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    • pp.477-486
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    • 2008
  • 얼굴의 기하학적 특징이 변하여 생기는 표정은 얼굴 인식 시스템의 인식 결과에 다양한 영향을 끼친다. 얼굴 인식율을 개선하기 위해 본 연구에서는 인식 대상 얼굴과 참조 얼굴 사이의 표정 차이를 줄이는 방법으로 얼굴 표정 정규화를 제안한다. 본 연구에서는 대형의 이미지 데이터베이스를 구축하지 않고도 한 개의 정지 이미지에 일반적인 얼굴 근육 모델을 이용하는 접근 방식을 제시하여 얼굴 표정 모델링과 정규화를 처리한다. 첫 번째 방식은 본능적으로 변하는 얼굴 표정의 생물학적 모델을 구축하기 위해 선형 근육 모델의 기하학적 계수를 예측하는 것이다. 두 번째 방식은 RBF(Radial Basis Function)기반의 보간과 와핑을 통해 주어진 표정에 따라 얼굴 근육 모델을 무표정한 얼굴로 정규화한 것이다. 실험 결과, 기저얼굴 방식, 지역 이진 패턴 방식, 회색조 상관측정 방식과 같은 얼굴 인식 과정의 전처리 단계로 본 연구의 표정 정규화 과정을 적용하면 정규화를 거치지 않은 것보다 더 높은 인식율을 보인다.

두경부 편평세포암종에서 인유두종 바이러스와 p53과 Proliferating Cell Nuclear Antigen 발현의 임상적 의의 (The Clinical Implication of Human Papilloma Virus, p53 and Proliferating Cell Nuclear Antigen Expression in Head and Neck Squamous Cell Carcinoma)

  • 김종수;김민식;박경호;선동일;박동선;조승호
    • 대한기관식도과학회지
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    • 제7권2호
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    • pp.152-160
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    • 2001
  • The presence of HPV DNA and the expression of p53 protein and proliferating cell nuclear antigen(PCNA) in head and neck squamous cell carcinoma were determined to evaluate the relationship of these factors and their association with their pathologic stages and cervical lymph node metastasis. Among 65 patients the presence of HPV DNA was found in 12 cases(18.5%), p53 was found positive in 32 cases(49.2%) and expression of PCNA was observed in 24 cases(36.9%). The expression of PCNA was more frequent in the HPV positive cancers compared with the HPV negative ones(p =0.0018), and p53 revealed its higher rate of cooccurrence with the expression of PCNA(p =0.008), which might suggest that PCNA expression has a positive relationship with HPV and p53 mutation in head and neck cancer. There might be inverse relationship between HPV and p53 mutation(p =0.063), but 3 cases showed both HPV DNA positivity and p53 expression. HPV was detected at a higher rate in the early pathologic stages than in the advanced stages of cancer, and p53 expression was more frequently found in the advanced stages(p =0.044). These results suggests that HPV and p53 mutation might have different etiologic roles in the development of head and neck cancer, or cases with p53 mutation might have more aggressive behavior. PCNA expression showed no difference between early and late stages of cancer, and between cases with and without cervical lymph node metastasis.

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Expression of Vimentin and Ki-67 Proteins in Cervical Squamous Cell Carcinoma and their Relationships with Clinicopathological Features

  • Yu, Jian-Qin;Zhou, Qing;Zheng, Yun-Fei;Bao, Ying
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권10호
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    • pp.4271-4275
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    • 2015
  • Objectives: To investigate the expression of vimentin and Ki-67 proteins in cervical squamous cell carcinoma (CSCC) and their relationships with patient clinicopathological features. Materials and Methods:Fifty-seven CSCC samples archived in Department of Pathology in the First Affiliated Hospital of Wenzhou Medical University were selected. The expression of vimentin and Ki-67 proteins in CSCC tissue were detected using immunohistochemical SP method, and correlations between them and their relationships with clinicopathological features were analyzed. Results: Among 57 CSCC tissues, there were 43 with positive expression of Vimentin, and the positive rate was 75.4%; there were 57 cases with positive expression of Ki-67, and the positive rate came up to 100.0%. The results of Pearson correlation analysis displayed that the expression of vimentin had a significantly-positive correlation with Ki-67 in CSCC tissue (r=0.984, co0.000). The expression of both Ki-67 and vimentin was intimately associated with the presence or absence of local invasion and lymph node metastasis as well as differentiated degrees of the tumor (P=0.003, 0.017, 0.000; P=0.001, 0.008, 0.003) instead of the age, tumor size and clinical staging (P>0.05). Conclusions: Epithelial-mesenchymal transition (EMT) tends to appear in poorly-differentiated CSCC tissue, and the up-regulation of vimentin expression is accompanied by high expression of Ki-67, suggesting that invasion and metastasis readily occur in these tumor cells.

Effect of CXCR4 and CD133 Co-expression on the Prognosis of Patients with Stage II~III Colon Cancer

  • Li, Xiao-Feng;Guo, Xiao-Guang;Yang, Yong-Yan;Liu, Ai-Yong
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권3호
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    • pp.1073-1076
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    • 2015
  • Background: To explore the relationship between CXCR4, CD133 co-expression and clinicopathological features as well as prognosis of patients with phase II~III colon cancer. Materials and Methods: Forty-nine paraffin-embedded samples of tumor tissue and epithelial tissue adjacent to cancer were collected from patients with colon cancer undergoing radical surgery in Baotou Cancer Hospital from January, 2010 to June, 2011. CXCR4 and CD133 expression was detected using immunohistochemistry and its relationship with clinicopathological features and the 3-year survival rate was analyzed. Results: In the tumor tissue and colonic epithelial tissue adjacent to cancer, the positive expression rates of CXCR4 were respectively 61.2% (30/49) and 8.16% (4/49), while those of CD133 being 36.7% (18/49) and 6.12% (3/49). CXCR4 and CD133 expression in tumor tissue was not related to patient age, gender, primary focal sites, tumor size, TNM staging, histological type, tumor infiltration depth and presence or absence of lymphatic metastasis, but CXCR4 and CD133 co-expression was associated with TNM staging and lymphatic metastasis. The 3-year survival rate of patients with CXCR4 and CD133 co-expression was 27.3% (3/11), and that of the remainderwas 76.3% (29/38), the difference being significant ($X^2=7.0206$, p=0.0081). Conclusions: CXCR4 and CD133 co-expression may be a risk factor for poor prognosis of patients with stage II~III colon cancer.

Impact of Co-transfection with Livin and Survivin shRNA Expression Vectors on Biological Behavior of HepG2 Cells

  • Xu, Wei;Chang, Hong;Qin, Cheng-Kun;Zhai, Yun-Peng
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권9호
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    • pp.5467-5472
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    • 2013
  • Objective: To construct short hairpin RNA (shRNA) eukaryotic expression vectors targeting Livin and Survivin genes, and to explore the impact of co-transfection of Livin and Survivin shRNA expression vectors on the biological behavior of HepG2 cells. Methods: shRNA eukaryotic expression vectors pSD11-Livin and pSD11-Survivin were designed and constructed then transfected into HepG2 cells separately or in combination. mRNA and protein expression in transfected cells was assessed by quantitative fluorescence PCR and Western blotting, respectively. Cell proliferation was measured by MTT assay and cell apoptosis by TUNEL assay. Results: The Livin and Survivin shRNA eukaryotic expression vectors were successfully constructed and transfected into HepG2 cells. The relative mRNA expression levels of Livin and Survivin in HepG2 cells co-transfected with pSD11-Livin and pSD11-Survivin were $0.12{\pm}0.02$ and $0.33{\pm}0.13$, respectively, which was significantly lower than levels in cells transfected with either pSD11-Livin or pSD11-Survivin (P<0.05). The relative protein expression levels of Livin and Survivin in the co-transfected cells were also significantly decreased compared to single-transfection (P<0.05). The inhibition rate of cell growth in the co-transfection group was higher than that in the single-transfection groups at 48 h, 60 h, or 72 h after transfection (P<0.01). The apoptotic rate increased to the greatest extent in the co-transfection group relative to any other group (P<0.05). Conclusions: Co-transfection with pSD11-Livin and pSD11-Survivin was more efficient than transfection with either vector alone in reducing the mRNA and protein expression of Livin and Survivin genes in HepG2 cells. Co-transfection also inhibited the proliferation of transfected cells more than the other groups, and induced cellular apoptosis more effectively.

Regulation of the expression of nhaA gene coding $Na^{+}$/$H^{+}$ antiporter A of escherichia coli

  • Seo, Sung-Yum;Lee, Seung-Heon
    • Journal of Microbiology
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    • 제33권2호
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    • pp.120-125
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    • 1995
  • .betha.-galactosidase activity of Escherichia coli cells containing operon fusion nhaA'-'lacZ was monitored to study the regulation of expression of nhaA gene under various conditions. The expression of the fusion was enhanced only by chemicals containing Na$^{+}$ or Li$^{+}$. This Na$^{+}$ or Li$^{+}$. This Na$^{+}$(Li$^{+}$)-specific enhancement of .betha.-galactosidase activity represented the increase in the rate of synthesis of .betha.-galactosidase rather than the decrease in the breakdown rate. The induction pattern was influenced by copy numbers of the gene. Induction by Na$^{+}$ or Li$^{+}$ was concentration and time dependent, reaching maximum 5-6 fold induction after 2 hours at 0.4-0.5 M for Na$^{+}$ or at 0.25-0.35 M for Li$^{+}$, Although the expression was induced at much lower concentration of Na$^{+}$ at alkaline pH values than at neutral pH in the presence of Na$^{+}$, alkaline pH itself did ot induced the expression of the fusion in the absence of Na$^{+}$. Temperature shift and growth phase of culture did not affect the level of induction.he level of induction.

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siRNA Interference with a Proliferation-Inducing Ligand Gene in the Sgr-7901 Gastric Carcinoma Cell Line

  • Ni, Shao-Zhong;Cao, Hong-Yong;Chen, Zheng;Zhu, Yi;Xu, Ze-Kuan
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권4호
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    • pp.1511-1514
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    • 2012
  • Objective: The present study aimed to investigate the influence of siRNA interference with a proliferation-inducing ligand (APRIL) gene on gastric carcinoma sgr-7901 cell apoptosis. Correlations between APRIL silencing and tyrosine kinase (trka) expression were also explored. Methods: Two APRIL-silencing siRNA vectors were constructed, and transfected into human gastric carcinoma sgr-7901 cells, expression before and after transfection being detected using RT-PCR and western blot analyses. The expression of 15 trka genes was detected using RT-PCR and apoptotic rates of sgr-7901 were assessed by flow cytometry. Results: The expression levels of receptor trka genes were significantly decreased, and the apoptotic rate of sgr-7901 was significantly increased after transfection (P < 0.05). Conclusion: APRIL gene silencing can increase the apoptotic rate of gastric carcinoma cells, and inhibit the expression of receptor trka genes. There is a correlation between the signaling pathways of APRIL and trka.

Mechanisms Underlying the Effects of LPS and Activation-induced Cytidine Deaminase on IgA Isotype Expression

  • Park, Seok-Rae;Kim, Hyun-A;Chun, Sung-Ki;Park, Jae-Bong;Kim, Pyeung-Hyeun
    • Molecules and Cells
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    • 제19권3호
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    • pp.445-451
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    • 2005
  • Activation-induced cytidine deaminase (AID) is needed for Ig class switch recombination (CSR). We explored the effect of LPS on the expression of AID during B cell differentiation, and the role of AID in IgA isotype expression. In normal spleen B cells, LPS increased AID transcription up to 48 h post-stimulation, i.e. around the time of Ig CSR. TGF-${\beta}1$ and AID were required for IgA expression, and LPS contributed to $TGF{\beta}1$-induced IgA production largely by inducing AID. Interestingly, LPS repressed AID transcription in $sIgA^+$ B cells but still stimulated IgA production mainly by increasing the rate of IgA secretion. Our data indicate that LPS contributes to $TGF{\beta}1$-induced IgA isotype expression in at least two ways: by stimulating AID transcription before CSR and by enhancing the IgA secretion rate after CSR.