• 제목/요약/키워드: Preclinical

검색결과 473건 처리시간 0.027초

FAP Inhibitors as Novel Small Molecules for Cancer Imaging using Radionuclide

  • Anvar Mirzaei;Jung-Joon Min;Dong-Yeon Kim
    • 대한방사성의약품학회지
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    • 제9권1호
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    • pp.49-55
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    • 2023
  • Tumors are encircled by various non-cancerous cell types in the extracellular matrix, including fibroblasts, endothelial cells, immune cells, and cytokines. Fibroblasts are the most critical cells in the tumor stroma and play an important role in tumor development, which has been highlighted in some epithelial cancers. Many studies have shown a tight connection between cancerous cells and fibroblasts in the last decade. Regulatory factors secreted into the tumor environment by special fibroblast cells, cancer-associated fibroblasts (CAFs), play an important role in tumor and vessel development, metastasis, and therapy resistance. This review addresses the development of FAP inhibitors, emphasizing the first, second, and latest generations. First-generation inhibitors exhibit low selectivity and chemical stability, encouraging researchers to develop new scaffolds based on preclinical and clinical data. Second-generation enzymes such as UAMC-1110 demonstrated enhanced FAP binding and better selectivity. Targeted treatment and diagnostic imaging have become possible by further developing radionuclide-labeled fibroblast activation protein inhibitors (FAPIs). Although all three FAPIs (01, 02, and 04) showed excellent preclinical and clinical findings. The final optimization of these FAPI scaffolds resulted in FAPI-46 with the highest tumor-to-background ratio and better binding affinity.

Preclinical study of a novel ingestible bleeding sensor for upper gastrointestinal bleeding

  • Kimberly F. Schuster;Christopher C. Thompson;Marvin Ryou
    • Clinical Endoscopy
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    • 제57권1호
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    • pp.73-81
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    • 2024
  • Background/Aims: Upper gastrointestinal bleeding (UGIB) is a life-threatening condition that necessitates early identification and intervention and is associated with substantial morbidity, mortality, and socioeconomic burden. However, several diagnostic challenges remain regarding risk stratification and the optimal timing of endoscopy. The PillSense System is a noninvasive device developed to detect blood in patients with UGIB in real time. This study aimed to assess the safety and performance characteristics of PillSense using a simulated bleeding model. Methods: A preclinical study was performed using an in vivo porcine model (14 animals). Fourteen PillSense capsules were endoscopically placed in the stomach and blood was injected into the stomach to simulate bleeding. The safety and sensitivity of blood detection and pill excretion were also investigated. Results: All the sensors successfully detected the presence or absence of blood. The minimum threshold was 9% blood concentration, with additional detection of increasing concentrations of up to 22.5% blood. All the sensors passed naturally through the gastrointestinal tract. Conclusions: This study demonstrated the ability of the PillSense System sensor to detect UGIB across a wide range of blood concentrations. This ingestible device detects UGIB in real time and has the potential to be an effective tool to supplement the current standard of care. These favorable results will be further investigated in future clinical studies.

체외수정시술 후 임신된 환자에서 혈중 ${\beta}-hCG$ 측정에 의한 임신 결과 예측에 관한 연구 (Predictive Value of Serum ${\beta}-hCG$ Level in Pregnancies following In vitro Fertilization and Embryo Transfer)

  • 김석현;서창석;최두석;최영민;신창재;김정구;문신용;이진용;장윤석
    • Clinical and Experimental Reproductive Medicine
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    • 제19권1호
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    • pp.41-48
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    • 1992
  • Serum level of ${\beta}$ subunit of human chorionic gonadotropin (${\beta}-hCG$) was studied to evaluate its predictability of pregnancy outcome in 98 in vitro fertilization and embryo transfer(IVF-ET) patients using gonadotropin-releasing hormone(GnRH) agonist. Serial serum ${\beta}-hCG$ levels were established for 42 singleton pregnancies, 20 normal multiple pregnancies, 18 preclinical abortions, 14 clinical abortions and 4 ectopic pregnancies. In comparison to normal singleton pregnancies, multiple pregnancies showed significantly higher ${\beta}-hCG$ levels on the post-ET day 10 to 13 and day 24 to 25. Clinical abortions did not show significantly lower ${\beta}-hCG$ levels in early pregnancy except the post-ET day 16-17, but showed significantly lower ${\beta}-hCG$ levels from the post-ET day 22, compared with singleton pregnancies. Preclinical abortions showed significantly lower ${\beta}-hCG$ levels than those of singleton pregnancies. Ectopic pregnancies showed lower ${\beta}-hCG$ levels than those of singleton pregnancies without statistical significance. In conclusion, determination of serum ${\beta}-hCG$ level in early pregnancy is a useful tool for the prediction of preclinical abortions and multiple pregnancies and serial measurement of serum ${\beta}-hCG$ levels will be helpful in predicting clinical abortion.

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The -765G>C Polymorphism in the Cyclooxygenase-2 Gene and Digestive System Cancer: a Meta-analysis

  • Zhao, Fen;Cao, Yue;Zhu, Hong;Huang, Min;Yi, Cheng;Huang, Ying
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권19호
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    • pp.8301-8310
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    • 2014
  • Background: Published data regarding associations between the -765G>C polymorphism in cyclooxygenase-2 (COX-2) gene and digestive system cancer risk have been inconclusive. The aim of this study was to comprehensively evaluate the genetic risk of the -765G>C polymorphism in the COX-2 gene for digestive system cancer. Materials and Methods: A search was performed in Pubmed, Medline (Ovid), Embase, CNKI, Weipu, Wanfang and CBM databases, covering all studies until Feb 10, 2014. Statistical analysis was performed using Revman5.2. Results: A total of 10,814 cases and 16,174 controls in 38 case-control studies were included in this meta-analysis. The results indicated that C allele carriers (GC+CC) had a 20% increased risk of digestive system cancer when compared with the homozygote GG (odds ratio (OR)=1.20, 95% confidence interval (CI), 1.00-1.44 for GC+CC vs GG). In the subgroup analysis by ethnicity, significant elevated risks were associated with C allele carriers (GC+CC) in Asians (OR = 1.46, 95% CI=1.07-2.01, and p=0.02) and Africans (OR=2.12, 95% CI=1.57-2.87, and p< 0.00001), but not among Caucasians, Americans and mixed groups. For subgroup analysis by cancer type (GC+CC vs GG), significant associations were found between the -765G>C polymorphism and higher risk for gastric cancer (OR=1.64, 95% CI=1.03-2.61, and p=0.04), but not for colorectal cancer, oral cancer, esophageal cancer, and others. Regarding study design (GC+CC vs GG), no significant associations were found in then population-based case-control (PCC), hospital-based case-control (HCC) and family-based case-control (FCC) studies. Conclusions: This meta-analysis suggested that the -765G>C polymorphism of the COX-2 gene is a potential risk factor for digestive system cancer in Asians and Africans and gastric cancer overall.

The 765G>C Polymorphism in the Cyclooxygenase-2 Gene and Gastric Cancer Risk: an Update by Meta-analysis

  • Zhao, Fen;Zhu, Hong;Huang, Min;Yi, Cheng;Huang, Ying
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권6호
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    • pp.2863-2868
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    • 2014
  • Background: The 765G>C polymorphism in cyclooxygenase-2 (COX-2) gene has been extensively investigated for association with gastric cancer (GC). However, the results of different studies have been inconsistent. The aim of this study is to comprehensively evaluate the genetic risk of -765G>C polymorphism in the COX-2 gene for GC. Materials and Methods: We searched Pubmed, Embase, Medline, CNKI database, Wanfang database, Weipu database, and Chinese Biomedical database, covering all publications (last search been performed on Jan 10, 2014). Statistical analyses were performed using Revman 5.2 and STATA 10.0 software. Results: A total of 1,874 cases and 3,005 controls in 10 case-control studies were included in this meta-analysis. The results indicated that the variant C allele carriers (GC+CC) had a 69% increased risk of GC when compared with the homozygote GG (odds ratio (OR)=1.69, 95% confidence interval (CI), 1.10-2.61 for GC+CC vs GG). In the subgroup analysis by ethnicity, significant elevated risks were associated with C allele carriers in Asians (OR=1.75, 95%CI=1.40-2.18, and p<0.00001) and in Indians (OR=8.38, 95%CI=4.34-16.16, and p<0.00001) but not in Caucasians (OR=1.07, 95%CI=0.81-1.42, and p=0.62) or in Dutch (OR=0.53, 95%CI= 0.33-0.87, and p= 0.01).In the subgroup analysis by Helicobacter pylori (H. pylori) status, a significantly increased risk was identified among H. pylori (+) (OR=3.58, 95%CI=2.33-3.50, and p<0.00001) and H. pylori (-) (OR=2.32, 95%CI=1.46-3.69, and p=0.0004). Conclusions: This meta-analysis suggested that the -765G>C polymorphism in the COX-2 gene could be a risk factor for GC in Asians and Indians.

Herpes simplex Virus Type-1 Thymidine Kinase 유전자의 크로닝 (Cloning of Thymidine Kinase Gene of Herpes simplex Virus Type-1)

  • 강현;박갑주;차성철;김수영;양기상;김남주;이형환
    • 대한바이러스학회지
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    • 제26권1호
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    • pp.121-129
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    • 1996
  • Herpes simplex virus type-1의 vero 세포에서의 증식기작을 규명하기 위해 전자현미경으로 관찰하였고, 유전학적 특성을 규명하기 위해 유전자도서관을 작성하였고, thymidine kinase (TK) 유전자를 클로닝을 하였다. 감염 48시간 후 많은 수의 바이러스 nucleocapsid가 핵뿐만 아니라 세포질에서 관찰되었다. 바이러스는 세포에 감염된 후 핵내에서 복제증식한 후 세포질내로 이동하였으며, 이때 핵막을 통과하면서 외투막을 갖고 세포질로 이동하여 세포밖으로 나가는 것을 관찰할 수 있었으며, 또한 일부 nucleocapsid는 세포막을 출아하여 비리온으로 출아되었다. HSV-1의 DNA를 BamHI과 BglII 제한효소로 각각 절단하여 DNA의 절단 양상을 조사하였다. BamHI에 의해 절단된 단편은 27개 이었고, 그들 분자량의 범위는 1.1 - 14 kb이었으며, BglII에 의해 절단된 단편은 16개이었고, 분자량의 범위는 4.5 - 20.1 kb이었다. Southern blot 방법으로 TK 유전자를 포함하고 있는 단편을 확인하였는데, pHLA-12와 pHLB-14클론에 포함되어 있었고 각 단편의 분자량은 3.74와 6.41 kb이었다.

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Establishment of a [18F]-FDG-PET/MRI Imaging Protocol for Gastric Cancer PDX as a Preclinical Research Tool

  • Bae, Seong-Woo;Berlth, Felix;Jeong, Kyoung-Yun;Suh, Yun-Suhk;Kong, Seong-Ho;Lee, Hyuk-Joon;Kim, Woo Ho;Chung, June-Key;Yang, Han-Kwang
    • Journal of Gastric Cancer
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    • 제20권1호
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    • pp.60-71
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    • 2020
  • Purpose: The utility of 18-fluordesoxyglucose positron emission tomography ([18F]-FDG-PET) combined with computer tomography or magnetic resonance imaging (MRI) in gastric cancer remains controversial and a rationale for patient selection is desired. This study aims to establish a preclinical patient-derived xenograft (PDX) based [18F]-FDG-PET/MRI protocol for gastric cancer and compare different PDX models regarding tumor growth and FDG uptake. Materials and Methods: Female BALB/c nu/nu mice were implanted orthotopically and subcutaneously with gastric cancer PDX. [18F]-FDG-PET/MRI scanning protocol evaluation included different tumor sizes, FDG doses, scanning intervals, and organ-specific uptake. FDG avidity of similar PDX cases were compared between ortho- and heterotopic tumor implantation methods. Microscopic and immunohistochemical investigations were performed to confirm tumor growth and correlate the glycolysis markers glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) with FDG uptake. Results: Organ-specific uptake analysis showed specific FDG avidity of the tumor tissue. Standard scanning protocol was determined to include 150 μCi FDG injection dose and scanning after one hour. Comparison of heterotopic and orthotopic implanted mice revealed a long growth interval for orthotopic models with a high uptake in similar PDX tissues. The H-score of GLUT1 and HK2 expression in tumor cells correlated with the measured maximal standardized uptake value values (GLUT1: Pearson r=0.743, P=0.009; HK2: Pearson r=0.605, P=0.049). Conclusions: This preclinical gastric cancer PDX based [18F]-FDG-PET/MRI protocol reveals tumor specific FDG uptake and shows correlation to glucose metabolic proteins. Our findings provide a PET/MRI PDX model that can be applicable for translational gastric cancer research.

Matrine Reduces Proliferation of Human Lung Cancer Cells by Inducing Apoptosis and Changing miRNA Expression Profiles

  • Liu, Yong-Qi;Li, Yi;Qin, Jie;Wang, Qian;She, Ya-Li;Luo, Ya-Li;He, Jian-Xin;Li, Jing-Ya;Xie, Xiao-Dong
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권5호
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    • pp.2169-2177
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    • 2014
  • Matrine, a main active component extracted from dry roots of Sophora flavecens, has been reported to exert antitumor effects on A549 human non-small lung cancer cells, but its mechanisms of action remain unclear. To determine effects of matrine on proliferation of A549 cells and assess possible mechanisms, MTT assays were employed to detect cytotoxicity, along with o flow cytometric analysis of DNA content of nuclei of cells following staining with propidium iodide to analyze cell cycle distribution. Western blotting was performed to determined expression levels of Bax, Bcl-2, VEGF and HDAC1, while a microarray was used to assessed changes of miRNA profiles. In the MTT assay, matrine suppressed growth of human lung cancer cell A549 in a dose- and timedependent manner at doses of 0.25-2.5 mg/ml for 24h, 48h or 72h. Matrine induced cell cycle arrest in G0/G1 phase and decreased the G2/M phase, while down-regulating the expression of Bcl2 protein, leading to a reduction in the Bcl-2/Bax ratio. In addition, matrine down regulated the expression level of VEGF and HDAC1 of A549 cells. Microarray analysis demonstrated that matrine altered the expression level of miRNAs compared with untreated control A549 cells. In conclusion, matrine could inhibit proliferation of A549 cells, providing useful information for understanding anticancer mechanisms.

유방암 조기진단을 위한 검진주기 결정에 대한 연구 (A Study on Scheduling Periodic Examinations for the Early Detection of Breast Cancer in Korea)

  • 정성화;강대룡;허남욱;김진흠;이순영;정상혁;남정모
    • Journal of Preventive Medicine and Public Health
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    • 제39권4호
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    • pp.346-352
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    • 2006
  • Objectives: The purposes of this study were to propose a screening schedule for the early detection of breast cancer among Korean women, as based on the statistical model, and to compare the efficacy of the proposed screening schedule with the current recommendations. Methods: The development of the screening schedule for breast cancer closely followed the work of Lee and Zelen (1998). We calculated the age-specific breast cancer incidence rate from the Korea Central Cancer Registry (2003), and then we estimated the scheduling of periodic examinations for the early detection of breast cancer, using mammography, and based on the threshold method. The efficacy of the derived screening schedule was evaluated by the schedule sensitivity. Results: For estimating the screening schedule threshold method, we set the threshold value as the probability of being in the preclinical stage at age 35, the sensitivity of mammography as 0.9 and the mean sojourn time in the preclinical stage as 4 years. This method generated 14 examinations within the age interval [40, 69] of 40.0, 41.3, 42.7, 44.1, 45.4, 46.7, 48.0, 49.3, 51.0, 53.2, 55.3, 57.1, 59.0 and 63.6 years, and the schedule sensitivity was 75.4%. The proposed screening schedule detected 85.2% (74.5/87.4) of the cases that could have been detected by annual screening, but it required only about 48.7% (14.0/30.0) of the total number of examinations. We also examined the threshold screening schedules for a range of sensitivities of mammography and the mean sojourn time in the preclinical stage. Conclusions: The proposed screening schedule for breast cancer with using the threshold method will be helpful to provide guidelines for a public health program for choosing an effective screening schedule for breast cancer among Korean women.

각 층의 서로 다른 크기의 섬광체를 사용한 반응 깊이 측정 검출기 설계 (DOI Detector Design using Different Sized Scintillators in Each Layer)

  • 이승재
    • 한국방사선학회논문지
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    • 제17권1호
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    • pp.11-16
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    • 2023
  • 전임상용 양전자방출단층촬영기기는 관심 시야 외곽에서의 공간분해능 저하현상이 발생한다. 이를 해결하기 위해 감마선과 섬광체가 상호작용한 위치를 측정하는 반응 깊이 측정(depth of interaction, DOI) 검출기가 개발되었다. 여러 층으로 섬광 픽셀 배열을 구성한 방법, 하나의 층의 양단에 광센서를 배치한 방법, 여러 층으로 섬광 픽셀 배열을 구성하고 각 층마다 광센서를 배치한 방법 등이 있다. 본 연구에서는 기존에 개발된 검출기들의 특징을 분석하여 새로운 형태의 DOI 검출기를 설계하였다. 두층으로 구성된 검출기는 각 층마다 서로 다른 크기의 섬광 픽셀을 사용하여, 배열의 크기를 다르게 구성하였다. 이러한 형태로 구성할 경우 층별 섬광 픽셀의 위치는 서로 어긋나게 배열되어 평면 영상에서 서로 다른 위치에 영상화된다. 설계한 검출기의 반응 깊이 측정 가능성을 확인하기위해 DETECT2000 시뮬레이션을 수행하였다. 각 섬광 픽셀의 중심에서 발생된 감마선 이벤트로 획득한 빛의 신호로 평면 영상을 재구성하였다. 그 결과 각 층별 모든 섬광 픽셀이 재구성된 평면 영상에서 분리되어 영상화되어, 반응 깊이를 측정할 수 있음을 확인할 수 있었다. 본 검출기를 전임상용 PET에 적용할 경우 공간분해능의 향상을 이루어 우수한 영상을 획득할 수 있을 것으로 사료된다.