1
|
Zhou H, Jia Q, Sun J, Li Y, He Y, Bi W, Zheng W. Improved Bending Strength and Thermal Conductivity of Diamond/Al Composites with Ti Coating Fabricated by Liquid-Solid Separation Method. Materials (Basel) 2024; 17:1485. [PMID: 38611999 PMCID: PMC11012702 DOI: 10.3390/ma17071485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 04/14/2024]
Abstract
In response to the rapid development of high-performance electronic devices, diamond/Al composites with high thermal conductivity (TC) have been considered as the latest generation of thermal management materials. This study involved the fabrication of diamond/Al composites reinforced with Ti-coated diamond particles using a liquid-solid separation (LSS) method. The interfacial characteristics of composites both without and with Ti coatings were evaluated using SEM, XRD, and EMPA. The results show that the LSS technology can fabricate diamond/Al composites without Al4C3, hence guaranteeing excellent mechanical and thermophysical properties. The higher TC of the diamond/Al composite with a Ti coating was attributed to the favorable metallurgical bonding interface compounds. Due to the non-wettability between diamond and Al, the TC of uncoated diamond particle-reinforced composites was only 149 W/m·K. The TC of Ti-coated composites increased by 85.9% to 277 W/m·K. A simultaneous comparison and analysis were performed on the features of composites reinforced by Ti and Cr coatings. The results suggest that the application of the Ti coating increases the bending strength of the composite, while the Cr coating enhances the TC of the composite. We calculate the theoretical TC of the diamond/Al composite by using the differential effective medium (DEM) and Maxwell prediction model and analyze the effect of Ti coating on the TC of the composite.
Collapse
Affiliation(s)
- Hongyu Zhou
- National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083, China;
| | - Qijin Jia
- Beijing System Design Institute of Electro-Mechanic Engineering, Beijing 100039, China;
| | - Jing Sun
- Beijing Hangxing Machinery Co., Ltd., Beijing 100013, China;
| | - Yaqiang Li
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China;
| | - Yinsheng He
- National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083, China;
| | - Wensi Bi
- National Academy of Forestry and Grassland Administration, Beijing 102600, China;
| | - Wenyue Zheng
- National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083, China;
| |
Collapse
|
2
|
Wang W, Wilson C, Collum S, Bi W, Ko J, Rajagopal K, Karmouty-Quintana H. Beta Adrenoceptor Ligands for the Treatment of Group 3 Pulmonary Hypertension and Cor Pulmonale: A Novel Therapeutic Target? J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
3
|
Wu F, Xing YZ, Bi W, Liu JX. [The value of lean nystagmus and sitting to supine positioning nystagmus in the diagnosis of horizontal semicircular canal benign paroxysmal positional vertigo]. Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2019; 33:106-109. [PMID: 30808132 DOI: 10.13201/j.issn.1001-1781.2019.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Indexed: 11/12/2022]
Abstract
Objective: To explore the value of 1ean nystagmus and sitting to supine positioning nystagmus in the diagnosis of horizontal semicircular canal benign paroxysmal positional vertigo. Method: One hundred cases of patients with definitive diagnosis of horizontal semicircular canal benign paroxysmal positional vertigo were tested by 1ean nystagmus and sitting to supine positioning nystagmus and supine roll test. The affected side was recorded according to the nystagmus direction. After diagnosis, they were treated with canalith repositioning procedure. The canalith repositioning procedure was made according to the supine roll test result when 1ean nystagmus and sitting to supine positioning nystagmuscannot be induced. Furthermore,the canalith repositioning procedure was made according to the1ean nystagmus and sitting to supine positioning nystagmuswhenthe supine roll test cannot diagnose. The patients with canalolithiasis were randomly divided into two groups when both 1ean nystagmus and sitting to supine positioning nystagmusand the supine roll test can be induced. One group was treated with canalith repositioning procedure based on results of supine roll test and the other group was treated based on the results of1ean nystagmus and sitting to supine positioning nystagmus. The detection rate and diagnostic coincidence rate of 1ean nystagmus and sitting to supine positioning nystagmus were calculated and the shortterm outcome were evaluated one day after treatment. Result: The detection rate of 1ean nystagmus and sitting to supine positioning nystagmus was 83% and the coincidence rate with the roll test was 90.1%,respectively. There was no significant statistical difference between the treatment effect according to lean nystagmus and sitting to supine positioning nystagmus and supine roll test. Conclusion: Lean nystagmus and sitting to supine positioning nystagmus cannot be used alone in the diagnosis ofhorizontal semicircular canal benign paroxysmal positional vertigo. They need to be combined with supine roll test. However, when the supine roll test is difficult to demonstrate the affected side, it can be used as an auxiliary diagnostic method. When the results of 1ean nystagmus and sitting to supine positioning nystagmusand the supine roll test are inconsistent, repeat the test and conduct a comprehensive assessment to avoid missed diagnosis and misdiagnosis..
Collapse
Affiliation(s)
- F Wu
- Department of Otorhinolaryngology, Tianjin Union Medical Center, Tianjin, 300121, China
| | - Y Z Xing
- Department of Otorhinolaryngology, Tianjin Union Medical Center, Tianjin, 300121, China
| | - W Bi
- Department of Otorhinolaryngology, Tianjin Union Medical Center, Tianjin, 300121, China
| | - J X Liu
- Department of Otorhinolaryngology, Tianjin Union Medical Center, Tianjin, 300121, China
| |
Collapse
|
4
|
Song J, Fabbris G, Bi W, Haskel D, Schilling JS. Pressure-Induced Superconductivity in Elemental Ytterbium Metal. Phys Rev Lett 2018; 121:037004. [PMID: 30085803 DOI: 10.1103/physrevlett.121.037004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/30/2018] [Indexed: 06/08/2023]
Abstract
Ytterbium (Yb) metal is divalent and nonmagnetic (4f^{14} configuration). Under pressure its valence increases significantly leading to the expectation that magnetic instabilities and other highly correlated electron effects may appear before a stable trivalent state is reached (4f^{13} configuration). We carried out electrical resistivity and ac magnetic susceptibility measurements to 179 GPa over the temperature range 1.4-295 K. No evidence for magnetic order is observed. However, Yb becomes a superconductor at 86 GPa with T_{c}≃1.4 K, increasing to 4.6 K at 179 GPa. X-ray absorption spectroscopy shows that Yb remains mixed valent to at least 125 GPa, pointing to an active role of f electrons in the emergence of superconductivity in this simple, elemental solid.
Collapse
Affiliation(s)
- J Song
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - G Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - W Bi
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Department of Geology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - D Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J S Schilling
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| |
Collapse
|
5
|
Suleiman J, Al Hashem AM, Tabarki B, Al-Thihli K, Bi W, El-Hattab AW. PPP1R21 homozygous null variants associated with developmental delay, muscle weakness, distinctive facial features, and brain abnormalities. Clin Genet 2018; 94:351-355. [PMID: 29808498 DOI: 10.1111/cge.13387] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 01/19/2023]
Abstract
We present 3 children with homozygous null variants in the PPP1R21 gene. A 3-year-old girl had profound developmental delay, hypotonia and weakness, poor feeding, recurrent chest infections and respiratory failure, rotatory nystagmus, absent reflexes, and a homozygous nonsense variant c.2089C>T (p.Arg697*). A 2-year-old boy had profound developmental delay, weakness and hypotonia, recurrent chest infections and respiratory distress, undescended testes, rotatory nystagmus, hyporeflexia, and a homozygous nonsense variant c.427C>T (p.Arg143*). An 11-year-old girl with profound developmental delay, weakness and hypotonia, stereotypic movements, growth failure, hyporeflexia, and a homozygous frameshift variant c.87_88delAG (p.Gly30Cysfs*4). In addition, these children shared common facial features (thick eyebrows, hypertelorism, broad nasal bridge, short nose with upturned nasal tip and broad low-hanging columella, thick lips, low-set ears, and coarse facies with excessive facial hair), and brain abnormalities (cerebellar vermis hypoplasia, ventricular dilatation, and reduced white matter volume). Although PPP1R21 has not yet been linked to human disease, the consistency in the phenotype of individuals from unrelated families, the nature of the variants which result in truncated proteins, and the expected vital role for PPP1R21 in cellular function, all support that PPP1R21 is a novel disease-associated gene responsible for the phenotype observed in these individuals.
Collapse
Affiliation(s)
- J Suleiman
- Division of Neurology, Pediatrics Department, Tawam Hospital, Al Ain, United Arab Emirates.,Department of Pediatrics, College of Medicine and Health sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - A M Al Hashem
- Division of Genetics, Pediatrics Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - B Tabarki
- Division of Neurology, Pediatrics Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - K Al-Thihli
- Genetic and Developmental Medicine Clinic, Sultan Qaboos University Hospital, Muscat, Oman
| | - W Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Baylor Genetics, Houston, Texas
| | - A W El-Hattab
- Division of Genetic and Metabolic Disorders, Pediatrics Department, Tawam Hospital, Al Ain, United Arab Emirates
| |
Collapse
|
6
|
Zhao JY, Bi W, Sinogeikin S, Hu MY, Alp EE, Wang XC, Jin CQ, Lin JF. A compact membrane-driven diamond anvil cell and cryostat system for nuclear resonant scattering at high pressure and low temperature. Rev Sci Instrum 2017; 88:125109. [PMID: 29289218 DOI: 10.1063/1.4999787] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A new miniature panoramic diamond anvil cell (mini-pDAC) as well as a unique gas membrane-driven mechanism is developed and implemented to measure electronic, magnetic, vibrational, and thermodynamic properties of materials using the nuclear resonant inelastic X-ray scattering (NRIXS) and the synchrotron Mössbauer spectroscopy (SMS) simultaneously at high pressure (over Mbar) and low temperature (T < 10 K). The gas membrane system allows in situ pressure tuning of the mini-pDAC at low temperature. The mini-pDAC fits into a specially designed compact liquid helium flow cryostat system to achieve low temperatures, where liquid helium flows through the holder of the mini-pDAC to cool the sample more efficiently. The system has achieved sample temperatures as low as 9 K. Using the membrane, sample pressures of up to 1.4 Mbar have been generated from this mini-pDAC. The instrument has been routinely used at 3-ID, Advanced Photon Source, for NRIXS and SMS studies. The same instrument can easily be used for other X-ray techniques, such as X-ray radial diffraction, X-ray Raman scattering, X-ray emission spectroscopy, and X-ray inelastic scattering under high pressure and low temperature. In this paper, technical details of the mini-pDAC, membrane engaging mechanism, and the cryostat system are described, and some experimental results are discussed.
Collapse
Affiliation(s)
- J Y Zhao
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave., Argonne, Illinois 60439, USA
| | - W Bi
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave., Argonne, Illinois 60439, USA
| | - S Sinogeikin
- High Pressure Collaborative Access Team, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA
| | - M Y Hu
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave., Argonne, Illinois 60439, USA
| | - E E Alp
- Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave., Argonne, Illinois 60439, USA
| | - X C Wang
- Institute of Physics, Chinese Academy of Sciences, Beijing 10090, People's Republic of China
| | - C Q Jin
- Institute of Physics, Chinese Academy of Sciences, Beijing 10090, People's Republic of China
| | - J F Lin
- Department of Geology Sciences, The University of Texas at Austin, Austin, Texas 78712, USA
| |
Collapse
|
7
|
Gao Y, Yang Y, Yuan F, Huang J, Xu W, Mao B, Yuan Z, Bi W. TNFα-YAP/p65-HK2 axis mediates breast cancer cell migration. Oncogenesis 2017; 6:e383. [PMID: 28945218 PMCID: PMC5623908 DOI: 10.1038/oncsis.2017.83] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 07/30/2017] [Accepted: 08/19/2017] [Indexed: 12/16/2022] Open
Abstract
Clinical and experimental evidence indicates that macrophages could promote solid-tumor progression and metastasis. However, the mechanisms underlying this process remain unclear. Here we show that yes-associated protein 1 (YAP1), a transcriptional regulator that controls tissue growth and regeneration, has an important role in tumor necrosis factor α (TNF α)-induced breast cancer migration. Mechanistically, macrophage conditioned medium (CM) or TNFα triggers IκB kinases (IKKs)-mediated YAP phosphorylation and activation in breast cancer cells. We further found that TNFα or macrophage CM treatment increases the interaction between p65 and YAP. Chromatin immunoprecipitation (ChIP) assay shows that YAP/TEAD (TEA domain family member) and p65 proteins synergistically regulate the transcription of hexokinase 2 (HK2), a speed-limiting enzyme in glycolysis, and promotes TNFα-induced or macrophage CM-induced cell migration. Together, our findings indicate an important role of TNFα-IKK-YAP/p65-HK2 signaling axis in the process of inflammation-driven migration in breast cancer cells, which reveals a new molecular link between inflammation and breast cancer metastasis.
Collapse
Affiliation(s)
- Y Gao
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Y Yang
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - F Yuan
- Department of Oncology, Chinese PLA General Hospital, Beijing, China
| | - J Huang
- Department of Orthopedics, Clinical Division of Surgery, Chinese PLA General Hospital, Beijing, China
| | - W Xu
- General Surgery Center, Chinese PLA General Hospital, Beijing, China
| | - B Mao
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Z Yuan
- The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, China
| | - W Bi
- Department of Orthopedics, Clinical Division of Surgery, Chinese PLA General Hospital, Beijing, China
| |
Collapse
|
8
|
Li T, Liu JX, Bi W, Xing YZ, Wu F. [Affected side location and clinical value of horizontal semicircular canal benign paroxysmal positional vertigo]. Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2017; 31:612-615. [PMID: 29871326 DOI: 10.13201/j.issn.1001-1781.2017.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Indexed: 11/12/2022]
Abstract
Objective:To explore the clinical value of rolling test(HRT), bow and lean test(BLT) and subjective vertigo sensation(SVS) for affected side localization of patients with horizontal semicircular canal benign paroxysmal positional vertigo(HSC-BPPV).Method:One hundred and thirty-eight patients(94 HSC-Can and 44 HSC-Cup)with HSC-BPPV were enrolled. Patients were tested with HRT and then were asked about SVS, followed by BLT. According to the results of HRT, SVS and BLT, HSC-Can and HSC-Cup were repositioned by Barbecue method and modified Kim method respectively. The detection rate of the affected side of HRT, BLT, SVS and the curative effect were analyzed. Result:In 94 HSC-Can patients and 44 HSC-Cup patients,BN and / or LN were induced by BLT to be 81.91% and 84.09% respectively. HRT induced bilateral asymmetric nystagmus 90.43%, 88.64%, SVS told vertigo symptoms worse side 60.64%,63.64%. There was no significant difference in the detection rate of HRT and BLT(P>0.05),but have significant difference with SVS(P<0.05). Excluding four patients in whom the comparison among HRT,BLT,SVS were inconclusive,we compared the curative effect of first treatment in 92 HSC-Can patients and 42 HSC-Cup patients. The curative effect of HRT positive only were 66.67% and 60.00% respectively , BLT positive only were 71.43% and 66.67% respectively , HRT and BLT both positive with ipsilateral affected side were 70.37% and 65.50% respectively , HRT and BLT both positive with contralateral affected side were 37.50% and 30.00% respectively. The curative effect of HRT positive only and BLT positive only had no significant difference with that of HRT and BLT both positive with ipsilateral affected side , but they both had significant difference with that of HRT and BLT both positive with contralateral affected side . Conclusion:HRT is the most effective method for detecting affected side of HSC-BPPV, but BLT and SVS also have auxiliary diagnostic value as HSC-BPPV localization method.
Collapse
Affiliation(s)
- T Li
- Graduate School of Tianjin Medical University, Tianjin, 300070,China
| | - J X Liu
- Department of Otolaryngology Head and Neck Surgery,Tianjin People's Hospital
| | - W Bi
- Department of Otolaryngology Head and Neck Surgery,Tianjin People's Hospital
| | - Y Z Xing
- Department of Otolaryngology Head and Neck Surgery,Tianjin People's Hospital
| | - F Wu
- Department of Otolaryngology Head and Neck Surgery,Tianjin People's Hospital
| |
Collapse
|
9
|
Xie DY, Liu ZX, Li YQ, Song J, Qiang W, Bi W, Wang DX. [Effect of moluodan on gastric secretion in atrophic gastritis rats]. Zhonghua Yi Xue Za Zhi 2016; 96:2729-2733. [PMID: 27667107 DOI: 10.3760/cma.j.issn.0376-2491.2016.34.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the effect of moluodan on gastric secretion and the underlying mechanism of moluodan in treating atrophic gastritis. Method: According to the random number table, 120 healthy male specific-pathogen-free (SPF) Sprague-Dawley rats were divided into 4 groups: control group, model group, moluodan low-dose group, and moluodan high-dose group, with 30 rats in each group. The control group was administered with normal saline 2 ml/d by gavage, the other three groups were administered with 2% sodium salicylate 1 ml/d, 20 mol/L sodium deoxycholate 1 ml/d, and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) 200 mg/kg for every 10 days. And 16 weeks later, the control group and model group were treated with normal saline 2 ml/d by gavage, meanwhile the moluodan low-dose group was treated with moluodan 0.9 g·kg-1·d-1and the high-dose group was treated with moluodan 1.8 g·kg-1·d-1, continuously for 12 weeks. Ten rats of each group were sacrificed at the end of 4, 8, 12 weeks. The effect of moluodan on atrophic gastritis was observed. The secretion function of gastric mucosa was assessed through detecting the numbers of gastrin-secreting cells (G cells) and somatostatin-secreting cell (D cells) in gastric mucosa using immunochemical staining, and measuring the serum levels of gastrin (GAS) and somatostatin (SS) using enzyme-linked immunosorbent assay (ELISA). Results: After 8 weeks, the numbers of G and D cells in gastric mucosa in the moluodan high-dose group significantly increased compared with the model group[(0.617±0.114) vs (0.476±0.116) cells/mm2, (0.504±0.084) vs (0.369±0.148) cells/mm2, both P<0.05]; the numbers of G and D cells in gastric mucosa in the low-dose group increased after 12-week's treatment[(0.674±0.129) vs (0.528±0.103) cells/mm2, (0.526±0.087) vs (0.371±0.058) cells/mm2, both P<0.05]. The serum GAS levels increased markedly after 8 weeks in the moluodan high-dose group and after 12 weeks in the low-dose group[(1.313±0.080) ng/ml vs (0.964±0.080) ng/ml, (1.202±0.124) ng/ml vs (0.909±0.054) ng/ml, both P<0.01]; the serum SS levels in both high- and low-dose groups were significantly lower than in the model group after 8-week's treatment[(2.376±0.199) ng/ml, (2.238±0.155) ng/ml vs (2.605±0.183) ng/ml, both P<0.05]. Conclusion: Moluodan may treat atrophic gastritis by repairing G and D cells in gastric mucosa and thus increasing serum levels of GAS.
Collapse
Affiliation(s)
- D Y Xie
- Department of Gastroenterology, Beijing Chaoyang Hospital, Beijing 100020, China
| | | | | | | | | | | | | |
Collapse
|
10
|
Coroller T, Bi W, Abedalthagafi M, Aizer A, Wu W, Greenwald N, Beroukhim R, Al-Mefty O, Santagata S, Dunn I, Alexander B, Huang R, Aerts H. SU-D-207B-02: Early Grade Classification in Meningioma Patients Combining Radiomics and Semantics Data. Med Phys 2016. [DOI: 10.1118/1.4955670] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
11
|
Patel A, Rosenfeld-Mokry J, Gambin T, Liu P, Bi W, Breman A, Smith J, Lalani S, Bacino C, Beaudet A, Lupski J, Shaw C, Cheung S, Stankiewicz P. Exon-Targeted Array CGH for Identification of Clinically Relevant Small-Sized, Intragenic CNVs. Cancer Genet 2016. [DOI: 10.1016/j.cancergen.2016.05.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
12
|
Liu H, Tse JS, Hu MY, Bi W, Zhao J, Alp EE, Pasternak M, Taylor RD, Lashley JC. Mechanisms for pressure-induced crystal-crystal transition, amorphization, and devitrification of SnI4. J Chem Phys 2015; 143:164508. [DOI: 10.1063/1.4934502] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- H. Liu
- Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B2, Canada
| | - J. S. Tse
- Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B2, Canada
| | - M. Y. Hu
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA
| | - W. Bi
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA
| | - J. Zhao
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA
| | - E. E. Alp
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA
| | - M. Pasternak
- School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Israel
| | - R. D. Taylor
- Los Alamos National Laboratory, PO Box 1663 Bikini Atoll Road, Los Alamos, New Mexico 87545, USA
| | - J. C. Lashley
- Los Alamos National Laboratory, PO Box 1663 Bikini Atoll Road, Los Alamos, New Mexico 87545, USA
| |
Collapse
|
13
|
Liu Z, Bi W, Li J, Li Q, Dong C, Zhao P, Lv H, Wang Z. Superior semicircular canal dehiscence in relation to the superior petrosal sinus: a potential cause of pulsatile tinnitus. Clin Radiol 2015; 70:943-7. [PMID: 26072165 DOI: 10.1016/j.crad.2015.04.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 04/08/2015] [Accepted: 04/28/2015] [Indexed: 02/07/2023]
Abstract
AIM To examine the association between superior semicircular canal dehiscence (SSCD) and pulsatile tinnitus (PT). MATERIALS AND METHODS Two SSCD groups included 408 unilateral persistent PT patients, and 511 controls undergoing head and neck dual-phase contrast-enhanced computed tomography (DP-CECT) for reasons other than PT. The prevalence of type I (no the superior petrosal sinus running through the dehiscence) and type II (superior semicircular canal dehiscence in relation to the superior petrosal sinus) SSCD was analysed using chi-square test. RESULTS SSCD was identified in 5.1% (21/408) of PT ears, significantly different from 2% (8/408) of non-PT ears and 0.7% (7/1022) of controls. There was no significant difference in SSCD prevalence between non-PT ears in the PT group and controls. In the PT group, 15/21 ears were type II SSCD; 6/21 ears were type I. Fifteen combined non-PT and control ears with SSCD included two type II and 13 type I SSCD. The prevalence of type II SSCD in PT ears was significantly higher than that of non-PT ears in both groups, and the prevalence of type I SSCD in PT ears was similar to that of non-PT ears in both groups. CONCLUSION Compared with type I SSCD, there may be a causal relationship between type II SSCD and PT.
Collapse
Affiliation(s)
- Z Liu
- Capital Medical University, Beijing Tongren Hospital, No. 1 Dong Jiao Min Street, Dongcheng District, Beijing, 100730, China.
| | - W Bi
- Shandong Medical Imaging Research Institute, No. 324 Jing 5 Road, Jinan, 250021, China
| | - J Li
- Capital Medical University, Beijing Tongren Hospital, No. 1 Dong Jiao Min Street, Dongcheng District, Beijing, 100730, China
| | - Q Li
- Capital Medical University, Beijing Tongren Hospital, No. 1 Dong Jiao Min Street, Dongcheng District, Beijing, 100730, China
| | - C Dong
- Capital Medical University, Beijing Friendship Hospital, No. 95 Yongan Road, Xicheng District, Beijing, 100050, China
| | - P Zhao
- Capital Medical University, Beijing Friendship Hospital, No. 95 Yongan Road, Xicheng District, Beijing, 100050, China
| | - H Lv
- Capital Medical University, Beijing Friendship Hospital, No. 95 Yongan Road, Xicheng District, Beijing, 100050, China
| | - Z Wang
- Capital Medical University, Beijing Friendship Hospital, No. 95 Yongan Road, Xicheng District, Beijing, 100050, China.
| |
Collapse
|
14
|
Probst FJ, James RA, Burrage LC, Rosenfeld JA, Bohan TP, Ward Melver CH, Magoulas P, Austin E, Franklin AIA, Azamian M, Xia F, Patel A, Bi W, Bacino C, Belmont JW, Ware SM, Shaw C, Cheung SW, Lalani SR. De novo deletions and duplications of 17q25.3 cause susceptibility to cardiovascular malformations. Orphanet J Rare Dis 2015; 10:75. [PMID: 26070612 PMCID: PMC4472615 DOI: 10.1186/s13023-015-0291-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 06/02/2015] [Indexed: 01/28/2023] Open
Abstract
Background Genomic disorders resulting from deletion or duplication of genomic segments are known to be an important cause of cardiovascular malformations (CVMs). In our previous study, we identified a unique individual with a de novo 17q25.3 deletion from a study of 714 individuals with CVM. Methods To understand the contribution of this locus to cardiac malformations, we reviewed the data on 60,000 samples submitted for array comparative genomic hybridization (CGH) studies to Medical Genetics Laboratories at Baylor College of Medicine, and ascertained seven individuals with segmental aneusomy of 17q25. We validated our findings by studying another individual with a de novo submicroscopic deletion of this region from Cytogenetics Laboratory at Cincinnati Children’s Hospital. Using bioinformatic analyses including protein-protein interaction network, human tissue expression patterns, haploinsufficiency scores, and other annotation systems, including a training set of 251 genes known to be linked to human cardiac disease, we constructed a pathogenicity score for cardiac phenotype for each of the 57 genes within the terminal 2.0 Mb of 17q25.3. Results We found relatively high penetrance of cardiovascular defects (~60 %) with five deletions and three duplications, observed in eight unrelated individuals. Distinct cardiac phenotypes were present in four of these subjects with non-recurrent de novo deletions (range 0.08 Mb–1.4 Mb) in the subtelomeric region of 17q25.3. These included coarctation of the aorta (CoA), total anomalous pulmonary venous return (TAPVR), ventricular septal defect (VSD) and atrial septal defect (ASD). Amongst the three individuals with variable size duplications of this region, one had patent ductus arteriosus (PDA) at 8 months of age. Conclusion The distinct cardiac lesions observed in the affected patients and the bioinformatics analyses suggest that multiple genes may be plausible drivers of the cardiac phenotype within this gene-rich critical interval of 17q25.3. Electronic supplementary material The online version of this article (doi:10.1186/s13023-015-0291-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- F J Probst
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - R A James
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - L C Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - J A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - T P Bohan
- Department of Neurology, Memorial Hermann Texas Medical Center, Houston, TX, USA
| | - C H Ward Melver
- Genetic Center, Children's Hospital Medical Center Of Akron, Akron, OH, USA
| | - P Magoulas
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - E Austin
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - A I A Franklin
- Department of Developmental Pediatrics, Texas Children's Hospital, Houston, TX, USA
| | - M Azamian
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - F Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - A Patel
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - W Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - C Bacino
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - J W Belmont
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - S M Ware
- Departments of Pediatrics and Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - C Shaw
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - S W Cheung
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - S R Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA.
| |
Collapse
|
15
|
|
16
|
Jindahra P, Bi W, Petrie A, Barbur JL, Plant GT. THE PUPIL LIGHT REFEX IN ACQUIRED HOMONYMOUS HEMIANOPIA. J Neurol Neurosurg Psychiatry 2012. [DOI: 10.1136/jnnp-2012-304200a.98] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
17
|
Gong Y, Bi W, Cao L, Yang Y, Chen J, Yu Y. Association of CD14-260 polymorphisms, red-complex periodontopathogens and gingival crevicular fluid cytokine levels with cyclosporine A-induced gingival overgrowth in renal transplant patients. J Periodontal Res 2012; 48:203-12. [PMID: 22934794 DOI: 10.1111/j.1600-0765.2012.01521.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2012] [Indexed: 12/13/2022]
Abstract
UNLABELLED BACKGROUD AND OBJECTIVE: Genetic factors may influence the colonization of pathogenic bacteria, therefore increasing the risk for the initiation and development of periodontal disease. The present study was carried out to investigate the association of CD14-260 polymorphisms, subgingival microbiota, and gingival crevicular fluid (GCF) cytokine levels with cyclosporine A (CsA)-induced gingival overgrowth (GO) in renal transplant patients. MATERIAL AND METHODS A total of 204 patients were dichotomized into two groups: 124 with GO and 80 without GO. The CD14-260 polymorphisms were measured using an allele-specific PCR method. The levels of periodontal pathogens were determined by real-time PCR of subgingival samples. GCF levels of IL-1β and sCD14 were detected by ELISA. RESULTS The frequency of CD14-260 genotype CT + TT was found to be similar in both groups. Patients with GO presented increased prevalence of Pg, Td, and Tf (red complex) and significantly higher levels of interleukin -1β than those without GO. Patients with GO carrying CT + TT genotypes were found to have higher frequencies of Pg, Td, and Tf than those carrying the CC genotype. Furthermore, in the presence of red complex, CT + TT genotypes were associated with higher interleukin -1β levels and severe GO. Multiple logistic regression analysis demonstrated that the severity of GO is not dependent on age, gender and pharmacological variables, being only associated with CD14-260 genotype and red complex periodontopathogens. CONCLUSION No association between CD14-260 polymorphisms and the prevalence of GO was revealed in renal transplant patients administered CsA. However, CD14-260 CT + TT genotypes are associated with the prevalence of red complex periodontopathogens in patients with GO, and may thus play some role in the development of severe CsA-induced GO.
Collapse
Affiliation(s)
- Y Gong
- Department of Stomatology, Zhongshan Hospital, Fudan University, Shanghai, China
| | | | | | | | | | | |
Collapse
|
18
|
Li N, Liu C, Bi W, Lin X, Jiao H, Zhao P. MRCP and 3D LAVA imaging of extrahepatic cholangiocarcinoma at 3 T MRI. Clin Radiol 2011; 67:579-86. [PMID: 22137873 DOI: 10.1016/j.crad.2011.10.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 10/20/2011] [Accepted: 10/26/2011] [Indexed: 12/19/2022]
Abstract
Extrahepatic cholangiocarcinoma (CCA) is a primary bile duct malignant tumour with poor prognosis. Familiarity with their varied imaging characteristics can be helpful in developing a correct diagnosis and in optimal treatment planning, and thus contribute to a better prognosis. The purpose of this article is to illustrate the typical appearances of extrahepatic CCA on magnetic resonance cholangiopancreatography (MRCP) and three-dimensional (3D) LAVA (liver acquisition with volume acceleration) sequences at 3 T magnetic resonance imaging (MRI), and to discuss the superiority of the two techniques in the diagnosis of CCA.
Collapse
Affiliation(s)
- N Li
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, People's Republic of China
| | | | | | | | | | | |
Collapse
|
19
|
Nagamani SCS, Zhang F, Shchelochkov OA, Bi W, Ou Z, Scaglia F, Probst FJ, Shinawi M, Eng C, Hunter JV, Sparagana S, Lagoe E, Fong CT, Pearson M, Doco-Fenzy M, Landais E, Mozelle M, Chinault AC, Patel A, Bacino CA, Sahoo T, Kang SH, Cheung SW, Lupski JR, Stankiewicz P. Microdeletions including YWHAE in the Miller-Dieker syndrome region on chromosome 17p13.3 result in facial dysmorphisms, growth restriction, and cognitive impairment. J Med Genet 2009; 46:825-33. [PMID: 19584063 DOI: 10.1136/jmg.2009.067637] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Deletions in the 17p13.3 region are associated with abnormal neuronal migration. Point mutations or deletion copy number variants of the PAFAH1B1 gene in this genomic region cause lissencephaly, whereas extended deletions involving both PAFAH1B1 and YWHAE result in Miller-Dieker syndrome characterised by facial dysmorphisms and a more severe grade of lissencephaly. The phenotypic consequences of YWHAE deletion without deletion of PAFAH1B1 have not been studied systematically. METHODS We performed a detailed clinical and molecular characterization of five patients with deletions involving YWHAE but not PAFAH1B1, two with deletion including PAFAH1B1 but not YWHAE, and one with deletion of YWHAE and mosaic for deletion of PAFAH1B1. RESULTS Three deletions were terminal whereas five were interstitial. Patients with deletions including YWHAE but not PAFAH1B1 presented with significant growth restriction, cognitive impairment, shared craniofacial features, and variable structural abnormalities of the brain. Growth restriction was not observed in one patient with deletion of YWHAE and TUSC5, implying that other genes in the region may have a role in regulation of growth with CRK being the most likely candidate. Using array based comparative genomic hybridisation and long range polymerase chain reaction, we have delineated the breakpoints of these nonrecurrent deletions and show that the interstitial genomic rearrangements are likely generated by diverse mechanisms, including the recently described Fork Stalling and Template Switching (FoSTeS)/Microhomology Mediated Break Induced Replication (MMBIR). CONCLUSIONS Microdeletions of chromosome 17p13.3 involving YWHAE present with growth restriction, craniofacial dysmorphisms, structural abnormalities of brain and cognitive impairment. The interstitial deletions are mediated by diverse molecular mechanisms.
Collapse
Affiliation(s)
- S C Sreenath Nagamani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Lalani SR, Thakuria JV, Cox GF, Wang X, Bi W, Bray MS, Shaw C, Cheung SW, Chinault AC, Boggs BA, Ou Z, Brundage EK, Lupski JR, Gentile J, Waisbren S, Pursley A, Ma L, Khajavi M, Zapata G, Friedman R, Kim JJ, Towbin JA, Stankiewicz P, Schnittger S, Hansmann I, Ai T, Sood S, Wehrens XH, Martin JF, Belmont JW, Potocki L. 20p12.3 microdeletion predisposes to Wolff-Parkinson-White syndrome with variable neurocognitive deficits. J Med Genet 2008; 46:168-75. [PMID: 18812404 DOI: 10.1136/jmg.2008.061002] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Wolff-Parkinson-White syndrome (WPW) is a bypass re-entrant tachycardia that results from an abnormal connection between the atria and ventricles. Mutations in PRKAG2 have been described in patients with familial WPW syndrome and hypertrophic cardiomyopathy. Based on the role of bone morphogenetic protein (BMP) signalling in the development of annulus fibrosus in mice, it has been proposed that BMP signalling through the type 1a receptor and other downstream components may play a role in pre-excitation. METHODS AND RESULTS Using the array comparative genomic hybridisation (CGH), we identified five individuals with non-recurrent deletions of 20p12.3. Four of these individuals had WPW syndrome with variable dysmorphisms and neurocognitive delay. With the exception of one maternally inherited deletion, all occurred de novo, and the smallest of these harboured a single gene, BMP2. In two individuals with additional features of Alagille syndrome, deletion of both JAG1 and BMP2 were identified. Deletion of this region has not been described as a copy number variant in the Database of Genomic Variants and has not been identified in 13 321 individuals from other cohort examined by array CGH in our laboratory. CONCLUSIONS Our findings demonstrate a novel genomic disorder characterised by deletion of BMP2 with variable cognitive deficits and dysmorphic features and show that individuals bearing microdeletions in 20p12.3 often present with WPW syndrome.
Collapse
Affiliation(s)
- S R Lalani
- Department of Molecular and Human Genetics, One Baylor Plaza, BCM225, MARB, R713, Houston, Texas 77030, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Lu X, Bi W, McNamee R, Weissfeld L, Klunk W, Mathis C, DeKosky S, Price J. Sources of variability in the PIB PET tissue time–activity data. Neuroimage 2008. [DOI: 10.1016/j.neuroimage.2008.04.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
22
|
Vissers LELM, Stankiewicz P, Yatsenko SA, Crawford E, Creswick H, Proud VK, de Vries BBA, Pfundt R, Marcelis CLM, Zackowski J, Bi W, van Kessel AG, Lupski JR, Veltman JA. Complex chromosome 17p rearrangements associated with low-copy repeats in two patients with congenital anomalies. Hum Genet 2007; 121:697-709. [PMID: 17457615 PMCID: PMC1914245 DOI: 10.1007/s00439-007-0359-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Accepted: 03/19/2007] [Indexed: 01/01/2023]
Abstract
Recent molecular cytogenetic data have shown that the constitution of complex chromosome rearrangements (CCRs) may be more complicated than previously thought. The complicated nature of these rearrangements challenges the accurate delineation of the chromosomal breakpoints and mechanisms involved. Here, we report a molecular cytogenetic analysis of two patients with congenital anomalies and unbalanced de novo CCRs involving chromosome 17p using high-resolution array-based comparative genomic hybridization (array CGH) and fluorescent in situ hybridization (FISH). In the first patient, a 4-month-old boy with developmental delay, hypotonia, growth retardation, coronal synostosis, mild hypertelorism, and bilateral club feet, we found a duplication of the Charcot-Marie-Tooth disease type 1A and Smith-Magenis syndrome (SMS) chromosome regions, inverted insertion of the Miller-Dieker lissencephaly syndrome region into the SMS region, and two microdeletions including a terminal deletion of 17p. The latter, together with a duplication of 21q22.3-qter detected by array CGH, are likely the unbalanced product of a translocation t(17;21)(p13.3;q22.3). In the second patient, an 8-year-old girl with mental retardation, short stature, microcephaly and mild dysmorphic features, we identified four submicroscopic interspersed 17p duplications. All 17 breakpoints were examined in detail by FISH analysis. We found that four of the breakpoints mapped within known low-copy repeats (LCRs), including LCR17pA, middle SMS-REP/LCR17pB block, and LCR17pC. Our findings suggest that the LCR burden in proximal 17p may have stimulated the formation of these CCRs and, thus, that genome architectural features such as LCRs may have been instrumental in the generation of these CCRs.
Collapse
Affiliation(s)
- L. E. L. M. Vissers
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - P. Stankiewicz
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX USA
| | - S. A. Yatsenko
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX USA
| | - E. Crawford
- Sentara Hospital Laboratories, Norfolk, VA USA
| | - H. Creswick
- Children’s Hospital of the King’s Daughters, Norfolk, VA USA
| | - V. K. Proud
- Children’s Hospital of the King’s Daughters, Norfolk, VA USA
| | - B. B. A. de Vries
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - R. Pfundt
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - C. L. M. Marcelis
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - J. Zackowski
- Children’s Hospital of the King’s Daughters, Norfolk, VA USA
| | - W. Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX USA
| | - A. Geurts van Kessel
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| | - J. R. Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX USA
- Texas Children’s Hospital, Houston, TX USA
| | - J. A. Veltman
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
| |
Collapse
|
23
|
Gallagher RE, Schachter-Tokarz EL, Zhou DC, Ding W, Kim SH, Sankoorikal BJ, Bi W, Livak KJ, Slack JL, Willman CL. Relapse of acute promyelocytic leukemia with PML-RARalpha mutant subclones independent of proximate all-trans retinoic acid selection pressure. Leukemia 2006; 20:556-62. [PMID: 16437139 PMCID: PMC1410817 DOI: 10.1038/sj.leu.2404118] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Relapse of acute promyelocytic leukemia (APL) following all-trans retinoic acid (ATRA) therapy has been associated with the acquisition of mutations in the high-affinity ATRA binding site in PML-RARalpha, but little information is available about the selection dynamics of the mutation-harboring subclones. In this study, 6/18 patients treated with sequential ATRA and chemotherapy on protocol INT0129 relapsed with complete replacement of the nonmutant pretreatment APL cell population by a PML-RARalpha mutant subclone. Two patients relapsed in proximity of ATRA treatment; however, in four patients there was a 6-48 month hiatus between the last ATRA treatment and relapse. The mutant subclones were not detectable in samples tested > or = 3 months before relapse at > or = 1 in 10(2) (10(-2)) sensitivity. In one patient, a functionally weak mutation was detected at 10(-4) sensitivity before therapy but only limited pre-relapse enrichment of the mutant subclone was observed on subsequent ATRA therapy. These results indicate that proximate ATRA selection pressure is frequently not the main determinant for the emergence of strongly dominant PML-RARalpha mutant subclones and suggest that APL subclones harboring PML-RARalpha mutations are predisposed to the acquisition of secondary genetic/epigenetic alterations that result in a growth/survival advantage.
Collapse
Affiliation(s)
- R E Gallagher
- Department of Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY 10467, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Price JC, Ziolko S, Klunk W, Mathis C, Lopresti B, Bi W, Hoge J, DeKosky S, Weissfeld L. Multivariate analysis of PIB PET imaging studies. Neuroimage 2006. [DOI: 10.1016/j.neuroimage.2006.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
|
25
|
Stankiewicz P, Inoue K, Bi W, Walz K, Park SS, Kurotaki N, Shaw CJ, Fonseca P, Yan J, Lee JA, Khajavi M, Lupski JR. Genomic disorders: genome architecture results in susceptibility to DNA rearrangements causing common human traits. Cold Spring Harb Symp Quant Biol 2004; 68:445-54. [PMID: 15338647 DOI: 10.1101/sqb.2003.68.445] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- P Stankiewicz
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas 77030, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Beillard E, Pallisgaard N, van der Velden VHJ, Bi W, Dee R, van der Schoot E, Delabesse E, Macintyre E, Gottardi E, Saglio G, Watzinger F, Lion T, van Dongen JJM, Hokland P, Gabert J. Evaluation of candidate control genes for diagnosis and residual disease detection in leukemic patients using 'real-time' quantitative reverse-transcriptase polymerase chain reaction (RQ-PCR) - a Europe against cancer program. Leukemia 2004; 17:2474-86. [PMID: 14562124 DOI: 10.1038/sj.leu.2403136] [Citation(s) in RCA: 660] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Real-time quantitative RT-PCR (RQ-PCR) is a sensitive tool to monitor minimal residual disease (MRD) in leukemic patients through the amplification of a fusion gene (FG) transcript. In order to correct variations in RNA quality and quantity and to calculate the sensitivity of each measurement, a control gene (CG) transcript should be amplified in parallel to the FG transcript. To identify suitable CGs, a study group within the Europe Against Cancer (EAC) program initially focused on 14 potential CGs using a standardized RQ-PCR protocol. Based on the absence of pseudogenes and the level and stability of the CG expression, three genes were finally selected: Abelson (ABL), beta-2-microglobulin (B2M), and beta-glucuronidase (GUS). A multicenter prospective study on normal (n=126) and diagnostic leukemic (n=184) samples processed the same day has established reference values for the CG expression. A multicenter retrospective study on over 250 acute and chronic leukemia samples obtained at diagnosis and with an identified FG transcript confirmed that the three CGs had a stable expression in the different types of samples. However, only ABL gene transcript expression did not differ significantly between normal and leukemic samples at diagnosis. We therefore propose to use the ABL gene as CG for RQ-PCR-based diagnosis and MRD detection in leukemic patients. Overall, these data are not only eligible for quantification of fusion gene transcripts, but also for the quantification of aberrantly expressed genes.
Collapse
Affiliation(s)
- E Beillard
- Department of Hematological Biology, Institute Paoli Calmettes, Marseille, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Alcorn JL, Huang HW, Bi W, Jenkins GN. 236 MOLECULAR MECHANISMS INVOLVED IN THE REGULATION OF HUMAN SURFACTANT PROTEIN B mRNA STABILITY BY GLUCOCORTICOIDS. J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
28
|
Gabert J, Beillard E, van der Velden VHJ, Bi W, Grimwade D, Pallisgaard N, Barbany G, Cazzaniga G, Cayuela JM, Cavé H, Pane F, Aerts JLE, De Micheli D, Thirion X, Pradel V, González M, Viehmann S, Malec M, Saglio G, van Dongen JJM. Standardization and quality control studies of ‘real-time’ quantitative reverse transcriptase polymerase chain reaction of fusion gene transcripts for residual disease detection in leukemia – A Europe Against Cancer Program. Leukemia 2003; 17:2318-57. [PMID: 14562125 DOI: 10.1038/sj.leu.2403135] [Citation(s) in RCA: 1106] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Detection of minimal residual disease (MRD) has proven to provide independent prognostic information for treatment stratification in several types of leukemias such as childhood acute lymphoblastic leukemia (ALL), chronic myeloid leukemia (CML) and acute promyelocytic leukemia. This report focuses on the accurate quantitative measurement of fusion gene (FG) transcripts as can be applied in 35-45% of ALL and acute myeloid leukemia, and in more than 90% of CML. A total of 26 European university laboratories from 10 countries have collaborated to establish a standardized protocol for TaqMan-based real-time quantitative PCR (RQ-PCR) analysis of the main leukemia-associated FGs within the Europe Against Cancer (EAC) program. Four phases were scheduled: (1) training, (2) optimization, (3) sensitivity testing and (4) patient sample testing. During our program, three quality control rounds on a large series of coded RNA samples were performed including a balanced randomized assay, which enabled final validation of the EAC primer and probe sets. The expression level of the nine major FG transcripts in a large series of stored diagnostic leukemia samples (n=278) was evaluated. After normalization, no statistically significant difference in expression level was observed between bone marrow and peripheral blood on paired samples at diagnosis. However, RQ-PCR revealed marked differences in FG expression between transcripts in leukemic samples at diagnosis that could account for differential assay sensitivity. The development of standardized protocols for RQ-PCR analysis of FG transcripts provides a milestone for molecular determination of MRD levels. This is likely to prove invaluable to the management of patients entered into multicenter therapeutic trials.
Collapse
Affiliation(s)
- J Gabert
- Department of Hematology Biology, Institut Paoli Calmettes, France.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Slack JL, Bi W, Livak KJ, Beaubier N, Yu M, Clark M, Kim SH, Gallagher RE, Willman CL. Pre-clinical validation of a novel, highly sensitive assay to detect PML-RARalpha mRNA using real-time reverse-transcription polymerase chain reaction. J Mol Diagn 2001; 3:141-9. [PMID: 11687597 PMCID: PMC1906965 DOI: 10.1016/s1525-1578(10)60665-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
We have developed a sensitive and quantitative reverse-transcription polymerase chain reaction (RT-PCR) assay for detection of PML-RARalpha, the fusion oncogene present as a specific marker in >99% of cases of acute promyelocytic leukemia (APL). The assay is linear over at least 5 orders of magnitude of input DNA or RNA, and detects as few as 4 copies of PML-RARalpha plasmid DNA. PML-RARalpha transcripts could be detected in mixtures containing 2 to 5 pg of RNA from fusion-containing cells in a background of 1 microg of RNA from PML-RARalpha-negative cells. Using 1.0 to 2.5 microg of input RNA, the sensitivity of the assay was between 10(-5) and 10(-6). Furthermore, determination of GAPDH copy number in each reaction allowed an accurate assessment of sample-to-sample variation in RNA quality and reaction efficiency, with consequent definition of a detection limit for each sample assayed. Using an internal calibrator, assay precision was high, with coefficients of variation between 10 and 20%. An interlaboratory study using coded samples demonstrated excellent reproducibility and high concordance between laboratories. This assay will be used to test the hypothesis that sensitive and quantitative measurement of leukemic burden, during or after therapy of APL, can stratify patients into discrete risk groups, and thereby serve as a basis for risk-adapted therapy in APL.
Collapse
Affiliation(s)
- J L Slack
- Department of Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Bi W, Huang W, Whitworth DJ, Deng JM, Zhang Z, Behringer RR, de Crombrugghe B. Haploinsufficiency of Sox9 results in defective cartilage primordia and premature skeletal mineralization. Proc Natl Acad Sci U S A 2001; 98:6698-703. [PMID: 11371614 PMCID: PMC34415 DOI: 10.1073/pnas.111092198] [Citation(s) in RCA: 428] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In humans, SOX9 heterozygous mutations cause the severe skeletal dysmorphology syndrome campomelic dysplasia. Except for clinical descriptions, little is known about the pathogenesis of this disease. We have generated heterozygous Sox9 mutant mice that phenocopy most of the skeletal abnormalities of this syndrome. The Sox9(+/-) mice died perinatally with cleft palate, as well as hypoplasia and bending of many skeletal structures derived from cartilage precursors. In embryonic day (E)14.5 heterozygous embryos, bending of radius, ulna, and tibia cartilages was already prominent. In E12.5 heterozygotes, all skeletal elements visualized by using Alcian blue were smaller. In addition, the overall levels of Col2a1 RNA at E10.5 and E12.5 were lower than in wild-type embryos. We propose that the skeletal abnormalities observed at later embryonic stages were caused by delayed or defective precartilaginous condensations. Furthermore, in E18.5 embryos and in newborn heterozygotes, premature mineralization occurred in many bones, including vertebrae and some craniofacial bones. Because Sox9 is not expressed in the mineralized portion of the growth plate, this premature mineralization is very likely the consequence of allele insufficiency existing in cells of the growth plate that express Sox9. Because the hypertrophic zone of the heterozygous Sox9 mutants was larger than that of wild-type mice, we propose that Sox9 also has a role in regulating the transition to hypertrophic chondrocytes in the growth plate. Despite the severe hypoplasia of cartilages, the overall organization and cellular composition of the growth plate were otherwise normal. Our results suggest the hypothesis that two critical steps of the chondrocyte differentiation pathway are sensitive to Sox9 dosage. First, an early step presumably at the stage of mesenchymal condensation of cartilage primordia, and second, a later step preceding the transition of chondrocytes into hypertrophic chondrocytes.
Collapse
Affiliation(s)
- W Bi
- Department of Molecular Genetics and Graduate Program in Genes and Development, M. D. Anderson Cancer Center, University of Texas, Houston, TX 77030, USA
| | | | | | | | | | | | | |
Collapse
|
31
|
Abstract
Real-time PCR methods with primers and a probe targeting conserved regions of the bacterial 16S ribosomal DNA (rDNA) revealed a larger amount of rDNA in blood specimens from healthy individuals than in matched reagent controls. However, the origins and identities of these blood-associated bacterial rDNA sequences remain obscure.
Collapse
Affiliation(s)
- S Nikkari
- Department of Microbiology and Immunology and Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | | | | | | | | |
Collapse
|
32
|
Hemstreet GP, Yin S, Ma Z, Bonner RB, Bi W, Rao JY, Zang M, Zheng Q, Bane B, Asal N, Li G, Feng P, Hurst RE, Wang W. Biomarker risk assessment and bladder cancer detection in a cohort exposed to benzidine. J Natl Cancer Inst 2001; 93:427-36. [PMID: 11259468 DOI: 10.1093/jnci/93.6.427] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Cancer screening with highly sensitive, specific biomarkers that reflect molecular phenotypic alterations is an attractive strategy for cancer control. We examined whether biomarker profiles could be used for risk assessment and cancer detection in a cohort of Chinese workers occupationally exposed to benzidine and at risk for bladder cancer. METHODS The cohort consisted of 1788 exposed and 373 nonexposed workers, followed from 1991 through 1997. We assayed urothelial cells from voided urine samples for DNA ploidy (expressed as the 5C-exceeding rate [DNA 5CER]), the bladder tumor-associated antigen p300, and a cytoskeletal protein (G-actin). Workers were stratified into different risk groups (high, moderate, and low risk) at each examination based on a predefined biomarker profile. For workers who developed bladder cancer, tumor risk assessment was analyzed from samples collected 6-12 months before the cancer diagnosis. The associations between risk group and subsequent development of bladder cancer were analyzed by Cox proportional hazards regression analysis and logistic analysis, after adjustment. All statistical tests were two-sided. RESULTS Twenty-eight bladder cancers were diagnosed in exposed workers and two in nonexposed workers. For risk assessment, DNA 5CER had 87.5% sensitivity, 86.5% specificity, an odds ratio (OR) of 46.2 (95% confidence interval [CI] = 8.1 to 867.0), and a risk ratio (RR) of 16.2 (95% CI = 7.1 to 37.0); p300 had 50.0% sensitivity, 97.9% specificity, an OR of 40.0 (95% CI = 9.0 to 177.8), and an RR of 37.9 (95% CI = 16.8 to 85.3). The risk of developing bladder cancer was 19.6 (95% CI = 8.0 to 47.9) times higher in workers positive for either the DNA 5CER or p300 biomarkers than in workers negative for both biomarkers and 81.4 (95% CI = 33.3 to 199.3) times higher in workers positive for both biomarkers. G-actin was a poor marker of individual risk. CONCLUSIONS Occupationally exposed workers at risk for bladder cancer can be individually stratified, screened, monitored, and diagnosed based on predefined molecular biomarker profiles.
Collapse
Affiliation(s)
- G P Hemstreet
- Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City 73104, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
With the goal of identifying master transcription factors that control the genetic program of differentiation of mesenchymal cells into chondrocytes, we first delineated a 48-bp chondrocyte-specific enhancer element in the gene for proalpha1(II) collagen (Col2a1), an early and abundant marker of chondrocytes. Our experiments have demonstrated that the HMG-box-containing transcription factor, Sox9 which binds and activates this enhancer element, is required for chondrocyte differentiation and for expression of a series of chondrocyte-specific marker genes including Col2a1, Col9a2, Col11a2 and Aggrecan. In the absence of Sox9 the block in differentiation occurs at the stage of mesenchymal condensation, suggesting the hypothesis that Sox9 might also control expression of cell surface proteins needed for mesenchymal condensation. Since Sox9 also contains a potent transcription activation domain, it is a typical transcription factor. Two other members of the Sox family, L-Sox5 and Sox6, also bind to the 48-bp Col2a1 enhancer and together with Sox9 activate this enhancer as well as the endogenous Col2a1 and aggrecan genes. L-Sox5 and Sox6 have a high degree of sequence identity to each other and are likely to have redundant functions. Except for the HMG-box, L-Sox5 and Sox6 have no similarity to Sox9 and, hence, are likely to have a complementary function to that of Sox9. Our experiments suggest the hypothesis that, like Sox9, Sox5 and Sox6 might also be needed for chondrocyte differentiation. Other experiments, have provided evidence that the Sox9 polypeptide and the Sox9 gene are targets of signaling molecules that are known to control discrete steps of chondrogenesis in the growth plate of endochondral bones. Protein kinase A (PKA) phosphorylation of Sox9 increases its DNA binding and transcriptional activity. Since PKA-phosphorylated-Sox9 is found in the prehypertrophic zone of the growth plate, the same location where the gene for the receptor of the parathyroid hormone-related peptide (PTHrP) is expressed and since PTHrP signaling is mediated by cyclic AMP, we have hypothesized that Sox9 is a target for PTHrP signaling. Other experiments have also shown that fibroblast growth factors (FGFs) increase the expression of Sox9 in chondrocytes in culture and that this activation is mediated by the mitogen-activated protein kinase pathway. These results favor the hypothesis that in achondroplasia, a disease caused by activating mutations in FGF receptor 3, there might also be an abnormally high Sox9 expression.
Collapse
Affiliation(s)
- B de Crombrugghe
- Department of Molecular Genetics, The University of Texas, M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
| | | | | | | | | | | |
Collapse
|
34
|
Dong J, Wang J, Hu Y, Lu S, Zhang Y, Bi W. [Treatment of spondylolisthesis with pedicle screw instrumentation and anterior or posterior lumbar interbody fusion]. Zhonghua Wai Ke Za Zhi 2000; 38:604-6. [PMID: 11832119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To investigate the treatment of spondylolisthesis with pedicle screw instrumentation and anterior or posterior lumbar interbody fusion. METHODS 26 patients, 14 males and 12 females, underwent spinal instrumentation with RF or SOCON instrumentation and anterior or posterior interbody fusion with TFC. Among them, 6 patients underwent RF instrumentation and posterior interbody fusion with TFC, 15 SOCON instrumentation and posterior interbody fusion with TFC, and 5 RF instrumentation and anterior interbody fusion with composite cortical ring. RESULTS All the patients were followed up for an average of 22 months (range 6 - 18 months) after operation. The reduction of spondylolisthesis was 88%, and the fusion rate 89%. There was no recurrence of spondylolisthesis. CONCLUSIONS High quality SOCON instrumentation may be reliable for the treatment of spondylolisthesis. Implantation of TFC into the interbody space can stabilize the fused segments, prevent the collapse of the interbody space, avoid bone resorption, remain or increase the heights of the interbody space, facilitate the union of the fused segments, and allow early mobilization.
Collapse
Affiliation(s)
- J Dong
- Department of Orthopaedic, General Hospital, People's Liberation Army, Beijing 100853, China
| | | | | | | | | | | |
Collapse
|
35
|
Kim YG, Bi W, Feliciano ES, Drake RR, Stambrook PJ. Ganciclovir-mediated cell killing and bystander effect is enhanced in cells with two copies of the herpes simplex virus thymidine kinase gene. Cancer Gene Ther 2000; 7:240-6. [PMID: 10770632 DOI: 10.1038/sj.cgt.7700113] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Delivery and expression of the herpes simplex virus thymidine kinase (HSVtk) gene in combination with the prodrug ganciclovir is currently being evaluated for the treatment of many types of cancer. After initial phosphorylation by HSVtk, cellular kinases generate the toxic triphosphate form of ganciclovir (GCV). To further define the role of GCV metabolism in cells expressing HSVtk, two human tumor cell lines, UMSCC29 and T98G, were transduced with HSVtk and screened for insertion of one or two copies of the viral transgene by Southern blot analysis. Both the relative capacities for incorporating labeled GCV and the levels of GCV metabolites were determined for each of the parental cell lines and their derivatives containing either one or two copies of the HSVtk gene. The efficiency of GCV killing and the magnitude of the bystander effect were compared for the single- and double-copy HSVtk cell lines. Consistently, cells that expressed two copies of HSVtk metabolized GCV more efficiently, were more sensitive to GCV, and demonstrated improved bystander killing relative to single-copy HSVtk cells. The implications of these results for future and current therapies employing HSVtk and GCV are discussed.
Collapse
Affiliation(s)
- Y G Kim
- Department of Cell Biology, Neurobiology, and Anatomy, University of Cincinnati College of Medicine, Ohio 45267-0521, USA
| | | | | | | | | |
Collapse
|
36
|
Jin W, Huang ES, Bi W, Cote GJ. Redundant intronic repressors function to inhibit fibroblast growth factor receptor-1 alpha-exon recognition in glioblastoma cells. J Biol Chem 1999; 274:28035-41. [PMID: 10488155 DOI: 10.1074/jbc.274.39.28035] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The human fibroblast growth factor receptor-1 primary transcript is alternatively processed to produce receptor forms that vary in their affinity for fibroblast growth factor. The inclusion of a single exon (alpha) in normal brain glial cells produces a low affinity form of the receptor. Recognition of the alpha-exon is dysregulated during neoplastic transformation of glial cells to produce a high affinity receptor form. In this study, we have identified a second intronic repressor of RNA splicing located approximately 250 nucleotides upstream of the alpha-exon. Deletion or mutation of this sequence resulted in a significant increase in exon recognition in glioblastoma cells. This intronic repressor was found to share significant sequence homology with an intronic repressor element located downstream of the alpha-exon. The two repressor elements are functionally redundant in that they are capable of inhibiting alpha-exon recognition when positioned upstream or downstream of the exon. Finally, the elements were found to mediate enhanced exclusion of an unrelated exon, but only the repressors were placed flanking the exon. However, under these conditions, the cell-specific exon exclusion was no longer maintained. These results suggest that although the alpha-exon inclusion is actively repressed in glioblastomas, the absence of trans-activators appears to be key to the production of the high affinity form of fibroblast growth factor receptor-1 in glioblastomas.
Collapse
Affiliation(s)
- W Jin
- Section of Endocrine Neoplasia and Hormonal Disorders, Department of Medical Specialties, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
| | | | | | | |
Collapse
|
37
|
Xu D, Zhan A, Feng W, Liu J, Zhang C, Bi W. Hyperplastic callus in osteogenesis imperfecta. Chin Med J (Engl) 1999; 112:764-6. [PMID: 11601292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Affiliation(s)
- D Xu
- Department of Radiology, Affiliated Hospital of Qingdao Medical College, Qingdao 266003, China.
| | | | | | | | | | | |
Collapse
|
38
|
Bi W, Drake CJ, Schwarz JJ. The transcription factor MEF2C-null mouse exhibits complex vascular malformations and reduced cardiac expression of angiopoietin 1 and VEGF. Dev Biol 1999; 211:255-67. [PMID: 10395786 DOI: 10.1006/dbio.1999.9307] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The MEF2 family of transcription factors has been implicated in transcriptional regulation in a number of different cell types. Targeted deletion of the MEF2C gene, in particular, revealed its importance for early cardiogenesis (Q. Lin et al., 1997, Science 276, 1404-1407). We report here that this deletion also resulted in vascular anomalies characterized by extreme variability in lumen size and defects in remodeling. While primary vascular networks formed in the yolk sac of the mutants, they failed to remodel into more complex vascular structures. Likewise, although the primordia of the dorsal aortae formed normally, anomalies were observed in these vessels later in development. Dorsal and anterior to the heart, the aortae exhibited abnormally small lumens, as did the anterior cardinal veins and intersegmental arteries. In contrast, the dorsal aortae and intersegmental arteries caudal to the heart were grossly enlarged. Cranial vessels were also enlarged and less branched than normal. Endocardiogenesis in the mutant was abnormal with the endothelial cells exhibiting a number of aberrant phenotypes. These endocardial defects were accompanied by a notable reduction in angiopoietin 1 and VEGF mRNA production by the myocardium, indicating that MEF2C is required for myocardial expression of these important endothelial-directed cytokines and thus for correct endocardial morphogenesis.
Collapse
Affiliation(s)
- W Bi
- Division of Cardiology, University of Texas Medical School at Houston, Houston, Texas, 77030, USA
| | | | | |
Collapse
|
39
|
Abstract
Chondrogenesis results in the formation of cartilages, initial skeletal elements that can serve as templates for endochondral bone formation. Cartilage formation begins with the condensation of mesenchyme cells followed by their differentiation into chondrocytes. Although much is known about the terminal differentiation products that are expressed by chondrocytes, little is known about the factors that specify the chondrocyte lineage. SOX9 is a high-mobility-group (HMG) domain transcription factor that is expressed in chondrocytes and other tissues. In humans, SOX9 haploinsufficiency results in campomelic dysplasia, a lethal skeletal malformation syndrome, and XY sex reversal. During embryogenesis, Sox9 is expressed in all cartilage primordia and cartilages, coincident with the expression of the collagen alpha1(II) gene (Col2a1) . Sox9 is also expressed in other tissues, including the central nervous and urogenital systems. Sox9 binds to essential sequences in the Col2a1 and collagen alpha2(XI) gene (Col11a2) chondrocyte-specific enhancers and can activate these enhancers in non-chondrocytic cells. Here, Sox9 is identified as a regulator of the chondrocyte lineage. In mouse chimaeras, Sox9-/- cells are excluded from all cartilages but are present as a juxtaposed mesenchyme that does not express the chondrocyte-specific markers Col2a1, Col9a2, Col11a2 and Agc. This exclusion occurred cell autonomously at the condensing mesenchyme stage of chondrogenesis. Moreover, no cartilage developed in teratomas derived from Sox9-/- embryonic stem (ES) cells. Our results identify Sox9 as the first transcription factor that is essential for chondrocyte differentiation and cartilage formation.
Collapse
Affiliation(s)
- W Bi
- Department of Molecular Genetics, The University of Texas, M.D. Anderson Cancer Center, Houston 77030, USA
| | | | | | | | | |
Collapse
|
40
|
Jin W, Bi W, Huang ES, Cote GJ. Glioblastoma cell-specific expression of fibroblast growth factor receptor-1beta requires an intronic repressor of RNA splicing. Cancer Res 1999; 59:316-9. [PMID: 9927039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The fibroblast growth factor receptor-1 (FGFR-1) primary transcript is alternatively processed to produce receptors that vary in their ligand affinity and specificity. A high affinity form of this receptor--FGFR-1beta--that lacks the alpha exon is observed on the neoplastic transformation of glial cells. In this study, we have identified a 62-bp sequence located 97 bp downstream from the alpha exon that is required for the exclusion of this exon in a human glioblastoma cell line. Deletion or mutation of this sequence is sufficient to allow enhanced inclusion of the alpha exon or a heterologous exon in glioblastoma cells. Therefore, it would appear that this sequence element plays a key role in the glioblastoma-specific splicing to form FGFR-1beta mRNA.
Collapse
Affiliation(s)
- W Jin
- Department of Medical Specialties, The University of Texas, M.D. Anderson Cancer Center, Houston 77030, USA
| | | | | | | |
Collapse
|
41
|
Cai X, Wang J, Hu Y, Lu S, Bi W, Li N, Chuang J. [Biological mechanism of macrophage activation by wear particles at the bone-implant interface]. Zhonghua Wai Ke Za Zhi 1999; 37:53-6, 2. [PMID: 11829780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To observe the response of membrane Ca(2+) channel of macrophage-like cells (MCs) to wear particles and analyze the cytoplasmic [Ca(2+)]i change in macrophage activation at the bone-implant interface. METHODS The synoviocyte system of normal hip joint was established in vitro. Immunohistochemical technique (SABC) with CD68 Mab was used to differentiate MCs and fibroblast-like cells (FCs) in the system, and the time when MCs begin to perform phagocytosis was determined by SEM. 1.5 mg/ml (W/V) Ti alloy, Co-Cr alloy or UHMWPE particles suspension was added into the system to monitor the [Ca(2+)]i change in the MCs by confocal laser scanning microscope (CLSM). RESULTS Phagocytosis of MCs happened after 6 hours, but within 1 hour the Ca(2+) channel of their cell membrane opened for 1 - 6 times and caused rapid and transient pulses of [Ca(2+)]i in cytoplasm after different period of incubation. There was no significant difference between times or range of the [Ca(2+)]i pulse (P > 0.05). The group of UHMWPE particles had the longest incubation period (P < 0.05), but the interval of pulses was shorter than that in the group of Co-Cr alloy particles (P < 0.05). [Ca(2+)]i pulses still appeared when MCs were incubated by indomethecin (P > 0.05), but the phenomenon could be blocked by nimodipin. CONCLUSIONS Activation of macrophages at the bone-implant-interface could happen before they phagocytose wear particles. The primary switch-on mechanism of osteolysis mediated by cytokines at the bone-implant interface may be the opening of membrane Ca(2+) channel and pulse-like Ca(2+) influx of macrophages when stimulated by wear particles.
Collapse
Affiliation(s)
- X Cai
- General Hospital, Chinese People's Liberation Army, Beijing 100853
| | | | | | | | | | | | | |
Collapse
|
42
|
Abstract
We have investigated the intracellular localization of proteolytic cleavage products encoded in the 5' portion of mouse hepatitis virus (MHV) gene 1. Immunofluorescent labeling of cells with an antiserum which recognizes p28, the ORF1a N-terminal cleavage product, resulted in widespread somewhat granular cytoplasmic staining, indicating that this protein is widely distributed in the cytoplasm of MHV-infected, but not control uninfected cells. Immunofluorescent staining of infected cells with antisera which recognize the downstream polypeptides, p65, p240 and p290 labeled discrete vesicular perinuclear structures. Double immunofluorescent labeling of BHK cells expressing the MHV receptor (BHK(MHVR1)) and infected with MHV-A59 with a Golgi-specific anti-mannosidase II monoclonal antibody and with antiserum recognizing each of these anti-MHV ORF1a polypeptides, showed that the p240 and p290 polypeptides were localized in discrete vesicular structures that overlapped the Golgi complex. Labeling with antibodies specific for p65 colocalized with the Golgi region, and showed staining of the perinuclear cytoplasm as well. Plasmids containing sequences contained in the first 6.75 kb of ORF1a have been expressed using the coupled vaccinia virus-T7 polymerase system. Immunofluorescent labeling of transfectants with the anti-ORF1a antisera showed patterns of antigen distribution similar to those observed in cells infected with MHV-A59. A deletion analysis with constructs containing only portions of the ORF1a sequence indicated that 303 amino acids containing the first papain-like protease domain (PLP-1) was sufficient to associate this protein with the Golgi.
Collapse
Affiliation(s)
- W Bi
- Department of Pathology and Laboratory Medicine, University of Texas Health Sciences Center, Houston 77225, USA
| | | | | | | | | | | | | |
Collapse
|
43
|
Marcucci G, Livak KJ, Bi W, Strout MP, Bloomfield CD, Caligiuri MA. Detection of minimal residual disease in patients with AML1/ETO-associated acute myeloid leukemia using a novel quantitative reverse transcription polymerase chain reaction assay. Leukemia 1998; 12:1482-9. [PMID: 9737700 DOI: 10.1038/sj.leu.2401128] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The AML1/ETO fusion transcript can be detected by reverse transcription polymerase chain reaction (RT-PCR) in patients with t(8;21)-associated acute myeloid leukemia (AML) in long-term complete remission (CR). Quantitation of the amount of the fusion transcript during CR may therefore be more predictive of cure or relapse than a simple qualitative assessment. Real Time PCR, a fluorometric-based technique, allows simple and rapid quantitation of a target sequence during the extension phase of PCR amplification, in contrast to end-point quantitative methods. Six patients with t(8;21)(q22;q22) AML, who achieved CR were studied by Real Time RT-PCR at different time intervals following diagnosis and high-dose cytarabine and anthracycline-based induction therapy. Five patients had a diagnostic bone marrow (BM) sample available for molecular analysis. Each patient showed > or = 10(3) copies of the AML1/ETO fusion transcript at diagnosis, and each showed a 2- to 4-log decrease in copy number following successful induction chemotherapy. This is comparable to the log-fold reduction in leukemic blasts that is thought to occur in patients successfully cytoreduced into CR by induction chemotherapy. The sixth patient showed a relatively high copy number immediately following successful remission induction chemotherapy, which continued to increase during early CR and was later followed by relapse. Real Time RT-PCR appears to offer advantages over previously used quantitative RT-PCR methods by providing absolute quantitation of the target sequence, expanding the dynamic range of quantitation to over six orders of magnitude, eliminating the post-PCR processing, and reducing labor and carryover contamination. These features make this an attractive method to prospectively evaluate the prognostic value of AML1/ETO fusion transcript quantitation in a larger patient population with t(8;21)(q22;q22) AML in CR.
Collapse
MESH Headings
- Acute Disease
- Antineoplastic Combined Chemotherapy Protocols/therapeutic use
- Chromosomes, Human, Pair 21/genetics
- Chromosomes, Human, Pair 8/genetics
- Core Binding Factor Alpha 2 Subunit
- Feasibility Studies
- Humans
- Leukemia, Myeloid, Acute/diagnosis
- Leukemia, Myeloid, Acute/drug therapy
- Leukemia, Myeloid, Acute/genetics
- Neoplasm, Residual
- Oncogene Proteins, Fusion
- Polymerase Chain Reaction/methods
- RUNX1 Translocation Partner 1 Protein
- Recombinant Fusion Proteins/analysis
- Remission Induction
- Transcription Factors/analysis
- Translocation, Genetic/genetics
Collapse
Affiliation(s)
- G Marcucci
- Department of Internal Medicine, Comprehensive Cancer Center at The Ohio State University, Columbus 43210, USA
| | | | | | | | | | | |
Collapse
|
44
|
Jin W, Huang ES, Bi W, Cote GJ. Exon sequence is required for regulated RNA splicing of the human fibroblast growth factor receptor-1 alpha-exon. J Biol Chem 1998; 273:16170-6. [PMID: 9632672 DOI: 10.1074/jbc.273.26.16170] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alternative RNA processing of the human fibroblast growth factor receptor-1 transcript results in receptor forms that vary in their affinity for fibroblast growth factor. An alternative RNA processing event involving recognition of the alpha-exon is deregulated during neoplastic transformation of glial cells. We have previously established a splicing reporter/transfection cell culture model system to identify sequences involved in recognition of this exon. In this study, the system was used to identify two sequence elements that differentially function to regulate splicing of this exon. Exclusion of the alpha-exon in glioblastoma cells specifically required the downstream intron sequence comprising the 5'-splice site. Replacement or mutation of this sequence increasing complementarity to U1 RNA resulted in enhanced exon recognition in SNB-19 glioblastoma cells. Sequences within the exon were found to be required for alpha-exon inclusion. Deletion and gain-of-function experiments identified a 69-nucleotide exon sequence that was specifically required for alpha-exon inclusion. These studies indicate that multiple sequences are required for the regulated recognition of the alpha-exon.
Collapse
Affiliation(s)
- W Jin
- Section of Endocrinology, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
| | | | | | | |
Collapse
|
45
|
Abstract
Proof-reading PCR (PR-PCR) is designed to detect known mutations within genomic DNA. It differs from standard PCR approaches in that one of the two primers has its 3' end aligned with a putative mutation site, and has its 3'-OH replaced by a blocking group. Distinguishing a mutant gene from wild-type depends upon preferential removal of the blocked 3' terminal nucleotide by the polymerase proof-reading activity when it is mismatched with the template. Preferential removal of the blocked nucleotide allows subsequent extension and selective amplification, and provides the basis for distinguishing mutant from normal genes. This method has been used here to detect a transition mutation within the P53 gene of HaCaT cells with verification by direct sequencing of the selectively amplified DNA.
Collapse
Affiliation(s)
- W Bi
- Department of Cell Biology, Neurobiology and Anatomy, University of Cincinnati, College of Medicine, PO Box 670521, Cincinnati, OH 45267-0521, USA
| | | |
Collapse
|
46
|
Affiliation(s)
- W Bi
- Department of Cell Biology, Neurobiology and Anatomy, University of Cincinnati, College of Medicine, Ohio 45267-0521, USA
| | | |
Collapse
|
47
|
Abstract
CBF is a heterotrimeric protein that binds to DNA containing CCAAT motifs. Here we have analyzed interactions of recombinant CBF with DNA using hydroxyl radical footprinting and methylation interference assays. In the CBF-DNA complex, three separate DNA regions are protected from hydroxyl radical cleavage, one located over and immediately adjacent to the CCAAT motif itself and the other two located on both sides of the CCAAT motif. The methylation interference assay showed, however, that only in the CCAAT motif region methylation of bases was able to interfere with the formation of a CBF-DNA complex, suggesting that CBF makes sequence-specific contacts only in the CCAAT motif region. To further determine the specific DNA sequences necessary for CBF binding, we employed a polymerase chain reaction-mediated random binding site selection method. This analysis showed that CBF binding to DNA requires the CCAAT sequence and other specific sequences immediately flanking both ends of the CCAAT motif. We also showed that the nature of the flanking nucleotide sequences affects the affinity of CBF for DNA. Interestingly, most of the CCAAT motifs present in various higher eukaryotic promoters correspond to the CBF binding sites that were selected, consistent with the hypothesis that these motifs are binding sites for CBF and, hence, that CBF could regulate transcription of numerous eukaryotic genes.
Collapse
Affiliation(s)
- W Bi
- Department of Molecular Genetics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
| | | | | | | | | |
Collapse
|
48
|
Abstract
We describe a simple approach for detecting known mutations in genomic DNA. The strategy entails a DNA amplification reaction that combines the use of thermostable DNA polymerase and ligase, and that has been designated the Combined Chain Reaction (CCR). CCR consists of four phases: denaturation, annealing, elongation and ligation. Unlike most PCR-based mutation detection systems it relies on mismatch between primer and template at the primer 5'ends. It is rapid and simple, and requires neither the use of radioactivity, nor polyacrylamide gel electrophoresis, nor autoradiography for mutation detection at the single base-pair level.
Collapse
Affiliation(s)
- W Bi
- Department of Cell Biology, Neurobiology and Anatomy, University of Cincinnati, College of Medicine, Cincinnati, OH 45267-0521, USA
| | | |
Collapse
|
49
|
Bi W, Kim YG, Feliciano ES, Pavelic L, Wilson KM, Pavelic ZP, Stambrook PJ. An HSVtk-mediated local and distant antitumor bystander effect in tumors of head and neck origin in athymic mice. Cancer Gene Ther 1997; 4:246-52. [PMID: 9253510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The "bystander effect," produced by ganciclovir-mediated killing of cells transduced with a herpes simplex virus thymidine kinase (HSVtk) gene, defines the cooperative killing of non-HSVtk-transduced cells. In vitro, a major contributor to this phenomenon is metabolic cooperation involving transfer of cytotoxic small molecules between cells via gap junctions. In this study, the bystander effect was assessed in vivo using cells of oral squamous cell carcinoma origin. Mixtures of HSVtk+ and HSVtk- tumor cells were implanted subcutaneously in the left flank of nude mice, and naive HSVtk- cells were implanted subcutaneously in the right flank. When tumors attained a size of 0.5 to 1 cm, the animals were treated with ganciclovir on a daily basis. The tumors comprised of mixed cells in the left flank resolved, consistent with a predicted bystander effect. The naive tumors in the right flank either resolved or became cytostatic showing little further growth compared to controls. Similar results were obtained when naive tumors were grown in both flanks and the tumor in the left flank received intratumoral injection of HSVtk retroviral producer cells or PA317 (HSVtk+) packaging cells, but not parental NIH 3T3 cells. Concomitant treatment with dexamethasone impaired the antitumor effect on the contralateral side. When these experiments were performed in SCID-Beige mice, there was a reduced antitumor effect on the ipsilateral flank and no antitumor response in the contralateral flank. Together with histology of regressing tumors, which showed an infiltration of lymphoid cells, these results are suggestive of an immune-related antitumor response that could account for the distant bystander effect.
Collapse
Affiliation(s)
- W Bi
- Department of Cell Biology, Neurobiology and Anatomy, University of Cincinnati, College of Medicine 45267-0521, USA
| | | | | | | | | | | | | |
Collapse
|
50
|
Lu X, Bi W, Li Z. [CT analysis of hepatic metastases]. Zhonghua Zhong Liu Za Zhi 1997; 19:56-8. [PMID: 10743058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
OBJECTIVE To describe the manifestations of the hepatic metastases. To investigate the value of CT examination in diagnosis of hepatic metastases. METHOD CT radiographs of 90 patients with hepatic metastases were studied retrospectively. The tumor number, size, density, shape, spreading in the hepatic parenchyma were analyzed. The size of liver and spleen was measured. RESULTS Three or more metastatic nodules spreading in the hepatic parenchyma were found in 65 (72%) cases. Two nodules were shown in 6 (7%) cases. 19(21%) cases had only single nodule. 29 of the metastatic deposits located in the hepatic parenchyma near the liver edge. The size of metastatic nodules varied from 0.5 cm to 14 cm. In 87 cases, the density of metastatic nodules was lower than the surround liver parenchyma. In 3 cases of diffuse fatty liver, the metastatic deposits appeared as higher CT density nodules. Central necrosis of the tumor foci was seen in 44 cases. Striking hepatomegaly was noted in 31 cases with widespread nodules. In 26 cases which had one and two nodules, the shape of the liver was normal. In 45 cases, the primary tumour was found by CT at the same time. CONCLUSION The CT findings of hepatic metastases differ. Multiple nodules disseminating in liver parenchyma is the general sign. Tiny nodules without other clinical signs can be detected by CT.
Collapse
Affiliation(s)
- X Lu
- Department of Radiology, Affiliated Hospital of Qingdao Medical College
| | | | | |
Collapse
|