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Qi TM, Wang FR, Fan CM, Liu LM, Zhou JY, Lin XC, Suonan AX. Repairing effects of liraglutide on spinal cord injury in rats via PI3K/AKT/ENOS signaling pathway. J BIOL REG HOMEOS AG 2020; 34:2083-2089. [PMID: 33198445 DOI: 10.23812/20-263-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- T M Qi
- Department of Orthopaedics, Qinghai Provincial People's Hospital, Xining, China
| | - F R Wang
- Department of Orthopaedics, Qinghai Provincial People's Hospital, Xining, China
| | - C M Fan
- Department of Gastroenterology, The Fifth People's Hospital of Qinghai Province, Xining, China
| | - L M Liu
- Department of Orthopaedics, Qinghai Provincial People's Hospital, Xining, China
| | - J Y Zhou
- Department of Orthopaedics, Qinghai Provincial People's Hospital, Xining, China
| | - X C Lin
- Department of Orthopaedics, Qinghai Provincial People's Hospital, Xining, China
| | - A X Suonan
- Department of Orthopaedics, Qinghai Provincial People's Hospital, Xining, China
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Yan LR, Fan CM, Zhang J. [Pharmacological treatment of hypertrophic cardiomyopathy: novel perspectives]. Zhonghua Xin Xue Guan Bing Za Zhi 2018; 46:502-505. [PMID: 29925191 DOI: 10.3760/cma.j.issn.0253-3758.2018.06.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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Hong F, Fan CM. [Research progress on LEOPARD syndrome]. Zhonghua Xin Xue Guan Bing Za Zhi 2016; 44:1006-1009. [PMID: 28056229 DOI: 10.3760/cma.j.issn.0253-3758.2016.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Yang HM, Song XL, Yang TL, Liang ZH, Fan CM, Hao XG. Electrochemical synthesis of flower shaped morphology MOFs in an ionic liquid system and their electrocatalytic application to the hydrogen evolution reaction. RSC Adv 2014. [DOI: 10.1039/c3ra47744d] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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Abstract
PURPOSE To evaluate the effect of verteporfin therapy (Visudyne) on age-related macular degeneration (AMD) in Chinese patients. The baseline characteristic and the visual outcome will be compared with the treatment of AMD with photodynamic therapy study (TAP) and verteporfin in photodynamic therapy study (VIP). DESIGN Retrospective comparative case series. METHOD We recruited patients >50 years old, with best-corrected visual acuity >20/200 and fluorescein angiography documenting subfoveal either predominantly classic with greatest linear dimension <5400 mum or pure occult choroidal neovascularization (CNV) secondary to AMD. We applied non-thermal laser to the lesion 15 min after visudyne infusion as described in TAP study. Patients were followed up with fluorescein angiography every 3 months. Additional treatment would be offered if there was evidence of recurrence of CNV. OUTCOME MEASURE Baseline characteristic and visual outcome. RESULT In all, 46 eyes of 42 patients were enrolled at our centre from July 2002 to June 2003. They comprised 11 eyes with predominantly classic lesions and 35 eyes with pure occult lesion. The mean number of treatment sessions given was 2.9 in the first year. At the 12-month examination, there were 63 and 29% of patients showing visual improvement in predominantly classic and occult groups, respectively, while there were only 16% of patients in the TAP study and 12% of patients in the VIP study showing visual improvement in the same period. CONCLUSION Verteporfin therapy for subfoveal CNV is beneficial to Chinese patients with AMD at first year. The visual result seems to be better than that observed in Caucasian patients.
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Affiliation(s)
- N Yang
- Department of Ophthalmology, Tuen Mun Hospital, HKSAR, Tuen Mun, NT, Hong Kong.
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Wicky S, Fan CM, Geller SC, Greenfield A, Santilli J, Waltman AC. MR angiography of endoleak with inconclusive concomitant CT angiography. AJR Am J Roentgenol 2003; 181:736-8. [PMID: 12933471 DOI: 10.2214/ajr.181.3.1810736] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- S Wicky
- Department of Radiology, Massachusetts General Hospital, 55 Fruit St. Boston, MA 02114, USA
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Abstract
This study aimed at improving the photocatalytic (PC) oxidation of humic acids (HA) in TiO2 suspensions by adding cationic ion such as calcium or magnesium. A set of tests was first conducted in the dark to study the adsorption of HA onto TiO2 in suspensions at different pH and calcium concentrations. The experiment demonstrated that the adsorption of HA onto the TiO2 particles was either pH-dependent or calcium strength-dependent due to electrostatic interaction and calcium ion bridging. The photodegradation of HA in the presence of UV irradiation was investigated as a function of pH and the concentration of calcium and magnesium ions. The results showed that the adsorption behavior between HA and TiO2 played a very important role during the PC oxidation process. The PC oxidation could be enhanced at neutral pH by increasing the cation strength. The kinetics of HA PC degradation in TiO2 suspensions with different initial concentrations was also studied using the Langmuir-Hinshelwood model.
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Affiliation(s)
- X Z Li
- Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hunghom, Kowloon.
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Abstract
Humic acid (HA) is one of natural organics existing in water supply as a precursor of trihalomethanes formation in chlorination. The photo-degradation of HA in aqueous solution by photoelectrocatalytic (PEC) oxidation using a Ti/TiO2 mesh electrode was investigated in terms of UV absorbance at 254 nm, colour and TOC concentration. The key factors affecting the PEC oxidation efficiency were studied, including the concentration of electrolyte, electrical bias applied. pH value of HA solution, the intensity of incident light and the area of Ti/TiO2 mesh photoelectrodes. The first-order kinetic model was applied to describe the PEC oxidation, in which the kinetic constant k was verified by the experimental data as a function of the concentration of electrolyte, light intensity, the area of Ti/TiO2 mesh electrode and the voltage of electrical bias applied. It was found that there was an optimal bias voltage of 1.63 V and low pH value was favourable for TOC removal in HA solution. Our investigation showed that PEC oxidation was a convenient way to mineralise the organic matters with high efficiency.
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Affiliation(s)
- X Z Li
- Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hunghom, Kowloon.
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Lee CS, Buttitta L, Fan CM. Evidence that the WNT-inducible growth arrest-specific gene 1 encodes an antagonist of sonic hedgehog signaling in the somite. Proc Natl Acad Sci U S A 2001; 98:11347-52. [PMID: 11572986 PMCID: PMC58732 DOI: 10.1073/pnas.201418298] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.5] [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] [Received: 07/16/2001] [Accepted: 08/08/2001] [Indexed: 01/26/2023] Open
Abstract
The dorsal-ventral polarity of the somite is controlled by antagonistic signals from the dorsal neural tube/surface ectoderm, mediated by WNTs, and from the ventral notochord, mediated by sonic hedgehog (SHH). Each factor can act over a distance greater than a somite diameter in vitro, suggesting they must limit each other's actions within their own patterning domains in vivo. We show here that the growth-arrest specific gene 1 (Gas1), which is expressed in the dorsal somite, is induced by WNTs and encodes a protein that can bind to SHH. Furthermore, ectopic expression of Gas1 in presomitic cells attenuates the response of these cells to SHH in vitro. Taken together, these data suggest that GAS1 functions to reduce the availability of active SHH within the dorsal somite.
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Affiliation(s)
- C S Lee
- Department of Embryology, Carnegie Institution of Washington, 115 West University Parkway, Baltimore, MD 21210, USA
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Rehring TF, Brewster DC, Kaufman JA, Fan CM, Geller SC. Regression of perianeurysmal fibrosis and ureteral dilation following endovascular repair of inflammatory abdominal aortic aneurysm. Ann Vasc Surg 2001; 15:591-3. [PMID: 11665449 DOI: 10.1007/s10016-001-0019-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [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: 10/28/2022]
Abstract
An inflammatory component to abdominal aortic aneurysms (AAA) is thought to occur in approximately 5% of cases. Accompanying ureteral entrapment may be involved in 20% of these. Transabdominal repair of inflammatory AAA with ureterolysis may result in increased complications. Many authorities have recommended a retroperitoneal approach to decrease dissection. Similarly, an endovascular approach has been utilized. We report here the results of a patient with an inflammatory AAA with bilateral ureteral obstruction successfully treated with endovascular stent graft repair and bilateral ureteral stents with exclusion of the aneurysm and resolution of hydronephrosis.
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Affiliation(s)
- T F Rehring
- Division of Vascular Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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11
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Abstract
Postnatal cerebellum development involves the generation of granule cells and Bergmann glias (BGs). The granule cell precursors are located in the external germinal layer (EGL) and the BG precursors are located in the Purkinje layer (PL). BGs extend their glial fibers into the EGL and facilitate granule cells' inward migration to their final location. Growth arrest specific gene 1 (Gas1) has been implicated in inhibiting cell-cycle progression in cell culture studies (G. Del Sal et al., 1992, Cell 70, 595--607). However, its growth regulatory function in the CNS has not been described. To investigate its role in cerebellar growth, we analyzed the Gas1 mutant mice. At birth, wild-type and mutant mice have cerebella of similar size; however, mature mutant cerebella are less than half the size of wild-type cerebella. Molecular and cellular examinations indicate that Gas1 mutant cerebella have a reduced number of granule cells and BG fibers. We provide direct evidence that Gas1 is required for normal levels of proliferation in the EGL and the PL, but not for their differentiation. Furthermore, we show that Gas1 is specifically and coordinately expressed in both the EGL and the BGs postnatally. These results support Gas1 as a common genetic component in coordinating EGL cell and BG cell proliferation, a link which has not been previously appreciated.
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Affiliation(s)
- Y Liu
- Department of Embryology, Carnegie Institution of Washington, 115 West University Parkway, Baltimore, Maryland 21210, USA
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Abstract
During eye development, retinal pigmented epithelium (RPE) and neural retina (NR) arise from a common origin, the optic vesicle. One of the early distinctions of RPE from NR is the reduced mitotic activity of the RPE. Growth arrest specific gene 1 (Gas1) has been documented to inhibit cell cycle progression in vitro (G. Del Sal et al., 1992, Cell 70, 595--607). We show here that the expression pattern of Gas1 in the eye supports its negative role in RPE proliferation. To test this hypothesis, we generated a mouse carrying a targeted mutation in the Gas1 locus. Gas1 mutant mice have microphthalmia. Histological examination revealed that the remnant mutant eyes are ingressed from the surface with minimal RPE and lens, and disorganized eyelid, cornea, and NR. Analysis of the Gas1 mutant indicates that there is overproliferation of the outer layer of optic cup (E10.5) immediately after the initial specification of the RPE. This defect is specific to the ventral region of the RPE. Using molecular markers for RPE (Mi and Tyrp2) and NR (Math5), we demonstrate that there is a gradual loss of Mi and Tyrp2 expression and an appearance of Math5 expression in the mutant ventral RPE region, indicating that this domain becomes respecified to NR. This "ectopic" NR develops as a mirror image of the normal NR and is entirely of ventral identity. Our data not only support Gas1's function in regulating cell proliferation, but also uncover an unexpected regional-specific cell fate change associated with dysregulated growth. Furthermore, we provide evidence that the dorsal and ventral RPEs are maintained by distinct genetic components.
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Affiliation(s)
- C S Lee
- Department of Embryology, Carnegie Institution of Washington, 115 West University Parkway, Baltimore, Maryland 21210, USA
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Michaud JL, Boucher F, Melnyk A, Gauthier F, Goshu E, Lévy E, Mitchell GA, Himms-Hagen J, Fan CM. Sim1 haploinsufficiency causes hyperphagia, obesity and reduction of the paraventricular nucleus of the hypothalamus. Hum Mol Genet 2001; 10:1465-73. [PMID: 11448938 DOI: 10.1093/hmg/10.14.1465] [Citation(s) in RCA: 245] [Impact Index Per Article: 10.7] [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: 11/12/2022] Open
Abstract
The bHLH-PAS transcription factor SIM1 is required for the development of the paraventricular nucleus (PVN) of the hypothalamus. Mice homozygous for a null allele of Sim1 (Sim1(-/-)) lack a PVN and die perinatally. In contrast, we show here that Sim1 heterozygous mice are viable but develop early-onset obesity, with increased linear growth, hyperinsulinemia and hyperleptinemia. Sim1(+/-) mice are hyperphagic but their energy expenditure is not decreased, distinguishing them from other mouse models of early-onset obesity such as deficiencies in leptin and melanocortin receptor 4. Quantitative histological comparison with normal littermates showed that the PVN of Sim1(+/-) mice contains on average 24% fewer cells without a selective loss of any identifiable major cell type. Since acquired lesions in the PVN also induce increased appetite without a decrease in energy expenditure, we propose that abnormalities of PVN development cause the obesity of Sim1(+/-) mice. Severe obesity was described recently in a patient with a balanced translocation disrupting SIM1. Pathways controlling the development of the PVN thus have the potential to cause obesity in both mice and humans.
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Affiliation(s)
- J L Michaud
- Research Center, Hôpital Sainte-Justine, 3175 Côte Sainte-Catherine, Montreal, Quebec, H3T 1C5, Canada.
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Abstract
Control of cell proliferation is essential to generate the defined form of a multi-cellular organism. While much is known about the regulators for cell cycle progression, relatively little is known about the state of growth arrest. Growth arrest (G0) is defined as a cell in a metabolically active but proliferation-quiescent state (reviewed in Baserga (1985) The Biology of Cell Reproduction), typically induced by serum starvation in vitro. Using subtractive hybridization, Schneider et al. (Cell 54 (1988) 787) identified six genes (Gas1 through Gas6) whose expressions are upregulated in serum-deprived NIH3T3 cells. Among the Gas genes, Gas1 is the only one that can cause growth arrest when expressed in cultured cell (Cell 70 (1995) 595; Int. J. Cancer 9 (1998) 569). Here, we describe for the first time the expression pattern of Gas1 during mouse embryogenesis. Our data reveal that Gas1 is expressed in many regions that the cells are actively proliferating and suggest that it may have other roles during development than negatively regulating cell proliferation. Furthermore, we have cloned the chick GAS1 gene and documented the similarity and divergence of Gas1 gene expression patterns between the two species.
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Affiliation(s)
- C S Lee
- Department of Embryology, Carnegie Institution of Washington, 115 West University Parkway, Baltimore, MD 21210, USA
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Fan CM, Rafferty EA, Geller SC, Kaufman JA, Brewster DC, Cambria RP, Waltman AC. Endovascular stent-graft in abdominal aortic aneurysms: the relationship between patent vessels that arise from the aneurysmal sac and early endoleak. Radiology 2001; 218:176-82. [PMID: 11152798 DOI: 10.1148/radiology.218.1.r01ja30176] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [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: 11/11/2022]
Abstract
PURPOSE To determine the association of patent sac branch vessels (lumbar and inferior mesenteric arteries [IMAs]) with early endoleak rate after stent-graft repair of abdominal aortic aneurysm (AAA). MATERIALS AND METHODS Pre- and postoperative computed tomographic (CT) angiograms in 158 patients who underwent stent-graft AAA repair were retrospectively reviewed to determine the preoperative patency of IMAs and other sac branch vessels (feeders) and presence or absence of immediate postoperative endoleak. Relationships of early endoleak rate with total branch vessel, IMA, and lumbar artery patency and graft type were evaluated. RESULTS There was a significant association between patency of sac feeders and rate of early endoleak, especially type 2. As total patent feeders increased from zero to three to four to six, total endoleak rate increased from 6% (one of 17) to 35% (30 of 86); type 2 endoleak rate, from 0% to 25%. IMA patency was significantly associated with total early endoleak rate. Increasing lumbar artery patency also was associated with significantly higher total and type 2 endoleak rates: With zero to three lumbar arteries, the total endoleak rate was 17% and type 2 endoleak rate was 13%, as compared with 60% and 50%, respectively, with more than six patent lumbar arteries. CONCLUSION Sac branch vessel patency is associated with significantly higher early total and type 2 endoleak rates after stent-graft repair of AAAs; thus, patent sac branches play an important role in the pathogenesis of endoleaks.
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Affiliation(s)
- C M Fan
- Division of Vascular Radiology, Massachusetts General Hospital, 55 Fruit St, Gray 290, Boston, MA 02114, USA.
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Kaufman JA, Geller SC, Brewster DC, Fan CM, Cambria RP, LaMuraglia GM, Gertler JP, Abbott WM, Waltman AC. Endovascular repair of abdominal aortic aneurysms: current status and future directions. AJR Am J Roentgenol 2000; 175:289-302. [PMID: 10915659 DOI: 10.2214/ajr.175.2.1750289] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- J A Kaufman
- Division of Vascular Radiology, Massachusetts General Hospital, Boston, MA 02114, USA
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Abstract
PURPOSE To review a 26-year single-center clinical experience with inferior vena caval filters. MATERIALS AND METHODS During 1973-1998, 1,765 filters were implanted in 1,731 patients. Hospital files were reviewed, and data were collected about the indications, safety, effectiveness, numbers, and types of caval filters. Fatal post-filter pulmonary embolism (PE) was considered the primary outcome. Morbidity and mortality were determined as secondary outcomes. Survival and morbidity-free survival curves were calculated. RESULTS The prevalence of observed post-filter PE was 5.6%. It was fatal in 3.7% of patients. In most patients, fatal PE occurred soon after filter insertion (median, 4.0 days; 95% CI: 2.2, 5.8 days). Major complications occurred in 0.3% of procedures. The prevalence of observed post-filter caval thrombosis was 2.7%. The 30-day mortality rate was 17.0% overall, higher among patients with neoplasms (19.5%) as compared with those without neoplasms (14.3%; P =.004). Filter efficacy and associated morbidity were not different in 46 patients with suprarenal filters. The rate of filters placed for prophylaxis was 4.7% overall and increased to 16.4% in 1998. From 1980 to 1996, there was a fivefold increase in the number of caval filter implants. In recent years, more filters were implanted in younger patients. CONCLUSION Inferior vena caval filters provide protection from life-threatening PE, with minimal morbidity.
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Affiliation(s)
- C A Athanasoulis
- Department of Radiology, GRB 290A, Massachusetts General Hospital, 32 Fruit St, Boston, MA 02114, USA.
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Rehring TF, Brewster DC, Cambria RP, Kaufman JA, Geller SC, Fan CM, Gertler JP, Lamuraglia GM, Abbott WM. Utility and reliability of endovascular aortouniiliac with femorofemoral crossover graft for aortoiliac aneurysmal disease. J Vasc Surg 2000; 31:1135-41. [PMID: 10842150 DOI: 10.1067/mva.2000.107120] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [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: 11/22/2022]
Abstract
OBJECTIVE The purpose of this study was to determine the early efficacy of endovascular aortouniiliac stent grafts with femorofemoral bypass graft in the treatment of aortoiliac aneurysmal disease. METHODS We analyzed 51 consecutive patients from January 1997 to March 1999 with a mean follow-up of 15.8 months. Patients ranged in age from 44 to 93 years (mean, 75 years) with a mean aortic aneurysm diameter of 6.2 cm. Technical success was achieved in 50 patients; one patient required conversion to open repair intraoperatively. We placed 28 custom-made and 22 commercial devices. The mean operative time was 223 minutes. The endograft was extended to the external iliac artery in 42% of cases. The contralateral common iliac artery was occluded using either a closed covered stent or intraluminal coils. RESULTS The median hospital stay was 4 days with an average intensive care unit stay of 0.25 days. There were no operative mortalities. Two patients died during follow-up from unrelated conditions. Endoleaks occurred in 11 patients (22%); seven patients (14%) required intervention (four catheter based, three operative). Other complications occurred in 38% of patients but were largely remote or wound related. One femorofemoral bypass graft occluded immediately postoperatively as a result of an intraprocedural external iliac dissection yielding a 98% primary patency and 100% secondary patency. Clinical success was achieved in 88% of patients. CONCLUSIONS These data suggest that this strategy represents a reliable method of repair of aortoiliac aneurysmal disease and extends the capability of an endoluminal approach to patients with complex iliac anatomy.
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Affiliation(s)
- T F Rehring
- Division of Vascular Surgery, Massachusetts General Hospital and Departments of Surgery and Radiology, Harvard Medical School, Boston, USA
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Lee CW, Kaufman JA, Fan CM, Geller SC, Brewster DC, Cambria RP, Lamuraglia GM, Gertler JP, Abbott WM, Waltman AC. Clinical outcome of internal iliac artery occlusions during endovascular treatment of aortoiliac aneurysmal diseases. J Vasc Interv Radiol 2000; 11:567-71. [PMID: 10834486 DOI: 10.1016/s1051-0443(07)61607-8] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To determine the clinical outcome of hypogastric artery occlusion in patients who underwent endovascular treatment of aortoiliac aneurysmal disease. MATERIAL AND METHODS From January 1994 to March 1998, 94 patients underwent endovascular treatment of aneurysmal diseases involving the infra-abdominal aorta or iliac arteries. Preoperative and intraoperative radiologic data were reviewed. Discharge summaries, clinic visits, and phone calls formed the basis for clinical follow-up, with a mean follow-up period of 7.3 months (range, 1-24 months). RESULTS Because of the anatomy of the aneurysms, 28 patients required occlusion of one or more hypogastric arteries. One of the 28 patients died of unrelated causes before follow-up. Seven (26%) of the remaining 27 patients developed symptoms attributable to the hypogastric artery occlusions. Five patients developed new buttock or thigh claudication; of these five patients, three with initially mild symptoms noted complete or near complete resolution of symptoms upon follow-up. One patient with originally significant claudication at 2-year follow-up noted near resolution of symptoms. The other patient with severe pain did not improve significantly on final 1-year follow-up before his death (of unrelated causes). Other clinical complications were worsening sexual function in one patient and a nonhealing sacral decubitus ulcer that developed in a debilitated patient in the postoperative setting, which required surgery. No bowel ischemia was observed. CONCLUSION When treating aortoiliac aneurysmal disease through an endovascular approach, the occlusion of internal iliac artery is often necessary but carries with it a small but finite chance of morbidity.
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Affiliation(s)
- C W Lee
- Division of Vascular and Interventional Radiology, Massachusetts General Hospital, Boston, USA
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Abstract
One major function of the hypothalamus is to maintain homeostasis by modulating the secretion of pituitary hormones. The paraventricular (PVN) and supraoptic (SON) nuclei are major integration centers for the output of the hypothalamus to the pituitary. The bHLH-PAS transcription factor SIM1 is crucial for the development of several neuroendocrine lineages within the PVN and SON. bHLH-PAS proteins require heterodimerization for their function. ARNT, ARNT2, and BMAL1 are the three known general heterodimerization partners for bHLH-PAS proteins. Here, we provide evidence that Sim1 and Arnt2 form dimers in vitro, that they are co-expressed in the PVN and SON, and that their loss of function affects the development of the same sets of neuroendocrine cell types within the PVN and SON. Together, these results implicate ARNT2 as the in vivo dimerization partner of SIM1 in controlling the development of these neuroendocrine lineages.
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Affiliation(s)
- J L Michaud
- Service de Génétique Médicale, Hôpital Sainte-Justine, Montréal, Canada
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Lee CS, Buttitta LA, May NR, Kispert A, Fan CM. SHH-N upregulates Sfrp2 to mediate its competitive interaction with WNT1 and WNT4 in the somitic mesoderm. Development 2000; 127:109-18. [PMID: 10654605 DOI: 10.1242/dev.127.1.109] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Dorsoventral polarity of the somitic mesoderm is established by competitive signals originating from adjacent tissues. The ventrally located notochord provides the ventralizing signals to specify the sclerotome, while the dorsally located surface ectoderm and dorsal neural tube provide the dorsalizing signals to specify the dermomyotome. Noggin and SHH-N have been implicated as the ventralizing signals produced by the notochord. Members of the WNT family of proteins, on the other hand, have been implicated as the dorsalizing signals derived from the ectoderm and dorsal neural tube. When presomitic explants are confronted with cells secreting SHH-N and WNT1 simultaneously, competition to specify the sclerotome and dermomyotome domains within the naive mesoderm can be observed. Here, using these explant cultures, we provide evidence that SHH-N competes with WNT1, not only by upregulating its own receptor Ptc1, but also by upregulating Sfrp2 (Secreted frizzled-related protein 2), which encodes a potential WNT antagonist. Among the four known Sfrps, Sfrp2 is the only member expressed in the sclerotome and upregulated by SHH-N recombinant protein. We further show that SFRP2-expressing cells can reduce the dermomyotome-inducing activity of WNT1 and WNT4, but not that of WNT3a. Together, our results support the model that SHH-N at least in part employs SFRP2 to reduce WNT1/4 activity in the somitic mesoderm.
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Affiliation(s)
- C S Lee
- Department of Embryology, Carnegie Institution of Washington, Baltimore, MD 21210, USA
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Abstract
Strange fits of passion I have knownellipsis (W Wordsworth, 'Strange fits of passion'.) bHLH-PAS proteins are regulators of developmental and physiological events that are well conserved between vertebrates and invertebrates. Recent studies using mouse knockouts of bHLH-PAS genes have provided novel insight into the roles of hypoxia inducible factors in controlling oxygen-regulated development and homeostasis, and the role of Single-minded-1 in regulating development and transcription in the hypothalamus. The Drosophila spineless and vertebrate Aryl hydrocarbon receptor bHLH-PAS orthologs both function in chemosensory processes, but in fundamentally different ways. Spineless controls antennal, limb, and sensory cell development, whereas the Aryl hydrocarbon receptor regulates the response to toxin metabolism. Structural analyses of the PAS domain provide insight into how this interaction domain can act as ligand-binding environmental sensor and signal transducer.
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Affiliation(s)
- S T Crews
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill Chapel Hill, North Carolina, 27599-7260, USA.
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Kaufman JA, Brewster DC, Geller SC, Fan CM, Cambria RP, Abbott WA, Waltman AC. Custom bifurcated stent-graft for abdominal aortic aneurysms: initial experience. J Vasc Interv Radiol 1999; 10:1099-106. [PMID: 10496714 DOI: 10.1016/s1051-0443(99)70198-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [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: 11/24/2022] Open
Abstract
PURPOSE To describe a custom bifurcated stent-graft for possible treatment of abdominal aortic aneurysm (AAA). MATERIALS AND METHODS Five male patients (mean age, 76 +/- 6 years), who had AAA (mean diameter, 4.7 +/- 0.4 cm) and who were considered to be at high risk for conventional surgery, were treated with a custom modular bifurcated stent-graft constructed with bifurcated 24-mm x 12-mm (upper body diameter x iliac limb diameter) Cooley Veri-Soft Woven polyester grafts and Gianturco-Rösch Z stents. The stent-graft body was delivered through 20-22-F sheaths, and the contralateral iliac limb was delivered through a 16-F sheath by means of surgical exposure of the common femoral arteries. A flared distal limb extender (12 mm to 14 mm) was created for one patient to accommodate a large common iliac artery. RESULTS Stent-grafts were successfully deployed without complications in all five patients. There were no proximal or distal leaks. A lumbar-to-inferior mesenteric artery leak was seen in one patient at 24 hours. At 6-month follow-up, all devices were intact, with complete exclusion and shrinkage of the aneurysm in four of five patients. Aneurysm size remained stable in the one patient with a lumbar-to-inferior mesenteric artery leak. CONCLUSION A custom, bifurcated stent-graft was utilized for endovascular treatment of AAA. Long-term follow-up is necessary for the device.
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Affiliation(s)
- J A Kaufman
- Department of Radiology, Massachusetts General Hospital, Boston 02114, USA
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24
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Abstract
In this paper, we present an algorithm to simultaneously estimate multiple-frame motions and filter image sequences. The relative motion dk(x) between the reference frame s(x) and the kth frame s(x-dk(x)) in the presence of additive white Gaussian noise (AWGN) is estimated using the maximum-likelihood (ML) principle. The reference frame is also filtered in the linear minimum mean square error (LMMSE) sense during the process of motion estimation. Simulation experiments are performed using the affine motion model to illustrate the performance of this method.
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Affiliation(s)
- C M Fan
- U.S. Patent and Trademark Office, Crystal City, VA 22202, USA
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Michaud JL, Rosenquist T, May NR, Fan CM. Development of neuroendocrine lineages requires the bHLH-PAS transcription factor SIM1. Genes Dev 1998; 12:3264-75. [PMID: 9784500 PMCID: PMC317216 DOI: 10.1101/gad.12.20.3264] [Citation(s) in RCA: 283] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/1998] [Accepted: 08/21/1998] [Indexed: 11/25/2022]
Abstract
The bHLH-PAS transcription factor SIM1 is expressed during the development of the hypothalamic-pituitary axis in three hypothalamic nuclei: the paraventricular nucleus (PVN), the anterior periventricular nucleus (aPV), and the supraoptic nucleus (SON). To investigate Sim1 function in the hypothalamus, we produced mice carrying a null allele of Sim1 by gene targeting. Homozygous mutant mice die shortly after birth. Histological analysis shows that the PVN and the SON of these mice are hypocellular. At least five distinct types of secretory neurons, identified by the expression of oxytocin, vasopressin, thyrotropin-releasing hormone, corticotropin-releasing hormone, and somatostatin, are absent in the mutant PVN, aPV, and SON. Moreover, we show that SIM1 controls the development of these secretory neurons at the final stages of their differentiation. A subset of these neuronal lineages in the PVN/SON are also missing in mice bearing a mutation in the POU transcription factor BRN2. We provide evidence that, during development of the Sim1 mutant hypothalamus, the prospective PVN/SON region fails to express Brn2. Our results strongly indicate that SIM1 functions upstream to maintain Brn2 expression, which in turn directs the terminal differentiation of specific neuroendocrine lineages within the PVN/SON.
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Affiliation(s)
- J L Michaud
- Department of Embryology, Carnegie Institution of Washington, Baltimore, Maryland 21210 USA
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McMahon JA, Takada S, Zimmerman LB, Fan CM, Harland RM, McMahon AP. Noggin-mediated antagonism of BMP signaling is required for growth and patterning of the neural tube and somite. Genes Dev 1998; 12:1438-52. [PMID: 9585504 PMCID: PMC316831 DOI: 10.1101/gad.12.10.1438] [Citation(s) in RCA: 619] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/1997] [Accepted: 03/16/1998] [Indexed: 02/07/2023]
Abstract
Embryonic patterning in vertebrates is dependent upon the balance of inductive signals and their specific antagonists. We show that Noggin, which encodes a bone morphogenetic protein (BMP) antagonist expressed in the node, notochord, and dorsal somite, is required for normal mouse development. Although Noggin has been implicated in neural induction, examination of null mutants in the mouse indicates that Noggin is not essential for this process. However, Noggin is required for subsequent growth and patterning of the neural tube. Early BMP-dependent dorsal cell fates, the roof plate and neural crest, form in the absence of Noggin. However, there is a progressive loss of early, Sonic hedgehog (Shh)-dependent ventral cell fates despite the normal expression of Shh in the notochord. Further, somite differentiation is deficient in both muscle and sclerotomal precursors. Addition of BMP2 or BMP4 to paraxial mesoderm explants blocks Shh-mediated induction of Pax-1, a sclerotomal marker, whereas addition of Noggin is sufficient to induce Pax-1. Noggin and Shh induce Pax-1 synergistically. Use of protein kinase A stimulators blocks Shh-mediated induction of Pax-1, but not induction by Noggin, suggesting that induction is mediated by different pathways. Together these data demonstrate that inhibition of BMP signaling by axially secreted Noggin is an important requirement for normal patterning of the vertebrate neural tube and somite.
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Affiliation(s)
- J A McMahon
- Department of Molecular and Cellular Biology, The Biolabs, Harvard University, Cambridge, Massachusetts 02138, USA.amcmahon.biosun.harvar d.edu
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Kaufman JA, Fan CM, Geller SC, Rieumont MJ, Waltman AC. Percutaneous revision of excess length from an implanted long-term central venous access device. AJR Am J Roentgenol 1997; 169:1732-4. [PMID: 9393199 DOI: 10.2214/ajr.169.6.9393199] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- J A Kaufman
- Division of Vascular Radiology, Harvard Medical School, Massachusetts General Hospital, Boston 02114, USA
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28
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Abstract
Dorsoventral patterning of somites into sclerotome and dermomyotome involves antagonistic actions of ventralizing and dorsalizing signals originating from tissues surrounding the somites. The notochord and the floor plate of the neural tube provide a ventralizing signal(s) directing sclerotome development, whereas the surface ectoderm and dorsal neural tube provide a dorsalizing signal(s) directing dermomyotome development. Evidence has been provided that Sonic Hedgehog mediates the ventralizing effects of notochord and floor plate, but the dorsalizing signal(s) that patterns the dermomyotome has not been identified. The documented expression of Wnt1 and Wnt3a in the dorsal neural tube and of Wnt4 and Wnt6 in the surface ectoderm at the time of dermomyotome specification prompted us to investigate the involvement of WNT proteins in patterning the dermomyotome. Here we show that tissue culture cells expressing these WNT family members can maintain and induce dermomyotome marker expression in presomitic mesoderm explants, supporting the hypothesis that WNT proteins mediate the dorsalizing effects of the surface ectoderm and dorsal neural tube on somites.
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Affiliation(s)
- C M Fan
- Department of Embryology, Carnegie Institution of Washington, 115 West University Parkway, Baltimore, Maryland 21210, USA.
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Boiselle PM, Shepard JA, Mark EJ, Szyfelbein WM, Fan CM, Slanetz PJ, Trotman-Dickenson B, Halpern EF, Miller SW, McLoud TC. Routine addition of an automated biopsy device to fine-needle aspiration of the lung: a prospective assessment. AJR Am J Roentgenol 1997; 169:661-6. [PMID: 9275873 DOI: 10.2214/ajr.169.3.9275873] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.9] [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: 02/05/2023]
Abstract
OBJECTIVE The purpose of this study was to prospectively assess the usefulness of the routine addition of an automated biopsy device (ABD) to fine-needle aspiration (FNA) of the lung and to examine the complication rate of this procedure. SUBJECTS AND METHODS Fifty biopsies were performed under CT guidance using a coaxial technique with a 19-gauge introducer needle and a 22-gauge aspirating needle followed by a 20-gauge ABD. An average of 3.5 FNA specimens and 2.5 core specimens were obtained. Cytology and histology specimens were interpreted separately by two experienced pathologists who were unaware of the other's interpretation. Final diagnoses were based on surgery, microbiology, definitive biopsy diagnosis, and clinical follow-up. All complications were recorded. RESULTS Of 34 malignant lesions, we achieved a diagnostic accuracy of 94% for FNA and 59% for core biopsy (p < .01). Combined accuracy was 94%. Of 16 benign lesions, an accurate definitive diagnosis was made in 31% of cases using FNA and in 69% of cases using core biopsy (p = .08). Combined accuracy was 69%. In the subset of benign lesions that were not acute infections (n = 8), an accurate definitive benign diagnosis was made in 12% of cases using FNA and in 75% of cases using core biopsy (p < .05). No false-positive diagnoses of malignancy occurred. Complications included pneumothorax, nine (18%) of 50 cases; chest tube, one (2%) of 50 cases minor pulmonary hemorrhage, seven (14%) of 50 cases; and minor hemoptysis, two (4%) of 50 cases. CONCLUSION The complication rates of FNA with the addition of an ABD are similar to those reported in the literature for FNA alone. The addition of an ABD significantly increases the diagnostic accuracy only for the subset of benign lesions that are not acute infections.
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Affiliation(s)
- P M Boiselle
- Department of Radiology, Massachusetts General Hospital, Boston 02114, USA
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30
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Affiliation(s)
- J Michaud
- Department of Embryology, Carnegie Institution of Washington, Baltimore, Maryland 21210, USA
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31
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Probst MR, Fan CM, Tessier-Lavigne M, Hankinson O. Two murine homologs of the Drosophila single-minded protein that interact with the mouse aryl hydrocarbon receptor nuclear translocator protein. J Biol Chem 1997; 272:4451-7. [PMID: 9020169 DOI: 10.1074/jbc.272.7.4451] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.6] [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
Drosophila single-minded, which acts as a positive master gene regulator in central nervous system midline formation in Drosophila, its two mouse homologs SIM1 and SIM2, and the mammalian aryl hydrocarbon receptor (AHR) and aryl hydrocarbon receptor nuclear translocator (ARNT) proteins are members of the basic-helix-loop-helix.PAS family of transcription factors. In the yeast two-hybrid system, we demonstrate strong constitutive interaction of ARNT with SIM1 and SIM2 and fully ligand-dependent interaction of ARNT with AHR. Both the helix-loop-helix and the PAS regions of SIM1 and of ARNT are required for efficient heterodimerization. SIM1 and SIM2 do not form homodimers, and they do not interact with AHR. We also failed to detect homodimerization of ARNT. The interaction of ARNT with SIM1 was confirmed with in vitro synthesized proteins. Like AHR, in vitro synthesized SIM1 associates with the 90-kDa heat shock protein. SIM1 inhibits binding of the AHR.ARNT dimer to the xenobiotic response element in vitro. Introduction of SIM1 into hepatoma cells inhibits transcriptional transactivation by the endogenous AHR.ARNT dimer. The mouse SIM1. ARNT dimer binds only weakly to a proposed DNA target for the Drosophila SIM.ARNT dimer. In adult mice mRNA for SIM1 was expressed in lung, skeletal muscle, and kidney, whereas the mRNA for SIM2 was found in the latter two. ARNT is also expressed in these organs. Thus mouse SIM1 and SIM2 are novel heterodimerization partners for ARNT in vitro, and they may function both as positive and negative transcriptional regulators in vivo, during embryogenesis and in the adult organism.
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Affiliation(s)
- M R Probst
- Jonsson Comprehensive Cancer Center, School of Medicine, UCLA, Los Angeles, California 90095, USA
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32
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Fidias P, Fan CM, McGovern FJ, Wright CD, Kaufman J, Grossbard ML. Intracaval extension of germ cell carcinoma: diagnosis via endovascular biopsy and a review of the literature. Eur Urol 1997; 31:376-9. [PMID: 9129935 DOI: 10.1159/000474487] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [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: 02/04/2023]
Abstract
We report a case of testicular carcinoma invading the inferior vena cava. Tumor invasion was diagnosed via endovascular biopsy. This is the first known report of a diagnosis of this entity using endovascular biopsy. We also review the literature on diagnosis and management of inferior vena caval involvement by testicular cancer.
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Affiliation(s)
- P Fidias
- Hematology-Oncology Unit, Massachusetts General Hospital, Boston 02114, USA
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33
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Abstract
The Wnt-1 gene is required for the development of midbrain and cerebellum; previous work showed that knockout of Wnt-1 causes the loss of most molecular markers of these structures in early embryos and deletion of these structures by birth. However, neither the extent of early neuronal defects nor any possible alterations in structures adjacent to presumptive midbrain and cerebellum were examined. By using a neuron-specific antibody and fluorescent axon tracers, we show that central and peripheral neuronal development are altered in mutants during initial axonogenesis on embryonic day 9.5. The absence of neuronal landmarks, including oculomotor and trochlear nerves and cerebellar plate, suggests that both mesencephalon and rhombomere 1 (r1) are delected, with the remaining neural tube fused to form a new border between the caudalmost portion of the prosencephalon (prosomere 1, or p1) and r2. Central axons accurately traverse this novel border by forming normal longitudinal tracts into the rhombencephalon, implying that the cues that direct these axons are aligned across neuromeres and are not affected by the delection. The presence of intact p1 and r2 is further supported by the retention of markers for these two neuromers, including a marker of p1, the Sim-2 gene, and an r2-specific lacZ transgene in mutant embryos. In addition, alterations in the Sim-2 expression domain in ventral prosencephalon, rostral to p1, provide novel evidence for Wnt-1 function in this region.
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Affiliation(s)
- G S Mastick
- Department of Biology, University of Michigan, Ann Arbor 48109,USA.
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Ray CE, Rivitz SM, Fan CM, Geller SC. Re: complication of pulmonary arteriography: contrast extravasation from a wedged pigtail-shaped catheter. Cardiovasc Intervent Radiol 1996; 19:305-6. [PMID: 8755092 DOI: 10.1007/bf02577658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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35
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Fan CM, Kuwana E, Bulfone A, Fletcher CF, Copeland NG, Jenkins NA, Crews S, Martinez S, Puelles L, Rubenstein LR, Tessier-Lavigne M. "Expression patterns of two murine homologs of Drosophila single-minded suggest possible roles in embryonic patterning and in the pathogenesis of Down syndrome.". Mol Cell Neurosci 1996; 7:519. [PMID: 8875433 DOI: 10.1006/mcne.1996.0037] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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36
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Fan CM, Whitman GJ, Chew FS. Radiologic-Pathologic Conferences of the Massachusetts General Hospital. Necrotizing fasciitis of the scrotum (Fournier's gangrene). AJR Am J Roentgenol 1996; 166:1164. [PMID: 8615262 DOI: 10.2214/ajr.166.5.8615262] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- C M Fan
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
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37
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Pourquié O, Fan CM, Coltey M, Hirsinger E, Watanabe Y, Bréant C, Francis-West P, Brickell P, Tessier-Lavigne M, Le Douarin NM. Lateral and axial signals involved in avian somite patterning: a role for BMP4. Cell 1996; 84:461-71. [PMID: 8608600 DOI: 10.1016/s0092-8674(00)81291-x] [Citation(s) in RCA: 319] [Impact Index Per Article: 11.4] [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: 01/31/2023]
Abstract
In vertebrates, muscles of the limbs and body wall derive from the lateral compartment of the embryonic somites, and axial muscles derive from the medial compartment. Whereas the mechanisms that direct patterning of somites along the dorsoventral axis are beginning to be understood, little is known about the tissue interactions and signaling molecules that direct somite patterning along the mediolateral axis. We report the identification of a specific marker for the lateral somitic compartment and its early derivatives, cSim1, an avian homolog of the Drosophila single minded gene. Using this marker, we provide evidence that specification of the lateral somitic lineage results from the antagonistic actions of a diffusible medializing signal from the neural tube and a diffusible lateralizing signal from the lateral plate mesoderm, and we implicate bone morphogenetic protein 4(BMP4) in directing this lateralization.
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Affiliation(s)
- O Pourquié
- Institut d'Embryologie du Centre National de la Recherche Scientifique et du Collège de France, Nogent sur Marne
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38
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Fan CM, Kuwana E, Bulfone A, Fletcher CF, Copeland NG, Jenkins NA, Crews S, Martinez S, Puelles L, Rubenstein JL, Tessier-Lavigne M. Expression patterns of two murine homologs of Drosophila single-minded suggest possible roles in embryonic patterning and in the pathogenesis of Down syndrome. Mol Cell Neurosci 1996; 7:1-16. [PMID: 8812055 DOI: 10.1006/mcne.1996.0001] [Citation(s) in RCA: 152] [Impact Index Per Article: 5.4] [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: 02/02/2023] Open
Abstract
The single-minded (sim) gene encodes a transcriptional regulator that functions as a key determinant of central nervous system (CNS) midline development in Drosophila. We report here the identification of two murine homologs of sim, Sim1 and Sim2, whose products show a high degree of sequence conservation with Drosophila SIM in their amino-terminal halves, with each containing a basic helix-loop-helix domain as well as a PAS domain. Sim1 maps to the proximal region of mouse chromosome 10, whereas Sim2 maps to a portion of the distal end of chromosome 16 that is syntenic to the Down syndrome critical region of human chromosome 21. Recent exon-trapping studies have identified in the critical region several exons of a human sim homolog which appears to be the homolog of murine Sim2; this has led to the hypothesis that increased dosage of this sim homolog in cases of trisomy 21 might be a causal factor in the pathogenesis of Down syndrome. We have examined the expression patterns of the Sim genes during embryogenesis. Both genes are expressed in dynamic and selective fashion in specific neuromeric compartments of the developing forebrain, and the expression pattern of Sim2 provides evidence for early regionalization of the diencephalon prior to any overt morphological differentiation in this region. Outside the CNS, Sim1 is expressed in mesodermal and endodermal tissues, including developing somites, mesonephric duct, and foregut. Sim2 is expressed in facial and trunk cartilage, as well as trunk muscles. Both murine Sim genes are also expressed in the developing kidney. Our data suggest that the Sim genes play roles in directing the regionalization of tissues where they are expressed. Moreover, the expression pattern documented for Sim2 may provide insights into its potential roles in Down syndrome.
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Affiliation(s)
- C M Fan
- Department of Anatomy, University of California, San Francisco 94143-0452, USA
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39
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Muenke M, Bone LJ, Mitchell HF, Hart I, Walton K, Hall-Johnson K, Ippel EF, Dietz-Band J, Kvaløy K, Fan CM. Physical mapping of the holoprosencephaly critical region in 21q22.3, exclusion of SIM2 as a candidate gene for holoprosencephaly, and mapping of SIM2 to a region of chromosome 21 important for Down syndrome. Am J Hum Genet 1995; 57:1074-9. [PMID: 7485157 PMCID: PMC1801356] [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: 01/25/2023] Open
Abstract
We set out to define the holoprosencephaly (HPE) critical region on chromosome 21 and also to determine whether there were human homologues of the Drosophila single-minded (sim) gene that might be involved in HPE. Analysis of somatic cell hybrid clones that contained rearranged chromosomes 21 from HPE patients defined the HPE minimal critical region in 21q22.3 as D21S113 to qter. We used established somatic cell hybrid mapping panels to map SIM2 to chromosome 21 within subbands q22.2-q22.3. Analysis of the HPE patient-derived somatic cell hybrids showed that SIM2 is not deleted in two of three patients and thus is not a likely candidate for HPE1, the HPE gene on chromosome 21. However, SIM2 does map within the Down syndrome critical region and thus is a candidate gene that might contribute to the Down syndrome phenotype.
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Affiliation(s)
- M Muenke
- Children's Hospital of Philadelphia, PA 19104-4399, USA
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40
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Affiliation(s)
- C M Fan
- Department of Radiology, Massachusetts General Hospital, Boston 02114, USA
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41
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Fan CM, Porter JA, Chiang C, Chang DT, Beachy PA, Tessier-Lavigne M. Long-range sclerotome induction by sonic hedgehog: direct role of the amino-terminal cleavage product and modulation by the cyclic AMP signaling pathway. Cell 1995; 81:457-65. [PMID: 7736597 DOI: 10.1016/0092-8674(95)90398-4] [Citation(s) in RCA: 278] [Impact Index Per Article: 9.6] [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: 01/26/2023]
Abstract
A long-range signal encoded by the Sonic hedgehog (Shh) gene has been implicated as the ventral patterning influence from the notochord that induces sclerotome and represses dermomyotome in somite differentiation. Long-range effects of hedgehog (hh) signaling have been suggested to result either from local induction of a secondary diffusible signal or from the direct action of the highly diffusible carboxy-terminal product of HH autoproteolytic cleavage. Here we provide evidence that the long-range somite patterning effects of SHH are instead mediated by a direct action of the amino-terminal cleavage product. We also show that pharmacological manipulations to increase the activity of cyclic AMP-dependent protein kinase A can selectively antagonize the effects of the amino-terminal cleavage product. Our results support the operation of a single evolutionarily conserved signaling pathway for both local and direct long-range inductive actions of HH family members.
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Affiliation(s)
- C M Fan
- Howard Hughes Medical Institute, Department of Anatomy, University of California, San Francisco 94143-0452, USA
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42
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Luo WY, Ying Y, Li ZX, Fan CM, Zhou JH, Fang XC. [Pharmacokinetics of contragestazol (DL-111-IT), a new non-steroid antifertility agent in monkeys]. Yao Xue Xue Bao 1995; 30:408-411. [PMID: 7572179] [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: 05/21/2023]
Abstract
The pharmacokinetics of contragestazol, an early pregnancy temperating agent [3-(2-ethylphenyl)-5-(3-methoxyphenyl)-1H-1,2,4-triazole, DL-111-IT] was studied in Rhesus monkey. The blood concentration of DL-111-IT was determined by coupled column system HPLC method. Using an aqueous vehicle (20% cremophor EL in saline) DL-111-IT was injected intravenously to monkeys at doses of 25, 12.5 and 6.3 mg.kg-1. Blood drug concentration were measured. Using a programmable calculator the calculated pharmacokinetic parameters were as follows: alpha 1.83 h-1, 4.71 h-1 and 3.61 h-1, beta 0.15 h-1, 0.08 h-1 and 0.09 h-1; T1/2 beta 6.63 h, 10.2 h and 10.1 h; AUC 9.54 micrograms.h-1.ml-1, 3.94 micrograms.h-1.ml-1 and 3.75 micrograms.h-1.ml-1. An oil solution of DL-111-IT was injected intramuscularly in monkeys at doses of 50, 25 and 12.5 mg.kg-1. Its blood concentrations were determined at 0.08, 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 8, 12 and 24 h after administration. From the time vs concentration curve, the pharmacokinetic parameters obtained were as follows: Ka 0.98 h-1, 1.03 h-1 and 1.45 h-1; Ke 0.42 h-1, 0.37 h-1 and 0.60 h-1; T1/2Ke 1.66 h, 1.90 h and 1.16 h; T (peak) 1.52 h, 1.57 h and 1.09 h; AUC 4.86 micrograms.h-1.ml-1, 5.61 micrograms.h-1.ml-1 and 1.74 micrograms.h-1.ml-1.
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Affiliation(s)
- W Y Luo
- Zhejiang Medical University, Hangzhou
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43
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Abstract
An early step in the development of vertebrae, ribs, muscle, and dermis is the differentiation of the somitic mesoderm into dermomyotome dorsally and sclerotome ventrally. To analyze this process, we have developed an in vitro assay for somitic mesoderm differentiation. We show that sclerotomal markers can be induced by a diffusible factor secreted by notochord and floor plate and that heterologous cells expressing Sonic hedgehog (shh/vhh-1) mimic this effect. In contrast, expression of dermomyotomal markers can be caused by a contact-dependent signal from surface ectoderm and a diffusible signal from dorsal neural tube. Our results extend previous studies by suggesting that dorsoventral patterning of somites involves the coordinate action of multiple dorsalizing and ventralizing signals and that a diffusible form of Shh/Vhh-1 mediates sclerotome induction.
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Affiliation(s)
- C M Fan
- Howard Hughes Medical Institute, Department of Anatomy, University of California, San Francisco 94143-0452
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44
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Abstract
This correspondence presents a new pixel-recursive algorithm for estimating the nonuniform image motion from noisy measurements. The proposed method is performed in two steps. First, the pixels are examined to identify the (detectable) moving pixels, using a binary hypothesis testing. Then, characterizing the motion of the identified moving pixels in terms of a unitary transformation, the motion coefficients are estimated using a Kalman filter. Because the motion vector is typically (spatially) slowly varying, the size of the motion coefficient vector is significantly reduced. Consequently, the proposed Kalman filter need only search for the truncated coefficients of the motion field. The proposed method is simulated on a computer, and results are compared with the algorithm reported by Netravali and Robbins (see Bell Syst. Tech. J. vol.58, no.3, p.631-70, Mar. 1979).
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Affiliation(s)
- N M Namazi
- Dept. of Electr. Eng., Catholic Univ. of America, Washington, DC
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Fan CM. [Doppler echocardiographic assessment of prosthetic heart valve function]. Zhonghua Wai Ke Za Zhi 1993; 31:630-2. [PMID: 8033679] [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: 01/28/2023]
Abstract
The normal hemodynamic parameters of 90 patients with St. Jude bileaflet valve, Medtronic-Hall, Sorin and GK tilting disc valves were investigated and compared to those of 30 control subjects by transthoracic Doppler echocardiographic technique. The results showed that although the mitral prosthetic valve area increased significantly and the peak velocity and the peak pressure gradient decreased significantly after mitral valve replacement, the effective orifice area (EOA), peak velocity (Vmax), and peak gradient (PG) in 4 different prosthetic valve groups still had significant differences from those of the normal native valve group. Among the 4 types of prosthetic valves St. Jude bileaflet valve had the largest EOA (3.12 +/- 0.47 cm2) and the lowest peak pressure gradients (9.3 +/- 1.1 mmHg). The EOA of the other 3 types of tilting disc valves showed no significant difference. The possibility of determining the indication of mitral valve replacement by Doppler echocardiography was also discussed.
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Affiliation(s)
- C M Fan
- Fuwai Hospital, Chinese Academy of Medical Sciences, Beijing
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Fan CM, Tao SQ, Liu HY, Hu BL, Yang HY, Zhu XD. Hemodynamic evaluation of bovine pericardial xenograft valves in the mitral position by stress Doppler echocardiography. Chin Med J (Engl) 1993; 106:40-4. [PMID: 8504681] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The function of a bovine pericardial xenograft valve in the mitral position was studied in 18 patients by using stress Doppler echocardiography after submaximal supine exercise. In 10 patients with normally functioning tissue valve, peak and mean gradients increased from 9.3 +/- 1.3 and 2.7 +/- 0.7 mmHg, respectively at rest, to 14.7 +/- 0.9 and 4.1 +/- 1.0 mmHg at peak exercise. The tissue valve area assessed by the Doppler pressure half-time method increased from 2.69 +/- 0.38 cm2 at rest, to 3.15 +/- 0.38 cm2 at peak exercise (P < 0.05). In 6 patients with mitral regurgitation, peak and mean gradients increased from 17.3 +/- 5.3 and 7.0 +/- 1.8 mmHg, respectively at rest, to 24.3 +/- 5.0 and 9.0 +/- 2.6 mmHg at peak exercise, but there was no significant change in valve area at peak exercise. Patients with severe isolated mitral regurgitation had a Vmax of more than 2 m/s and elevated pressure gradients at peak exercise. But the pressure half-time was relatively unaffected, allowing their differentiation from patients with tissue valvular stenosis. Stress Doppler echocardiography is a simple, noninvasive and reliable method for the evaluation of the mitral tissue valve function which is recommendable for patients with suspected mitral tissue valve dysfunction.
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Affiliation(s)
- C M Fan
- Cardiovascular Institute, Chinese Academy of Medical Sciences, Beijing
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47
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Huang YZ, Fan CM, Yang HY. [The advances in the research on the intravascular and intracardiac ultrasound imaging techniques]. Zhonghua Xin Xue Guan Bing Za Zhi 1992; 20:385-7. [PMID: 1307982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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48
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Fan CM. [Hemodynamic evaluation of GK and Medtronic-Hall prosthetic mitral valves by exercise Doppler echocardiography]. Zhonghua Xin Xue Guan Bing Za Zhi 1992; 20:335-7, 388. [PMID: 1307966] [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: 12/26/2022]
Abstract
Hemodynamic alterations were studied in 42 patients with GK and Medtronic-Hall (M-H) prosthetic valves by stress Doppler echocardiography after submaximal supine exercise. In the GK group, peak and mean gradients increased from 10.1 +/- 1.7 and 3.4 +/- 1.3 mmHg respectively, at rest to 15.3 +/- 3.1 and 5.4 +/- 1.5 mmHg at peak exercise (mean +/- s), mitral valve area increased from 2.61 +/- 0.34 cm2 at rest to 2.86 +/- 0.45 cm2 at peak exercise (P < 0.05). In the M-H group, peak and mean gradients increased from 11.3 +/- 1.8 and 4.3 +/- 1.0 mmHg respectively, at rest to 15.0 +/- 1.9 and 5.8 +/- 1.5 mmHg at peak exercise. Mitral valve area increased from 2.66 +/- 0.43 cm2 at rest to 2.94 +/- 0.38 cm2 at peak exercise (P < 0.05). The results showed that peak and mean gradients at rest in patients with GK prosthetic valve were lower than those of M-H group. But after exercise, the two prosthetic valves showed similar characteristics in hemodynamics. Exercise Doppler echocardiography is a simple, noninvasive and reliable method for the evaluation of the function of mechanical mitral prostheses.
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Affiliation(s)
- C M Fan
- Cardiovascular Institute, Chinese Academy of Medical Sciences, Beijing
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Abstract
The transcription factor NF-kappa B is a heterodimer consisting of two proteins encoded by different members of the rel gene family (p50 and p65). The p50 subunit is unusual among DNA-binding proteins in that its functional form is encoded in an open reading frame of relative molecular mass 105,000 (p105; ref. 4). The N-terminal region of this open reading frame encodes p50, whereas the remaining C terminus contains ankyrin repeats. Although p50 binds to DNA, full-length p105 translated in vitro does not. The mechanism by which p50 is generated in vivo, and the fate of the C-terminal region of p105 have not been established. Here we show that functional p50 is produced by ATP-dependent proteolysis of p105. Moreover, we find that the C-terminal half of p105 is not required for processing in vivo, and is rapidly degraded on processing. We propose that the C-terminal region of p105 is involved in the cytoplasmic assembly of the complex between the p50/p65 heterodimer and the inhibitor I kappa B.
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Affiliation(s)
- C M Fan
- Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138
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Abstract
We have isolated a full-length cDNA clone encoding a protein (PRDII-BF1) that binds specifically to a positive regulatory domain (PRDII) of the human IFN-beta gene promoter, and to a similar sequence present in a number of other promoters and enhancers. The sequence of this protein reveals two novel structural features. First, it is the largest sequence-specific DNA-binding protein reported to date (298 kD). Second, it contains two widely separated sets of C2-H2-type zinc fingers. Remarkably, each set of zinc fingers binds to the same DNA sequence motif with similar affinities and methylation interference patterns. Thus, this protein may act by binding simultaneously to reiterated copies of the same recognition sequence. Although the function of PRDII-BF1 is not known, the level of its mRNA is inducible by serum and virus, albeit with different kinetics.
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Affiliation(s)
- C M Fan
- Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138
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