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Greenberg SB, Ocampo AA, Xue Z, Chang NC, Thakkar KP, Reddy SB, Lee CJ, Ketchem CJ, Redd WD, Eluri S, Reed CC, Dellon ES. Increasing Rates of Esophageal Stricture and Dilation Over 2 Decades in Eosinophilic Esophagitis. Gastro Hep Adv 2022; 2:521-523. [PMID: 37293573 PMCID: PMC10249492 DOI: 10.1016/j.gastha.2022.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- S B Greenberg
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - A A Ocampo
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Z Xue
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - N C Chang
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - K P Thakkar
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - S B Reddy
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - C J Lee
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - C J Ketchem
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - W D Redd
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - S Eluri
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - C C Reed
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - E S Dellon
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Division of Gastroenterology and Hepatology, Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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Dell'Agnello G, Desai U, Kirson NY, Wen J, Meiselbach MK, Reed CC, Belger M, Lenox-Smith A, Martinez C, Rasmussen J. Reliability of coded data to identify earliest indications of cognitive decline, cognitive evaluation and Alzheimer's disease diagnosis: a pilot study in England. BMJ Open 2018; 8:e019684. [PMID: 29567847 PMCID: PMC5875601 DOI: 10.1136/bmjopen-2017-019684] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 01/22/2018] [Accepted: 02/01/2018] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVES Evaluate the reliability of using diagnosis codes and prescription data to identify the timing of symptomatic onset, cognitive assessment and diagnosis of Alzheimer's disease (AD) among patients diagnosed with AD. METHODS This was a retrospective cohort study using the UK Clinical Practice Research Datalink (CPRD). The study cohort consisted of a random sample of 50 patients with first AD diagnosis in 2010-2013. Additionally, patients were required to have a valid text-field code and a hospital episode or a referral in the 3 years before the first AD diagnosis. The earliest indications of cognitive impairment, cognitive assessment and AD diagnosis were identified using two approaches: (1) using an algorithm based on diagnostic codes and prescription drug information and (2) using information compiled from manual review of both text-based and coded data. The reliability of the code-based algorithm for identifying the earliest dates of the three measures described earlier was evaluated relative to the comprehensive second approach. Additionally, common cognitive assessments (with and without results) were described for both approaches. RESULTS The two approaches identified the same first dates of cognitive symptoms in 33 (66%) of the 50 patients, first cognitive assessment in 29 (58%) patients and first AD diagnosis in 43 (86%) patients. Allowing for the dates from the two approaches to be within 30 days, the code-based algorithm's success rates increased to 74%, 70% and 94%, respectively. Mini-Mental State Examination was the most commonly observed cognitive assessment in both approaches; however, of the 53 tests performed, only 19 results were observed in the coded data. CONCLUSIONS The code-based algorithm shows promise for identifying the first AD diagnosis. However, the reliability of using coded data to identify earliest indications of cognitive impairment and cognitive assessments is questionable. Additionally, CPRD is not a recommended data source to identify results of cognitive assessments.
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Affiliation(s)
| | - Urvi Desai
- Analysis Group Inc., Boston, Massachusetts, USA
| | | | - Jody Wen
- Analysis Group Inc., Boston, Massachusetts, USA
| | | | | | - Mark Belger
- Eli Lilly and Company (Lilly UK), Windlesham, Surrey, UK
| | | | - Carlos Martinez
- Institute for Epidemiology, Statistics and Informatics GmbH, Frankfurt, Germany
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Reed CC, Fan C, Koutlas NT, Shaheen NJ, Dellon ES. Food elimination diets are effective for long-term treatment of adults with eosinophilic oesophagitis. Aliment Pharmacol Ther 2017; 46:836-844. [PMID: 28877359 PMCID: PMC5659358 DOI: 10.1111/apt.14290] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 08/05/2017] [Accepted: 08/15/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND Limited data describe the long-term efficacy of dietary elimination in eosinophilic oesophagitis (EoE). AIM To assess the long-term outcomes of food elimination diets for treatment of adults with EoE. METHODS We conducted a retrospective cohort study at our centre analysing all EoE patients receiving a food elimination diet without concomitant steroids. Baseline data were abstracted using standardised collection forms. Follow-up data from a mean 24.9-month period were collected for patients with a histological response to a food elimination diet during and after food reintroduction. The main outcomes were symptomatic, endoscopic and histological responses. RESULTS Of 52 patients, 18 received a 6-food food elimination diet, 32 received targeted diet, and two received a 6-food food elimination diet with targeted elimination. There were 21 (40%) patients with an initial histological response. Responders reported less dysphagia after treatment (95% baseline vs 11%; P = .001) and at the end of follow-up (95% baseline vs 33%; P = .008). Significant and durable endoscopic improvements were recorded at the same time points: Endoscopic reference score: 3.2 vs 0.7; P = .001; and 3.2 vs 1.7; P = .06. Histological findings improved after the most restrictive diet in responders (49.8 vs 4.1 eosinophils per high-power field; P = .001) and remained suppressed in the 10 initial responders maintaining compliance at the end of follow-up (5.2 eosinophils per high-power field). CONCLUSIONS Among EoE patients responding to a food elimination diet and remaining adherent, maintenance dietary therapy produced durable long-term symptomatic, endoscopic and histological disease control. These long-term data confirm that a food elimination diet is an effective maintenance treatment option in select adults with EoE.
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Affiliation(s)
- C C Reed
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, and Center for Gastrointestinal Biology and Disease, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - C Fan
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, and Center for Gastrointestinal Biology and Disease, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - N T Koutlas
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, and Center for Gastrointestinal Biology and Disease, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - N J Shaheen
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, and Center for Gastrointestinal Biology and Disease, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - E S Dellon
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, and Center for Gastrointestinal Biology and Disease, University of North Carolina School of Medicine, Chapel Hill, NC, USA
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Reed CC, Lebrec J, Jones RW, Bruno G, Dell'Agnello G, Monkul ES, Andrews JS. [P2–307]: INTERMEDIATE CHANGES IN COGNITION PREDICT LONG TERM OUTCOMES IN MILD ALZHEIMER's DISEASE DEMENTIA. Alzheimers Dement 2017. [DOI: 10.1016/j.jalz.2017.06.961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Roy W. Jones
- Research Institute for the Care of Older PeopleBathUnited Kingdom
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Reed CC, Wolf WA, Cotton CC, Dellon ES. A visual analogue scale and a Likert scale are simple and responsive tools for assessing dysphagia in eosinophilic oesophagitis. Aliment Pharmacol Ther 2017; 45:1443-1448. [PMID: 28370355 PMCID: PMC5419874 DOI: 10.1111/apt.14061] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 02/10/2017] [Accepted: 03/05/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND While symptom scores have been developed to evaluate dysphagia in eosinophilic oesophagitis (EoE), their complexity may limit clinical use. AIM To evaluate a visual analogue scale (VAS) and a 10-point Likert scale (LS) for assessment of dysphagia severity before and after EoE treatment. METHODS We conducted a prospective cohort study enrolling consecutive adults undergoing out-patient endoscopy. Incident cases of EoE were diagnosed per consensus guidelines. At diagnosis and after 8 weeks of treatment, symptoms were measured using the VAS, LS and the Mayo Dysphagia Questionnaire (MDQ). The percentage change in scores before and after treatment were compared overall, in treatment responders (<15 eos/hpf) and non-responders, and in patients without baseline dilation. RESULTS In 51 EoE cases, the median VAS decreased from 3.6 at baseline to 1.4 post-treatment (71% decrease), the LS decreased from 6 to 2 (67%) and the MDQ decreased from 20 to 10 (49%). The VAS correlated with both the LS (R = 0.77; P < 0.0001) and MDQ (R = 0.46, P = 0.001). After stratification by histological response, the LS decreased 70% in responders vs. 13% in non-responders (P = 0.02). In patients who did not receive baseline dilation, both the VAS and LS decreased significantly more in the histological responders. CONCLUSIONS Both the VAS and LS were responsive to successful treatment as measured by histologic improvement. Because the VAS and LS are simple to administer and are responsive to treatment, they can provide an efficient and objective method for assessing dysphagia severity in EoE in clinical practice.
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Affiliation(s)
- C C Reed
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, Center for Gastrointestinal Biology and Disease, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - W A Wolf
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, Center for Gastrointestinal Biology and Disease, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - C C Cotton
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, Center for Gastrointestinal Biology and Disease, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - E S Dellon
- Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Diseases and Swallowing, Center for Gastrointestinal Biology and Disease, University of North Carolina School of Medicine, Chapel Hill, NC, USA
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Haro JM, Kahle-Wrobleski K, Bruno G, Belger M, Dell'Agnello G, Dodel R, Jones RW, Reed CC, Vellas B, Wimo A, Argimon JM. Analysis of burden in caregivers of people with Alzheimer's disease using self-report and supervision hours. J Nutr Health Aging 2014; 18:677-84. [PMID: 25226106 DOI: 10.1007/s12603-014-0500-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [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: 10/24/2022]
Abstract
OBJECTIVES This study aimed to describe the baseline characteristics of informal carers of community-living Alzheimer's disease (AD) patients by AD severity group and to identify factors associated with two measures of caregiver burden. DESIGN AND SETTING GERAS is a prospective observational study in France, Germany, and the UK, designed to assess costs and resource use associated with AD, for patients and their caregivers, stratified by disease severity. PARTICIPANTS 1497 community-dwelling AD patients and their primary caregivers. MEASUREMENTS Subjective caregiver burden assessed using the Zarit Burden Interview [ZBI] and time spent supervising patients (an objective measure of burden recorded using the Resource Utilization in Dementia instrument) during the month before the baseline visit were recorded. Separate multiple linear regression analyses using ZBI total score and caregiver supervision time as dependent variables were performed to identify patient and caregiver factors independently associated with caregiver burden. RESULTS Increasing AD severity was associated with both subjective caregiver burden (ZBI total score) and overall caregiver time, which includes supervision time (both p<0.001, ANOVA). Better patient functioning (on instrumental activities of daily living) was independently associated with both a lower ZBI total score and less supervision time, whereas higher levels of caregiver distress due to patient behavior were associated with greater caregiver burden. Other factors independently associated with an increased ZBI total score included younger caregiver age, caregiver self-reported depression, caring for a male patient, and longer time since AD diagnosis. Caregivers living with the patient, being a male caregiver, patient living in a rural location, higher patient behavioral problem subdomain scores for apathy and psychosis, more patient emergency room visits, not receiving food delivery and receiving financial support for caregiving were all associated with greater caregiver supervision time. CONCLUSION Our results show that subjective caregiver burden and caregiver time are influenced by different factors, reinforcing the need to consider both aspects of caregiving when trying to minimize the burden of AD. However, interventions that minimize caregiver distress and improve patient functioning may impact on both subjective and objective burden.
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Affiliation(s)
- J M Haro
- Kristin Kahle-Wrobleski, Global Health Outcomes, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, USA, Tel: +1 317 709 6666 Fax: +1 317 433 6590,
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Happich M, Kirson NY, Desai U, King S, Birnbaum HG, Price D, Belger M, Hunter CA, Lenox‐Smith AJ, Reed CC. P4‐339: EXCESS COSTS ASSOCIATED WITH POSSIBLE MISDIAGNOSIS OF ALZHEIMER'S DISEASE AMONG PATIENTS WITH VASCULAR DEMENTIA IN A UK CPRD POPULATION. Alzheimers Dement 2014. [DOI: 10.1016/j.jalz.2014.07.110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
| | | | - Urvi Desai
- Analysis Group, IncBostonMassachusettsUnited States
| | - Sarah King
- Analysis Group, Inc.BostonMassachusettsUnited States
| | | | - David Price
- Research in Real LifeOakingtonUnited Kingdom
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Wimo A, Reed CC, Dodel R, Belger M, Jones RW, Happich M, Argimon JM, Bruno G, Novick D, Vellas B, Haro JM. The GERAS Study: a prospective observational study of costs and resource use in community dwellers with Alzheimer's disease in three European countries--study design and baseline findings. J Alzheimers Dis 2014; 36:385-99. [PMID: 23629588 DOI: 10.3233/jad-122392] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
To address socioeconomic challenges associated with its increasing prevalence, data are needed on country-level resource use and costs associated with Alzheimer's disease (AD). GERAS is an 18-month observational study being conducted in France, Germany, and the U.K. (with an 18-month extension in France and Germany), aimed at determining resource use and total costs associated with AD, stratified by AD severity at baseline. Resource use information and time spent on informal care by non-professional caregivers was obtained using the Resource Utilization in Dementia instrument. Total baseline societal costs were based on four cost components: patient health care costs, patient social care costs, caregiver health care costs, and caregiver informal care costs. Overall, 1,497 community-dwelling patients with AD were analyzed at baseline. Estimated mean monthly total societal costs per patient at baseline differed significantly between groups with mild, moderate, and moderately severe/severe AD (p < 0.001 in each country): euro $1,418, euro 1,737, and euro 2,453 in France; euro 1,312, euro $2,412, and euro 3,722 in Germany; and euro 1,621, euro 1,836, andeuro 2,784 in the U.K., respectively. All cost components except caregiver health care costs increased with AD severity. Informal caregiver costs were the largest cost component accounting for about half to just over 60% of total societal costs, depending on country and AD severity group. In conclusion, GERAS study baseline results showed that country-specific costs increase with AD severity. Informal care costs formed the greatest proportion of total societal costs, increasing with AD severity independent of costing method. Longitudinal data will provide information on cost trends with disease progression.
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Affiliation(s)
- Anders Wimo
- KI Alzheimer's Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Stockholm, Sweden
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Goldoni S, Iozzo RA, Kay P, Campbell S, McQuillan A, Agnew C, Zhu JX, Keene DR, Reed CC, Iozzo RV. A soluble ectodomain of LRIG1 inhibits cancer cell growth by attenuating basal and ligand-dependent EGFR activity. Oncogene 2006; 26:368-81. [PMID: 16847455 DOI: 10.1038/sj.onc.1209803] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [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: 11/09/2022]
Abstract
Leucine-rich repeats and immunoglobulin-like domains-1 (LRIG1) is a transmembrane protein with an ectodomain containing 15 leucine-rich repeats (LRRs) homologous to mammalian decorin and the Drosophila kekkon1 gene. In this study, we demonstrate that a soluble ectodomain of LRIG1, containing only the LRRs, inhibits ligand-independent epidermal growth factor receptor (EGFR) activation and causes growth inhibition of A431, HeLa and MDA-468 carcinoma cells. In contrast, cells that do not express detectable levels of EGFR fail to respond to soluble LRIG1. However, when a functional EGFR gene is introduced in these cells, they become growth-inhibited by soluble LRIG1 protein. Furthermore, we demonstrate the existence of high-affinity (K(d)=10 nM) binding sites on the A431 cells that can be competitively displaced (up to 75%) by molar excess of EGF. Even more powerful effects are obtained with a chimeric proteoglycan harboring the N-terminus of decorin, substituted with a single glycosaminoglycan chain, fused to the LRIG1 ectodomain. Both proteins also inhibit ligand-dependent activation of the EGFR and extracellular signal-regulated protein kinase 1/2 signaling in a rapid and dose-dependent manner. These results suggest a novel mechanism of action evoked by a soluble ectodomain of LRIG1 protein that could modulate EGFR signaling and its growth-promoting activity. Attenuation of EGFR activity without physical downregulation of the receptor could represent a novel therapeutic approach toward malignancies in which EGFR plays a primary role in tumor growth and survival.
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Affiliation(s)
- S Goldoni
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Csordás G, Santra M, Reed CC, Eichstetter I, McQuillan DJ, Gross D, Nugent MA, Hajnóczky G, Iozzo RV. Sustained down-regulation of the epidermal growth factor receptor by decorin. A mechanism for controlling tumor growth in vivo. J Biol Chem 2000; 275:32879-87. [PMID: 10913155 DOI: 10.1074/jbc.m005609200] [Citation(s) in RCA: 183] [Impact Index Per Article: 7.6] [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: 11/06/2022] Open
Abstract
The small leucine-rich proteoglycan decorin interacts with the epidermal growth factor receptor (EGFR) and triggers a signaling cascade that leads to elevation of endogenous p21 and growth suppression. We demonstrate that decorin causes a sustained down-regulation of the EGFR. Upon stable expression of decorin, the EGFR number is reduced by approximately 40%, without changes in EGFR expression. However, EGFR phosphorylation is nearly completely abolished. Concurrently, decorin attenuates the EGFR-mediated mobilization of intracellular calcium and blocks the growth of tumor xenografts by down-regulating the EGFR kinase in vivo. Thus, decorin acts as an autocrine and paracrine regulator of tumor growth and could be utilized as an effective anti-cancer agent.
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Affiliation(s)
- G Csordás
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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Mahalingam B, Louis JM, Reed CC, Adomat JM, Krouse J, Wang YF, Harrison RW, Weber IT. Structural and kinetic analysis of drug resistant mutants of HIV-1 protease. Eur J Biochem 1999; 263:238-45. [PMID: 10429209 DOI: 10.1046/j.1432-1327.1999.00514.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mutants of HIV-1 protease that are commonly selected on exposure to different drugs, V82S, G48V, N88D and L90M, showed reduced catalytic activity compared to the wild-type protease on cleavage site peptides, CA-p2, p6pol-PR and PR-RT, critical for viral maturation. Mutant V82S is the least active (2-20% of wild-type protease), mutants N88D, R8Q, and L90M exhibit activities ranging from 20 to 40% and G48V from 50 to 80% of the wild-type activity. In contrast, D30N is variable in its activity on different substrates (10-110% of wild-type), with the PR-RT site being the most affected. Mutants K45I and M46L, usually selected in combination with other mutations, showed activities that are similar to (60-110%) or greater than (110-530%) wild-type, respectively. No direct relationship was observed between catalytic activity, inhibition, and structural stability. The mutants D30N and V82S were similar to wild-type protease in their stability toward urea denaturation, while R8Q, G48V, and L90M showed 1.5 to 2.7-fold decreased stability, and N88D and K45I showed 1.6 to 1.7-fold increased stability. The crystal structures of R8Q, K45I and L90M mutants complexed with a CA-p2 analog inhibitor were determined at 2.0, 1.55 and 1.88 A resolution, respectively, and compared to the wild-type structure. The intersubunit hydrophobic contacts observed in the crystal structures are in good agreement with the relative structural stability of the mutant proteases. All these results suggest that viral resistance does not arise by a single mechanism.
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Affiliation(s)
- B Mahalingam
- Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, USA
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Abstract
Comparative modeling targets 1, 3, 9 and 17 were predicted by alignment of multiple sequences and structures, when available, followed by minimization using the program AMMP. The minimization used improved potentials, and distance restraints for regions of common structure. New prediction procedures were evaluated. Three tested solvent corrections did not significantly improve the predictions. Target 17 had 85.3% sequence identity with the parent and no insertions or deletions. The prediction had a root-mean-square deviation from target 17 of 0.56 A on C alpha atoms, and 0.59 A for the ligand atoms, which verified the accuracy of the minimization. Targets 1, 3, and 9 had 36.4%, 46.7%, and 33.3% identity with the parent sequences, and predictions resulted in root-mean-square deviations for 79-85% of C alpha atoms of 1.49, 1.11, and 1.24 A, respectively. Conformational differences between parent and target crystal structures were difficult to predict. The use of distance restraints and multiple structures improved the positioning of gaps in sequence alignment. Distance restraints did not overcome errors in sequence alignment or ambiguities due to conformational variation in proteins. Predictions for targets 3 and 9 successfully reduced large deviations between parent and target structures.
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Affiliation(s)
- R W Harrison
- Department of Microbiology and Immunology, Kimmel Cancer Center, Jefferson Medical College, Philadelphia, Pennsylvania 19107, USA
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Wukasch DC, Malloy KP, Rubio PA, Reed CC, Sandiford FM, Reul GJ, Milam JD, Cooley DA. Fat embolization resulting from median sternotomy. Tex Med 1975; 71:35-41. [PMID: 1114459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Reed CC, Romagnoli A, Taylor DE, Clark DK. Particulate matter in bubble oxygenators. J Thorac Cardiovasc Surg 1974; 68:971-4. [PMID: 4421091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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