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Sommerhalter KM, Insaf TZ, Akkaya-Hocagil T, McGarry CE, Farr SL, Downing KF, Lui GK, Zaidi AN, Van Zutphen AR. Proximity to Pediatric Cardiac Surgical Care among Adolescents with Congenital Heart Defects in 11 New York Counties. Birth Defects Res 2018; 109:1494-1503. [PMID: 29152921 DOI: 10.1002/bdr2.1129] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/31/2017] [Accepted: 08/25/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Many individuals with congenital heart defects (CHDs) discontinue cardiac care in adolescence, putting them at risk of adverse health outcomes. Because geographic barriers may contribute to cessation of care, we sought to characterize geographic access to comprehensive cardiac care among adolescents with CHDs. METHODS Using a population-based, 11-county surveillance system of CHDs in New York, we characterized proximity to the nearest pediatric cardiac surgical care center among adolescents aged 11 to 19 years with CHDs. Residential addresses were extracted from surveillance records documenting 2008 to 2010 healthcare encounters. Addresses were geocoded using ArcGIS and the New York State Street and Address Maintenance Program, a statewide address point database. One-way drive and public transit time from residence to nearest center were calculated using R packages gmapsdistance and rgeos with the Google Maps Distance Matrix application programming interface. A marginal model was constructed to identify predictors associated with one-way travel time. RESULTS We identified 2522 adolescents with 3058 corresponding residential addresses and 12 pediatric cardiac surgical care centers. The median drive time from residence to nearest center was 18.3 min, and drive time was 30 min or less for 2475 (80.9%) addresses. Predicted drive time was longest for rural western addresses in high poverty census tracts (68.7 min). Public transit was available for most residences in urban areas but for few in rural areas. CONCLUSION We identified areas with geographic barriers to surgical care. Future research is needed to determine how these barriers influence continuity of care among adolescents with CHDs. Birth Defects Research 109:1494-1503, 2017.© 2017 Wiley Periodicals, Inc.
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Saha P, Potiny P, Tcheandjieu C, Fernandes SM, Romfh A, Bernstein D, Lui GK, Ingelsson E, Priest J. CONGENITAL HEART DISEASE CONFERS SUBSTANTIAL RISK OF ACQUIRED CARDIOVASCULAR DISEASE AMONGST BRITISH ADULTS. J Am Coll Cardiol 2018. [DOI: 10.1016/s0735-1097(18)31094-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Mainwaring RD, Patrick WL, Ibrahimiye AN, Watanabe N, Lui GK, Hanley FL. An Analysis of Left Ventricular Retraining in Patients With Dextro- and Levo-Transposition of the Great Arteries. Ann Thorac Surg 2018; 105:823-829. [DOI: 10.1016/j.athoracsur.2017.11.047] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 11/13/2017] [Accepted: 11/16/2017] [Indexed: 11/30/2022]
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Rösner A, Khalapyan T, Dalen H, McElhinney DB, Friedberg MK, Lui GK. Classic-Pattern Dyssynchrony in Adolescents and Adults With a Fontan Circulation. J Am Soc Echocardiogr 2018; 31:211-219. [DOI: 10.1016/j.echo.2017.10.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Indexed: 11/25/2022]
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Lui GK, Rogers IS, Ding VY, Hedlin HK, MacMillen K, Maron DJ, Sillman C, Romfh A, Dade TC, Haeffele C, Grady SR, McElhinney DB, Murphy DJ, Fernandes SM. Risk Estimates for Atherosclerotic Cardiovascular Disease in Adults With Congenital Heart Disease. Am J Cardiol 2017; 119:112-118. [PMID: 28247847 DOI: 10.1016/j.amjcard.2016.09.023] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 09/13/2016] [Accepted: 09/13/2016] [Indexed: 12/31/2022]
Abstract
The adult with congenital heart disease (CHD) is at risk of developing atherosclerotic cardiovascular disease (ASCVD). We performed a cross-sectional study to describe established ASCVD risk factors and estimate 10-year and lifetime risk of ASCVD in adults over age 18 with CHD of moderate or great complexity using 3 validated risk assessment tools-the Framingham Study Cardiovascular Disease Risk Assessment, the Reynolds Risk Score, and the ASCVD Risk Estimator. We obtained extensive clinical and survey data on 178 enrolled patients, with average age 37.1 ± 12.6 years, 51% men. At least 1 modifiable ASCVD risk factor was present in 70%; the 2 most common were overweight/obesity (53%) and systemic hypertension (24%). Laboratory data were available in 103 of the 178 patients. Abnormal levels of glycated hemoglobin, high-sensitivity C-reactive protein, and high-density lipoprotein were each found in around 30% of patients. The 10-year ASCVD predicted risk using all 3 tools was relatively low (i.e., at least 90% of patients <10% risk), yet the median estimated lifetime risk was 36%. In conclusion, ASCVD risk factors are prevalent in adults with CHD. The risk estimation tools suggest that this population is particularly vulnerable to ASCVD with aging and should undergo guideline-based screening and management of modifiable risk factors.
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Lin EY, Cohen HW, Bhatt AB, Stefanescu A, Dudzinski D, Yeh DD, Johnson J, Lui GK. Predicting Outcomes Using the Heart Failure Survival Score in Adults with Moderate or Complex Congenital Heart Disease. CONGENIT HEART DIS 2015; 10:387-95. [PMID: 25358483 PMCID: PMC4417083 DOI: 10.1111/chd.12229] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/21/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND Adults with congenital heart disease (CHD) face increased risk for morbidity and mortality with age, but few prognostic models exist. OBJECTIVE This study aims to assess whether the Heart Failure Survival Score (HFSS), which risk stratifies patients for heart transplantation, predicts outcomes in adults with moderate or complex CHD. METHODS This was a multicenter, retrospective study which identified 441 patients with moderate or complex CHD between 2005 and 2013, of whom 169 had all the HFSS parameters required to calculate the risk score. Because all study patients were deemed low risk by the HFSS, the score was dichotomized at the median (10.4). Outcomes included death, transplant or ventricular assist device (VAD), arrhythmia requiring treatment, nonelective cardiovascular (CV) hospitalizations, and the composite. Associations of mean HFSS and HFSS <10.4 with each outcome were assessed. RESULTS The cohort had mean ± standard deviation age of 33.6 ± 12.6 years, peak VO2 21.8 ± 7.5 mL/kg/min, HFSS of 10.45 ± 0.88, and median years follow-up of 2.7 (1.1, 5.2). There were five deaths (2.8%), no transplants or VADs, 25 arrhythmias (14.8%), 22 CV hospitalizations (13%), and 39 composites (23.1%). Lower mean HFSS was observed for patients who died (9.6 ± 0.83 vs. 10.5 ± 0.87, P = .02), arrhythmia requiring treatment (10.0 ± 0.70 vs. 10.5 ± 0.89, P = .005), CV hospitalizations (9.9 ± 0.73 vs. 10.5 ± 0.88, P = .002), and the composite (10.0 ± 0.70 vs. 10.6 ± 0.89, P < .001). The positive and negative predictive values of HFSS <10.4 for the composite were 34% and 88% respectively, with sensitivity and specificity 74% and 56%. CONCLUSIONS Although a low HFSS was significantly associated with outcomes, it did not adequately risk stratify adults with CHD, whose heterogeneous pathophysiology differs from that of the acquired heart failure population. Further studies are warranted to provide a more accurate prognosis.
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Wilson KD, Shen P, Fung E, Karakikes I, Zhang A, InanlooRahatloo K, Odegaard J, Sallam K, Davis RW, Lui GK, Ashley EA, Scharfe C, Wu JC. A Rapid, High-Quality, Cost-Effective, Comprehensive and Expandable Targeted Next-Generation Sequencing Assay for Inherited Heart Diseases. Circ Res 2015; 117:603-11. [PMID: 26265630 DOI: 10.1161/circresaha.115.306723] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 07/27/2015] [Indexed: 12/21/2022]
Abstract
RATIONALE Thousands of mutations across >50 genes have been implicated in inherited cardiomyopathies. However, options for sequencing this rapidly evolving gene set are limited because many sequencing services and off-the-shelf kits suffer from slow turnaround, inefficient capture of genomic DNA, and high cost. Furthermore, customization of these assays to cover emerging targets that suit individual needs is often expensive and time consuming. OBJECTIVE We sought to develop a custom high throughput, clinical-grade next-generation sequencing assay for detecting cardiac disease gene mutations with improved accuracy, flexibility, turnaround, and cost. METHODS AND RESULTS We used double-stranded probes (complementary long padlock probes), an inexpensive and customizable capture technology, to efficiently capture and amplify the entire coding region and flanking intronic and regulatory sequences of 88 genes and 40 microRNAs associated with inherited cardiomyopathies, congenital heart disease, and cardiac development. Multiplexing 11 samples per sequencing run resulted in a mean base pair coverage of 420, of which 97% had >20× coverage and >99% were concordant with known heterozygous single nucleotide polymorphisms. The assay correctly detected germline variants in 24 individuals and revealed several polymorphic regions in miR-499. Total run time was 3 days at an approximate cost of $100 per sample. CONCLUSIONS Accurate, high-throughput detection of mutations across numerous cardiac genes is achievable with complementary long padlock probe technology. Moreover, this format allows facile insertion of additional probes as more cardiomyopathy and congenital heart disease genes are discovered, giving researchers a powerful new tool for DNA mutation detection and discovery.
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Watanabe N, Mainwaring RD, Carrillo SA, Lui GK, Reddy VM, Hanley FL. Left Ventricular Retraining and Late Arterial Switch for d-Transposition of the Great Arteries. Ann Thorac Surg 2015; 99:1655-61; discussion 1661-3. [DOI: 10.1016/j.athoracsur.2014.12.084] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Revised: 12/20/2014] [Accepted: 12/30/2014] [Indexed: 11/25/2022]
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Lui GK, Fernandes S, McElhinney DB. Management of cardiovascular risk factors in adults with congenital heart disease. J Am Heart Assoc 2014; 3:e001076. [PMID: 25359401 PMCID: PMC4338694 DOI: 10.1161/jaha.114.001076] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 10/01/2014] [Indexed: 01/21/2023]
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Tso GJ, Lee JM, Shaban NM, Lui GK, Trivedi HA, Cohen MN, Bernstein PS, Taub CC. Normal Echocardiographic Measurements in Uncomplicated Pregnancy, a Single Center Experience. J Cardiovasc Dis Res 2014. [DOI: 10.5530/jcdr.2014.2.2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Zhang L, Lin EY, Bhandari D, Pamerla M, Lui GK, Taub CC. Utilization of Real-time 3D Transesophageal Echocardiography in an Urban Academic Medical Center. J Cardiovasc Dis Res 2014. [DOI: 10.5530/jcdr.2014.2.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Zhou L, Lui GK, Shenoy R, Taub CC. Coarctation of the aorta associated with Dandy-Walker variant. J Cardiovasc Dis Res 2014; 4:182-6. [PMID: 24396258 DOI: 10.1016/j.jcdr.2013.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 06/30/2013] [Indexed: 11/25/2022] Open
Abstract
This article reports a rare case of coarctation of the aorta associated with Dandy-Walker variant in a 17-year-old girl. Differential diagnoses of coarctation of the aorta and Dandy-Walker variant are extensively discussed. In addition, standard surgical treatment of coarctation as well as new approaches such as endovascular stenting are described in detail to provide therapeutic insights into her management. Although surgical or endovascular repair of coarctation results in significant improvement of systemic hypertension and is associated with better survival, cardiovascular complications are still very common. Thus, long-term follow-up after repair is required, and high-quality imaging studies such as echocardiography, CT and MRI are warranted.
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Mongeon FP, Gurvitz MZ, Broberg CS, Aboulhosn J, Opotowsky AR, Kay JD, Valente AM, Earing MG, Lui GK, Fernandes SM, Gersony DR, Cook SC, Ting JG, Nickolaus MJ, Landzberg MJ, Khairy P. Aortic Root Dilatation in Adults with Surgically Repaired Tetralogy of Fallot. Circulation 2013; 127:172-9. [DOI: 10.1161/circulationaha.112.129585] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Zwany SK, Lui GK, Scheinfeld MH, Levsky JM. Making complex adult congenital heart disease a little simpler. Semin Roentgenol 2012; 47:289-301. [PMID: 22657118 DOI: 10.1053/j.ro.2012.01.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kazmierski WM, Ferguson RD, Knapp RJ, Lui GK, Yamamura HI, Hruby VJ. Reduced peptide bond cyclic somatostatin based opioid octapeptides Synthesis, conformational properties and pharmacological characterization. ACTA ACUST UNITED AC 2009; 39:401-14. [PMID: 1358847 DOI: 10.1111/j.1399-3011.1992.tb01444.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The conformational and pharmacological properties that result from peptide bond reduction as well as the use of secondary amino acids in a series of cyclic peptides related to the mu opioid receptor selective antagonist D-Phe1-Cys2-Tyr3-D-Trp4-Orn5-Thr6-Pen7+ ++-Thr8-NH2 (IV), have been investigated. Peptide analogues that contain [CH2NH] and [CH2N] pseudo-peptide bonds (in primary and secondary amino acids, respectively) were synthesized on a solid support. Substitution of Tyr3 in IV by the cyclic, secondary amino acid 1,2,3,4-tetrahydroisoquinoline carboxylate (Tic) and of D-Trp4 with D-1,2,3,4-tetrahydro-beta-carboline(D-Tca4), gave peptides 4 and 1, respectively. Both analogues displayed reduced affinities for mu opioid receptors. Conformational analysis based on extensive NMR investigations demonstrated that the backbone conformations of 1 and 4 are similar to those of the potent and selective analogue D-Phe-Cys-Tyr-D-Trp-Lys-Thr-Pen-Thr-NH2 (I), while the conformational properties of the side chains of Tic3 (4) and D-Tca4 (1) resulted in topographical properties that were not well recognized by the mu opioid receptor. Peptide bond modifications were made including (Tyr3-psi[CH2NH]-D-Trp4), 3; (Tyr3-psi[CH2N]-D-Tca4), 2; and (Cys2-psi[CH2N]-Tic3), 6. These analogues showed decreases in their mu opioid receptor affinities relative to the parent compounds IV, 1, and 4, respectively. 1H NMR based conformational analysis in conjunction with receptor binding data led to the conclusion that the reduced peptide bonds in 2, 3, 5, and 6 do not contribute to the process of discrimination between mu and delta opioid receptors, and in spite of their different dynamic behaviors (relative to 1 and 4), they are still capable of attaining similar receptor bound conformations, possibly due to their increased flexibility.
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Hruby VJ, Toth G, Gehrig CA, Kao LF, Knapp R, Lui GK, Yamamura HI, Kramer TH, Davis P, Burks TF. Topographically designed analogues of [D-Pen,D-Pen5]enkephalin. J Med Chem 1991; 34:1823-30. [PMID: 1648137 DOI: 10.1021/jm00110a010] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The conformationally restricted, cyclic disulfide-containing delta opioid receptor selective enkephalin analogue [D-Pen2,D-Pen5]enkephalin (1, DPDPE) was systematically modified topographically by addition of a methyl group at either the pro-S or pro-R position of the beta carbon of an L-Phe4 or D-Phe4 residue to give [(2S,3S)-beta-MePhe4]DPDPE (2), [(2R,3R)-beta-MePhe4]DPDPE (3), [(2S,3R)-beta-MePhe4]DPDPE (4), and [(2R,3S)-beta-MePhe4]DPDPE (5). The four corresponding isomers were prepared in which the beta-methylphenylalanine residue was p-nitro substituted, that is with a beta-methyl-p-nitrophenylalanine (beta-Me-p-NO2Phe) residue, to give [(2S,3S)-beta-Me-p-NO2Phe4]DPDPE (6), [(2R,3R)-beta-Me-p-NO2Phe4]DPDPE (7), [(2S,3R)-beta-Me-p-NO2Phe4] DPDPE (8), and [(2R,3S)-beta-Me-p-NO2Phe4]DPDPE (9), respectively. The potency and selectivity (delta vs mu opioid receptor) were evaluated by radioreceptor binding assays in the rat brain using [3H]CTOP (mu ligand) and [3H]DPDPE (delta ligand) and by bioassay with mouse vas deferens (MVD, delta receptor assay) and guinea pig ileum (GPI, mu receptor assay). The eight analogues of DPDPE showed highly variable binding and bioassay activities particularly at the delta opioid receptor (4 orders of magnitude), but also at the mu opioid receptor, which led to large differences (3 orders of magnitude) in receptor selectivity. For example, [(2S,3S)-beta-MePhe4]DPDPE (2) is 1800-fold selective in binding to the delta vs mu receptor, making it one of the most selective delta opioid receptor ligands in the enkephalin series as assessed by the rat brain binding assay, whereas the corresponding (2R,3R)-beta-Me-p-NO2Phe-containing analogue 9 is only 4.5-fold selective (nonselective) in this same assay. On the other hand, in the bioassay systems, [(2S,3S)-beta-Me-p-NO2Phe4]DPDPE (5) is more potent than DPDPE and 8800-fold selective for the MVD (delta receptor) vs the GPI (mu receptor), making it the most highly selective ligand in this series for the delta opioid receptor on the basis of these bioassays. In these assay systems, the (2R,3S)-beta-MePhe4-containing analogue 5 had very weak potency and virtually no receptor selectivity (4.4-fold). These results demonstrate that topographical modification alone in a conformationally restricted peptide ligand can significantly modulate both potency and receptor selectivity of peptide ligands that have multiple sites of biological activity and suggest that this approach may have general application to peptide ligand design.
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Hruby VJ, Fang SA, Knapp R, Kazmierski W, Lui GK, Yamamura HI. Cholecystokinin analogues with high affinity and selectivity for brain membrane receptors. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1990; 35:566-73. [PMID: 2401597 DOI: 10.1111/j.1399-3011.1990.tb00263.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A series of CCK analogues in which positions 28 and 31 have been replaced by N-methylnorleucine residues have been synthesized. It has been found that most of these N-methylnorleucine containing analogues of CCK are highly potent and some are extraordinarily selective for the central vs. peripheral receptor in two animal models (guinea pig and rat). [N-MeNle28,31]CCK26-33 nonsulfated exhibited both high potency (IC50 = 0.13 nM) and selectivity for central vs. peripheral receptors. The pancrease to brain cortex binding affinity ratio for this analogue is 5100 in the rat model. NMR studies reveal that there is cis/trans isomerism about the N-methylnorleucine residue that may be related to high selectivity.
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Hawkins KN, Knapp RJ, Lui GK, Gulya K, Kazmierski W, Wan YP, Pelton JT, Hruby VJ, Yamamura HI. [3H]-[H-D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2] ([3H]CTOP), a potent and highly selective peptide for mu opioid receptors in rat brain. J Pharmacol Exp Ther 1989; 248:73-80. [PMID: 2563293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The cyclic, conformationally restricted octapeptide [3H]-[H-D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2] ([3H]CTOP) was synthesized and its binding to mu opioid receptors was characterized in rat brain membrane preparations. Association rates (k+1) of 1.25 x 10(8) M-1 min-1 and 2.49 x 10(8) M-1 min-1 at 25 and 37 degrees C, respectively, were obtained, whereas dissociation rates (k-1) at the same temperatures were 1.93 x 10(-2) min-1 and 1.03 x 10(-1) min-1 at 25 and 37 degrees C, respectively. Saturation isotherms of [3H]CTOP binding to rat brain membranes gave apparent Kd values of 0.16 and 0.41 nM at 25 and 37 degrees C, respectively. Maximal number of binding sites in rat brain membranes were found to be 94 and 81 fmol/mg of protein at 25 and 37 degrees C, respectively. [3H]CTOP binding over a concentration range of 0.1 to 10 nM was best fit by a one site model consistent with binding to a single site. The general effect of different metal ions and guanyl-5'-yl-imidodiphosphate on [3H]CTOP binding was to reduce its affinity. High concentrations (100 mM) of sodium also produced a reduction of the apparent mu receptor density. Utilizing the delta opioid receptor specific peptide [3H]-[D-Pen2,D-Pen5]enkephalin, CTOP appeared to be about 2000-fold more specific for mu vs. delta opioid receptor than naloxone. Specific [3H]CTOP binding was inhibited by a large number of opioid or opiate ligands.(ABSTRACT TRUNCATED AT 250 WORDS)
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Kazmierski W, Wire WS, Lui GK, Knapp RJ, Shook JE, Burks TF, Yamamura HI, Hruby VJ. Design and synthesis of somatostatin analogues with topographical properties that lead to highly potent and specific mu opioid receptor antagonists with greatly reduced binding at somatostatin receptors. J Med Chem 1988; 31:2170-7. [PMID: 2903246 DOI: 10.1021/jm00119a019] [Citation(s) in RCA: 114] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A series of conformationally restricted, cyclic octapeptides containing a conformationally stable tetrapeptide sequence related to somatostatin, -Tyr-D-Trp-Lys-Thr-, as a template, were designed and synthesized with the goal of developing highly potent and selective mu opioid antagonists with minimal or no somatostatin-like activity. Three distinct structures of the peptide became targets of chemical modifications and constraints; the N- and C-terminal amino acids and the cyclic 20-membered ring moiety. Based on the conformational analysis of active and inactive analogues of the parent peptide D-Phe1-Cys2-Tyr3-D-Trp4-Lys5-Thr6-Pen7+ ++-Thr8-NH2, CTP (Kazmierski, W.; Hruby, V. J. Tetrahedron 1988, 44, 697-710), we designed analogues to include the tetrahydroisoquinolinecarboxylate (Tic) moiety as the N-terminal amino acid instead of D-Phe, since Tic can exist only as a gauche (-) or a gauche (+) conformer. In this series, the following peptides were synthesized and pharmacologically evaluated: D-Tic-Cys-Tyr-D-Trp-Lys-Thr-Pen-Thr-NH2 (TCTP), D-Tic-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (TCTOP), and D-Tic-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 (TCTAP). In rat brain membrane opioid radioligand binding assays, all three peptides displayed high affinity for mu opioid receptors (IC50 = 1.2, 1.4, 1.2 nM, respectively), and exceptional mu vs delta opioid receptor selectivity: 7770, 11,396, and 1060, respectively. TCTOP and TCTAP also possess exceptional mu vs somatostatin receptor selectivity: 14,574 and 28,613, respectively. In the peripheral in vitro GPI bioassay, TCTP, TCTOP, and TCTAP were highly effective antagonists of the potent mu opioid receptor agonist PL017, with pA2 = 8.69 for TCTAP, 8.10 for TCTP, and 7.38 for TCTOP. Our results show that a 10-fold higher affinity and selectivity for mu opioid receptors (in both central and peripheral studies) over delta and somatostatin receptor was gained as a result of the D-Tic1 substitution. These three peptides, TCTP, TCTOP, and TCTAP, are the most potent and selective mu opioid antagonists known. CTP has been shown to possess prolonged biological action, much longer than that of naloxone. This renders these analogues potentially useful ligands for investigating the physiological functions of the mu opioid receptor. Analogues of TCTP in which the 20-membered disulfide ring was contracted by deletion of D-Trp4, and/or Lys5, and/or Thr6 led to compounds with greatly reduced potency at the mu opioid receptor.(ABSTRACT TRUNCATED AT 400 WORDS)
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Serra M, Mei L, Roeske WR, Lui GK, Watson M, Yamamura HI. The intact human neuroblastoma cell (SH-SY5Y) exhibits high-affinity [3H]pirenzepine binding associated with hydrolysis of phosphatidylinositols. J Neurochem 1988; 50:1513-21. [PMID: 3361307 DOI: 10.1111/j.1471-4159.1988.tb03038.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The binding of [3H]pirenzepine to a human neuroblastoma cell line (SH-SY5Y) and its correlation with hydrolysis of phosphatidylinositols were characterized. Specific [3H]pirenzepine binding to intact cells was rapid, reversible, saturable, and of high affinity. Kinetic studies yielded association (k+1) and dissociation (k-1) rate constants of 5.2 +/- 1.4 X 10(6) M-1 min-1 and 1.1 +/- 0.06 X 10(-1) min-1, respectively. Saturation experiments revealed a single class of binding sites (nH = 1.1) for the radioligand with a total binding capacity of 160 +/- 33 fmol/mg protein and an apparent dissociation constant of 13 nM. The specific [3H]pirenzepine binding was inhibited by the presence of selected muscarinic drugs. The order of antagonist potency was atropine sulfate greater than pirenzepine greater than AF-DX 116, with K0.5 of 0.53 nM, 2.2 nM, and 190 nM, respectively. The binding properties of [3H](-)-quinuclidinyl benzilate and its quaternary derivative [3H](-)-methylquinuclidinyl benzilate were also investigated. The muscarinic agonist carbachol stimulated formation of inositol phosphates which could be inhibited by muscarinic antagonists. The inhibition constants of pirenzepine and AF-DX 116 were 11 nM and 190 nM, respectively. In conclusion, we show that the nonclassical muscarinic receptor antagonist [3H]pirenzepine identifies a high-affinity population of muscarinic sites which is associated with hydrolysis of phosphatidylinositols in this human neuroblastoma cell line.
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Hawkins KN, Knapp RJ, Gehlert DR, Lui GK, Yamamura MS, Roeske LC, Hruby VJ, Yamamura HI. Quantitative autoradiography of [3H]CTOP binding to mu opioid receptors in rat brain. Life Sci 1988; 42:2541-51. [PMID: 2898716 DOI: 10.1016/0024-3205(88)90322-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
[3H]H-D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 ([3H]CTOP), a potent and highly selective mu opioid antagonist, was used to localize the mu receptors in rat brain by light microscopic autoradiography. Radioligand binding studies with [3H]CTOP using slide-mounted tissue sections of rat brain produced a Kd value of 1.1 nM with a Bmax value of 79.1 fmol/mg protein. Mu opioid agonists and antagonists inhibited [3H]CTOP binding with high affinity (IC50 values of 0.2-2.4 nM), while the delta agonist DPDPE, delta antagonist ICI 174,864, and kappa agonist U 69, 593 were very weak inhibitors of [3H]CTOP binding (IC50 values of 234-3631 nM). Light microscopic autoradiography of [3H]CTOP binding sites revealed regions of high density (nucleus of the solitary tract, clusters in the caudate-putamen, interpeduncular nucleus, superior and inferior colliculus, subiculum, substantia nigra zona reticulata, medial geniculate, locus coeruleus and dorsal motor nucleus of the vagus) and regions of moderate labeling (areas outside of clusters in the caudate-putamen, cingulate cortex, claustrum and nucleus accumbens). The cerebral cortex (parietal) showed a low density of [3H]CTOP binding.
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