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Ahn S, Phillips AG. Dopaminergic correlates of sensory-specific satiety in the medial prefrontal cortex and nucleus accumbens of the rat. J Neurosci 1999; 19:RC29. [PMID: 10493774 PMCID: PMC6782999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
Changes in dopamine (DA) efflux in the medial prefrontal cortex and nucleus accumbens of rats were monitored using in vivo microdialysis during sensory-specific satiety experiments. Rats consumed significant amounts of a palatable food during an initial meal but ate little when the same food was available as a second meal. In contrast, rats given a different palatable food ate a significant quantity during the second meal. DA efflux in both brain regions reflected this difference in food intake, indicating that DA activity is influenced by changes in the deprivation state of animals and sensory incentive properties of food. Given the proposed role of DA in motivated behaviors, these findings suggest that DA efflux may signal the relative incentive salience of foods and thus is a determinant of the pattern of food consumption observed in sensory-specific satiety.
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Speare R, Ahn S. Eradicating head lice in a nursing home. AUSTRALIAN FAMILY PHYSICIAN 1999; 28:915-7. [PMID: 10561891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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353
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Ahn S, Ginty DD, Linden DJ. A late phase of cerebellar long-term depression requires activation of CaMKIV and CREB. Neuron 1999; 23:559-68. [PMID: 10433267 DOI: 10.1016/s0896-6273(00)80808-9] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Recently, it has been shown that cerebellar LTD has a late phase that may be blocked by protein synthesis inhibitors. To understand the mechanisms underlying the late phase, we interfered with the activation of transcription factors that might couple synaptic activation to protein synthesis. Particle-mediated transfection of cultured Purkinje neurons with an expression vector encoding a dominant inhibitory form of CREB resulted in a nearly complete blockade of the late phase. Kinases that activate CREB were inhibited, and LTD was assessed. Inhibition of PKA or the MAPK/RSK cascades were without effect on the late phase, while constructs designed to interfere with CaMKIV function attenuated the late phase. These results indicate that the activation of CaMKIV and CREB are necessary to establish a late phase of cerebellar LTD.
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354
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Ahn S, Maudsley S, Luttrell LM, Lefkowitz RJ, Daaka Y. Src-mediated tyrosine phosphorylation of dynamin is required for beta2-adrenergic receptor internalization and mitogen-activated protein kinase signaling. J Biol Chem 1999; 274:1185-8. [PMID: 9880482 DOI: 10.1074/jbc.274.3.1185] [Citation(s) in RCA: 222] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Some forms of G protein-coupled receptor signaling, such as activation of mitogen-activated protein kinase cascade as well as resensitization of receptors after hormone-induced desensitization, require receptor internalization via dynamin-dependent clathrin-coated pit mechanisms. Here we demonstrate that activation of beta2-adrenergic receptors (beta2-ARs) leads to c-Src-mediated tyrosine phosphorylation of dynamin, which is required for receptor internalization. Two tyrosine residues, Tyr231 and Tyr597, are identified as the major phosphorylation sites. Mutation of these residues to phenylalanine dramatically decreases the c-Src-mediated phosphorylation of dynamin following beta2-AR stimulation. Moreover, expression of Y231F/Y597F dynamin inhibits beta2-AR internalization and the isoproterenol-stimulated mitogen-activated protein kinase activation. Thus, agonist-induced, c-Src-mediated tyrosine phosphorylation of dynamin is essential for its function in clathrin mediated G protein-coupled receptor endocytosis.
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355
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Sung HJ, Yoon T, Ahn S. Application of PIM for Manufacturing WC-Co Milling Inserts. ACTA ACUST UNITED AC 1999. [DOI: 10.2497/jjspm.46.887] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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356
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Selvais PL, Donckier JE, Robert A, Laloux O, van Linden F, Ahn S, Ketelslegers JM, Rousseau MF. Cardiac natriuretic peptides for diagnosis and risk stratification in heart failure: influences of left ventricular dysfunction and coronary artery disease on cardiac hormonal activation. Eur J Clin Invest 1998; 28:636-42. [PMID: 9767358 DOI: 10.1046/j.1365-2362.1998.00338.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Cardiac natriuretic peptides are activated in heart failure. However, their diagnostic and prognostic values have not been compared under the routine conditions of an outpatient practice. METHODS We studied the diagnostic and prognostic value of plasma N- and C-terminal peptides of the atrial natriuretic factor prohormone (N-proANF and ANF respectively) and brain natriuretic peptide (BNP) to evaluate the severity of congestive heart failure (CHF) as reflected by the New York Heart Association (NYHA) classification and to predict its 2-year mortality. Peripheral plasma concentrations of the three natriuretic peptides were measured in 27 normal subjects (CTR), in 32 patients with coronary artery disease (CAD) and normal left ventricular ejection fraction and in 101 patients with chronic CHF in functional classes I and II (n = 61) or III and IV (n = 40). RESULTS Plasma concentrations of the three peptides increased in the presence of CHF in relation to its severity (P < 0.01). BNP was unable to distinguish CTR from CAD, just as ANF could not differentiate CAD from CHF I-II; only N-proANF displayed a significant and continuous increase from CTR to CAD, CHF I-II and III-IV. Receiver-operating characteristic curves showed better evaluation of the degree of CHF by BNP than by ANF or ejection fraction (P < 0.05). Assessment of the 2-year prognosis revealed that N-proANF and BNP were the best independent predictors of outcome after the NYHA classification. These peptides identify a very high-mortality group. CONCLUSION Plasma N-proANF and BNP concentrations are good indicators of the severity and prognosis of CHF in an outpatient practice. CAD does not stimulate BNP as long as ventricular dysfunction is not present, although increased N-proANF levels in this setting suggest an early humoral activation.
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Musil CM, Ahn S, Haug M, Warner C, Morris D, Duffy E. Health problems and health actions among community-dwelling older adults: results of a health diary study. Appl Nurs Res 1998; 11:138-47. [PMID: 9757614 DOI: 10.1016/s0897-1897(98)80142-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This study examined the health problems and health actions reported by a sample of older adults (N = 60) who maintained health diaries over a 4-week period. The diary sample was 78% (n = 47) White; 52% (n = 31) were women, with a mean age of 75 years (SD = 5.3). Content analysis was used to examine the types of health problems reported in the diaries, which health problems were likely to be considered an illness, and what health actions were reported. Respondents reported an average of four different types of health problems over the 4-week diary period. There were differences in symptom reports related to gender, age, or race. The most frequently reported health problems were musculoskeletal problems (n = 38), runny nose and respiratory problems (n = 24), gastrointestinal problems (n = 22), and headaches (n = 22). Only 36% of all health problems were considered to be illnesses. Subjects recorded a number of health actions in response to their health complaints, including over-the-counter (OTC) medication use (83%), prescription medication use (53%), self-care activities (72%), and professional consultation (43%). Specific strategies that subjects used to deal with various health problems, implications of the findings, and the usefulness of health diaries as a clinical tool are discussed.
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358
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Ahn S, Lisitza N, Warren WS. Intermolecular zero-quantum coherences of multi-component spin systems in solution NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 1998; 133:266-272. [PMID: 9716467 DOI: 10.1006/jmre.1998.1461] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Intermolecular zero-quantum coherences (iZQC) induced by the dipolar demagnetizing field can give both P- and N-type cross peaks. This paper shows that the relative intensities of the two types of iZQC peaks follow a simple relation, tan2 (theta/2), from both the quantum (spin density matrix) and classical (modified Bloch equation) calculations. The experimental data and numerical simulations agree well with the prediction. In addition, higher-order iZQCs are experimentally examined for the first time and are explained by the quantum picture in which dipolar couplings convert four-spin operators into observable magnetization. Copyright 1998 Academic Press.
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Warren WS, Ahn S, Mescher M, Garwood M, Ugurbil K, Richter W, Rizi RR, Hopkins J, Leigh JS. MR imaging contrast enhancement based on intermolecular zero quantum coherences. Science 1998; 281:247-51. [PMID: 9657717 DOI: 10.1126/science.281.5374.247] [Citation(s) in RCA: 210] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A new method for magnetic resonance imaging (MRI) based on the detection of relatively strong signal from intermolecular zero-quantum coherences (iZQCs) is reported. Such a signal would not be observable in the conventional framework of magnetic resonance; it originates in long-range dipolar couplings (10 micrometers to 1 millimeter) that are traditionally ignored. Unlike conventional MRI, where image contrast is based on variations in spin density and relaxation times (often with injected contrast agents), contrast with iZQC images comes from variations in the susceptibility over a distance dictated by gradient strength. Phantom and in vivo (rat brain) data confirm that iZQC images give contrast enhancement. This contrast might be useful in the detection of small tumors, in that susceptibility correlates with oxygen concentration and in functional MRI.
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Mortman RE, Masyr S, Ahn S. Instrumenting the isthmus: navigating the roots of permanent mandibular molars. DENTISTRY TODAY 1998; 17:66-7, 70-1. [PMID: 9796460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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361
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Lee MH, Ahn S, Kim SS. Ablation of manifest left free wall accessory pathways with polarity reversal mapping: ventricular approach. Yonsei Med J 1998; 39:202-13. [PMID: 9664824 DOI: 10.3349/ymj.1998.39.3.202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Polarity reversal mapping for localization of the left free wall accessory pathway (AP) at the atrial insertion site has been shown to be effective for successful ablation, but this technique requires atrial septal puncture. We evaluated the safety, efficacy, and reproducibility of two dimensional polarity reversal mapping at the ventricular insertion site of the accessory pathway without atrial septal puncture in symptomatic patients with manifested left free wall AP. Polarity reversal mapping under the mitral annulus by transaortic approach was performed in 10 consecutive patients with conventional ablation catheter (6 French, 4 mm tip, 2 mm interelectrode distance), during sinus rhythm or atrial pacing. A low set high, bandpass filter (0.005-400Hz) was used. Radiofrequency (RF) ablation was performed at the site of ventricular electrocardiogram polarity reversal during sinus rhythm. Polarity reversal was identified in all patients at the ventricular side of the mitral annulus. Ablation was successful in all patients without complications. The procedure time was 86.0 +/- 21.1 min, the fluoroscopic exposure time was 16 +/- 12 min, the number of RF applications was 8 +/- 6, the power level 21 +/- 7 watts, and the time to initial AP block was 3.0 +/- 0.9 sec. Polarity reversal mapping is a safe and efficient technique at the ventricular insertion site. This technique might be complementary to the currently-utilized activation mapping technique.
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362
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Stauffer TP, Ahn S, Meyer T. Receptor-induced transient reduction in plasma membrane PtdIns(4,5)P2 concentration monitored in living cells. Curr Biol 1998; 8:343-6. [PMID: 9512420 DOI: 10.1016/s0960-9822(98)70135-6] [Citation(s) in RCA: 740] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Although phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) is a well-characterized precursor for the second messengers inositol 1,4,5-trisphosphate, diacylglycerol [1] and phosphatidylinositol 3,4,5-trisphosphate [2], it also interacts with the actin-binding proteins profilin and gelsolin [3], as well as with many signaling molecules that contain pleckstrin homology (PH) domains [4]. It is conceivable that stimuli received by receptors in the plasma membrane could be sufficiently strong to decrease the PtdIns(4,5)P2 concentration; this decrease could alter the structure of the cortical cytoskeleton and modulate the activity of signaling molecules that have PH domains. Here, we tested this hypothesis by using an in vivo fluorescent indicator for PtdIns(4,5)P2, by tagging the PH domain of phospholipase C delta 1 (PLC-delta 1) with the green fluorescent protein (GFP-PH). When expressed in cells, GFP-PH was found to be enriched at the plasma membrane. Binding studies in vitro and mutant analysis suggested that GFP-PH bound PtdIns(4,5)P2 selectively over other phosphatidylinositol lipids. Strikingly, receptor stimulation induced a transient dissociation of GFP-PH from the plasma membrane, suggesting that the concentration of PtdIns(4,5)P2 in the plasma membrane was effectively lowered. This transient dissociation was blocked by the PLC inhibitor U73122 but was not affected by the phosphoinositide (PI) 3-kinase inhibitor wortmannin, suggesting that it is mostly mediated by PLC and not by PI 3-kinase activation. Overall, our studies show that PtdIns(4,5)P2 can have second messenger functions of its own, by mediating a transient dissociation of proteins anchored in the plasma membrane.
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Ahn S, Olive M, Aggarwal S, Krylov D, Ginty DD, Vinson C. A dominant-negative inhibitor of CREB reveals that it is a general mediator of stimulus-dependent transcription of c-fos. Mol Cell Biol 1998; 18:967-77. [PMID: 9447994 PMCID: PMC108809 DOI: 10.1128/mcb.18.2.967] [Citation(s) in RCA: 435] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Several studies have characterized the upstream regulatory region of c-fos, and identified cis-acting elements termed the cyclic AMP (cAMP) response elements (CREs) that are critical for c-fos transcription in response to a variety of extracellular stimuli. Although several transcription factors can bind to CREs in vitro, the identity of the transcription factor(s) that activates the c-fos promoter via the CRE in vivo remains unclear. To help identify the trans-acting factors that regulate stimulus-dependent transcription of c-fos via the CREs, dominant-negative (D-N) inhibitor proteins that function by preventing DNA binding of B-ZIP proteins in a dimerization domain-dependent fashion were developed. A D-N inhibitor of CREB, termed A-CREB, was constructed by fusing a designed acidic amphipathic extension onto the N terminus of the CREB leucine zipper domain. The acidic extension of A-CREB interacts with the basic region of CREB forming a coiled-coil extension of the leucine zipper and thus prevents the basic region of wild-type CREB from binding to DNA. Other D-N inhibitors generated in a similar manner with the dimerization domains of Fos, Jun, C/EBP, ATF-2, or VBP did not block CREB DNA binding activity, nor did they inhibit transcriptional activation of a minimal promoter containing a single CRE in PC12 cells. A-CREB inhibited activation of CRE-mediated transcription evoked by three distinct stimuli: forskolin, which increases intracellular cAMP; membrane depolarization, which promotes Ca2+ influx; and nerve growth factor (NGF). A-CREB completely inhibited cAMP-mediated, but only partially inhibited Ca2+- and NGF-mediated, transcription of a reporter gene containing 750 bp of the native c-fos promoter. Moreover, glutamate induction of c-fos expression in primary cortical neurons was dependent on CREB. In contrast, induction of c-fos transcription by UV light was not inhibited by A-CREB. Lastly, A-CREB attenuated NGF induction of morphological differentiation in PC12 cells. These results suggest that CREB or its closely related family members are general mediators of stimulus-dependent transcription of c-fos and are required for at least some of the long-term actions of NGF.
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Daaka Y, Luttrell LM, Ahn S, Della Rocca GJ, Ferguson SS, Caron MG, Lefkowitz RJ. Essential role for G protein-coupled receptor endocytosis in the activation of mitogen-activated protein kinase. J Biol Chem 1998; 273:685-8. [PMID: 9422717 DOI: 10.1074/jbc.273.2.685] [Citation(s) in RCA: 436] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The classical paradigm for G protein-coupled receptor (GPCR) signal transduction involves the agonist-dependent interaction of GPCRs with heterotrimeric G proteins at the plasma membrane and the subsequent generation, by membrane-localized effectors, of soluble second messengers or ion currents. Termination of GPCR signals follows G protein-coupled receptor kinase (GRK)- and beta-arrestin-mediated receptor uncoupling and internalization. Here we show that these paradigms are inadequate to account for GPCR-mediated, Ras-dependent activation of the mitogen-activated protein (MAP) kinases Erk1 and -2. In HEK293 cells expressing dominant suppressor mutants of beta-arrestin or dynamin, beta2-adrenergic receptor-mediated activation of MAP kinase is inhibited. The inhibitors of receptor internalization specifically blocked Raf-mediated activation of MEK. Plasma membrane-delimited steps in the GPCR-mediated activation of the MAP kinase pathway, such as tyrosine phosphorylation of Shc and Raf kinase activation by Ras, are unaffected by inhibitors of receptor internalization. Thus, GRKs and beta-arrestins, which uncouple GPCRs and target them for internalization, function as essential elements in the GPCR-mediated MAP kinase signaling cascade.
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365
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Rousseau MF, Massart PE, van Eyll C, Etienne J, Ahn S, Schaefer HG, Mueck W, Bornemann M, Pouleur H. Dose-related hemodynamic and electrocardiographic effects of the calcium promoter BAY y 5959 in the presence or absence of congestive heart failure. J Am Coll Cardiol 1997; 30:1751-7. [PMID: 9385903 DOI: 10.1016/s0735-1097(97)00368-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES The aim of this study was to assess the cardiovascular effects of BAY y 5959, a calcium promoter modulating myocardial calcium channels, in the presence or absence of congestive heart failure. BACKGROUND There is still a clinical need for short-term administration of intravenous positive inotropes. BAY y 5959 was developed as a new approach to increase myocardial performance by selectively enhancing calcium influx in the myocytes. METHODS Forty-one patients (21 without and 20 with congestive heart failure) were studied in an open label, dose-ranging study. Hemodynamic variables (including left ventricular [LV] angiography) and plasma samples were obtained at baseline and after 20 min of intravenous infusion of BAY y 5959 at doses ranging from 0.25 to 4.5 microg/kg body weight per min. RESULTS In both study groups, BAY y 5959 produced dose-dependent increases in the indexes of inotropic state, without affecting isovolumetric relaxation rate. The magnitude of the response was comparable in patients with or without heart failure (average 38% increase in maximal first derivative of LV pressure [dP/dt max] at plasma levels of 100 microg/liter). BAY y 5959 also induced mild but statistically significant bradycardia and significantly decreased end-systolic volume while producing a leftward shift of the pressure-volume loop. Mean aortic pressure was unaffected at doses up to 3.0 microg/kg per min, and cardiac index improved in patients with heart failure at doses of 2.0 microg/kg per min (+23%, p < 0.05). However, at a dose of 4.5 microg/kg per min, mean aortic pressure and LV systolic wall stress increased, suggesting systemic vasoconstriction. The QT interval was also prolonged significantly at most doses. CONCLUSIONS BAY y 5959 exhibits positive inotropic effects in patients with and without heart failure. The optimal response--combining bradycardia, reduced preload and improved cardiac output--appeared to be achieved at a dose of approximately 2.0 microg/kg per min. The impact of QT prolongation with regard to potential antiarrhythmic or proarrhythmic effects is unclear at this time.
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Ahn S, Warren WS, Lee S. Quantum treatment of intermolecular multiple-quantum coherences with intramolecular J coupling in solution NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 1997; 128:114-129. [PMID: 9356265 DOI: 10.1006/jmre.1997.1226] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A recently introduced density matrix picture for dipolar effects in solution NMR (1996, J. Chem. Phys. 105, 874) gave complete solutions for intermolecular multiple-quantum coherences for single-component samples without scalar couplings. This paper, for the first time, shows that this quantum picture can lead to explicit signal expressions for multicomponent samples of molecules with internal scalar couplings (here assumed to generate a first-order spectrum) and long-range dipolar couplings. Experimental observation of a triplet in the indirectly detected dimension for a heteronuclear CRAZED sequence (13CHCl3 sample, ZQ or 2Q coherences) gives clear evidence that the coupling is due to the intermolecular dipolar coupling. We also make comparisons with classical pictures which introduce the dipolar demagnetization field in multicomponent spin systems.
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367
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Rutherford RB, Baker JD, Ernst C, Johnston KW, Porter JM, Ahn S, Jones DN. Recommended standards for reports dealing with lower extremity ischemia: revised version. J Vasc Surg 1997; 26:517-38. [PMID: 9308598 DOI: 10.1016/s0741-5214(97)70045-4] [Citation(s) in RCA: 2477] [Impact Index Per Article: 91.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Recommended standards for analyzing and reporting on lower extremity ischemia were first published by the Journal of Vascular Surgery in 1986 after approval by the Joint Council of The Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery. Many of these standards have been accepted and are used in the current literature on peripheral arterial occlusive disease. With the passage of time, some oversights, aspects that require clarification, and better modifications have been recognized. This report attempts to correct these shortcomings while reinforcing those recommendations that have proven satisfactory. Explanatory comments are added to facilitate understanding and application. This version is intended to replace the original version.
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Dadparvar S, Samimi F, Ahn S, Wang J, Kapadia KM, Gillan MM, Krishna L, Slizofski WJ. CYCLOSPORINE NEPHROTOXICITY AND THE ROLE OF TRIPLE RENAL SCINTIGRAPHY. Clin Nucl Med 1997. [DOI: 10.1097/00003072-199704000-00025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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369
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Youngblut JM, Ahn S. How does maternal employment affect preterm infants? MCN Am J Matern Child Nurs 1997; 22:204-8. [PMID: 9234609 PMCID: PMC3560847 DOI: 10.1097/00005721-199707000-00009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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370
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Abachi S, Abbott B, Abolins M, Acharya BS, Adam I, Adams DL, Adams M, Ahn S, Aihara H, Alitti J, Álvarez G, Alves GA, Amidi E, Amos N, Anderson EW, Aronson SH, Astur R, Avery RE, Baarmand MM, Baden A, Balamurali V, Balderston J, Baldin B, Banerjee S, Bantly J, Bartlett JF, Bazizi K, Bendich J, Beri SB, Bertram I, Bezzubov VA, Bhat PC, Bhatnagar V, Bhattacharjee M, Bischoff A, Biswas N, Blazey G, Blessing S, Bloom P, Boehnlein A, Bojko NI, Borcherding F, Borders J, Boswell C, Brandt A, Brock R, Bross A, Buchholz D, Burtovoi VS, Butler JM, Carvalho W, Casey D, Castilla-Valdez H, Chakraborty D, Chang S, Chekulaev SV, Chen L, Chen W, Choi S, Chopra S, Choudhary BC, Christenson JH, Chung M, Claes D. Isolated Photon Cross Section in the Central and Forward Rapidity Regions in pp-bar Collisions at sqrt s=1.8 TeV. PHYSICAL REVIEW LETTERS 1996; 77:5011-5015. [PMID: 10062692 DOI: 10.1103/physrevlett.77.5011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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371
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Emanuel JR, Damico C, Ahn S, Bautista D, Costa J. Highly sensitive nonradioactive single-strand conformational polymorphism. Detection of Ki-ras mutations. DIAGNOSTIC MOLECULAR PATHOLOGY : THE AMERICAN JOURNAL OF SURGICAL PATHOLOGY, PART B 1996; 5:260-4. [PMID: 8955617 DOI: 10.1097/00019606-199612000-00006] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Mutation detection by single-strand conformational polymorphism (SSCP) analysis is more difficult when the variant is limited to a small proportion of target sequences in a sample. Use of SYBR-Green II, a sensitive, nonradioactive, minimally hazardous nucleic acid stain, permits detection of Ki-ras mutants present as less than 0.5% of the target sequences. The polymerase chain reaction (PCR) primers we have selected produce an amplicon that distinguishes all clinically observed variants in Ki-ras codons 12 and 13 from the wild type. We compared mutant discrimination and SYBR-Green II detection sensitivity in three formats: (a) standard MDE gel SSCP, (b) rapid minigel MDE using an internal gel temperature controller, and (c) rapid resolution in chilled 15% (37.5:1) acrylamide minigels. All these gels are easily evaluated by standard ultraviolet transillumination and digital image analysis. This ssDNA staining method is rapid, highly reproducible, and minimally hazardous, and minigels use 25% the reagents of most other systems. Our improvements are relevant for the detection of mutations in pathologic samples with minimal targets, such as fine-needle aspirates, and body fluids in which mutated alleles of a gene may be present at low levels but carry a high level of diagnostic or prognostic importance.
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Abachi S, Abbott B, Abolins M, Acharya BS, Adam I, Adams DL, Adams M, Ahn S, Aihara H, Alitti J, Álvarez G, Alves GA, Amidi E, Amos N, Anderson EW, Aronson SH, Astur R, Avery RE, Baarmand MM, Baden A, Balamurali V, Balderston J, Baldin B, Banerjee S, Bantly J, Bartlett JF, Bazizi K, Bendich J, Beri SB, Bertram I, Bezzubov VA, Bhat PC, Bhatnagar V, Bhattacharjee M, Bischoff A, Biswas N, Blazey G, Blessing S, Bloom P, Boehnlein A, Bojko NI, Borcherding F, Borders J, Boswell C, Brandt A, Brock R, Bross A, Buchholz D, Burtovoi VS, Butler JM, Carvalho W, Casey D, Castilla-Valdez H, Chakraborty D, Chang S, Chekulaev SV, Chen L, Chen W, Choi S, Chopra S, Choudhary BC, Christenson JH, Chung M, Claes D. Search for Anomalous WW and WZ Production in pp-bar Collisions at sqrt s=1.8 TeV. PHYSICAL REVIEW LETTERS 1996; 77:3303-3308. [PMID: 10062187 DOI: 10.1103/physrevlett.77.3303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Abachi S, Abbott B, Abolins M, Acharya BS, Adam I, Adams DL, Adams M, Ahn S, Aihara H, Alitti J, Álvarez G, Alves GA, Amidi E, Amos N, Anderson EW, Aronson SH, Astur R, Avery RE, Baarmand MM, Baden A, Balamurali V, Balderston J, Baldin B, Banerjee S, Bantly J, Bartlett JF, Bazizi K, Belyaev A, Bendich J, Beri SB, Bertram I, Bezzubov VA, Bhat PC, Bhatnagar V, Bhattacharjee M, Bischoff A, Biswas N, Blazey G, Blessing S, Bloom P, Boehnlein A, Bojko NI, Borcherding F, Borders J, Boswell C, Brandt A, Brock R, Bross A, Buchholz D, Burtovoi VS, Butler JM, Carvalho W, Casey D, Castilla-Valdez H, Chakraborty D, Chang S, Chekulaev SV, Chen L, Chen W, Choi S, Chopra S, Choudhary BC, Christenson JH, Chung M. Measurement of the W Boson Mass. PHYSICAL REVIEW LETTERS 1996; 77:3309-3314. [PMID: 10062188 DOI: 10.1103/physrevlett.77.3309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Rousseau MF, Hayashida W, van Eyll C, Hess OM, Benedict CR, Ahn S, Chapelle F, Kobrin I, Pouleur H. Hemodynamic and cardiac effects of the selective T-type and L-type calcium channel blocking agent mibefradil in patients with varying degrees of left ventricular systolic dysfunction. J Am Coll Cardiol 1996; 28:972-9. [PMID: 8837576 DOI: 10.1016/s0735-1097(96)00261-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES This study sought to assess the hemodynamic and cardiac effects of two dose levels of mibefradil in patients with varying degrees of ischemic left ventricular dysfunction. BACKGROUND Mibefradil is a new, selective T-type and L-type calcium channel blocking agent. Because L-type channel blockade may depress myocardial performance, an invasive hemodynamic study was performed to assess the safety of this agent. METHODS We performed an open label study, examining the effects of two intravenous doses of mibefradil, selected to produce plasma levels comparable to those measured after oral administration of 50 mg (dose 1: 400 ng/ml) or 100 mg (dose 2: 800 ng/ml) of the drug. Variables studied included the indexes of left ventricular function and neurohormone levels. Patients were stratified according to ejection fraction (EF) (> or = 40%, n = 26; < 40%, n = 24) and the presence (n = 15) or absence (n = 35) of heart failure. RESULTS In patients with preserved systolic function, dose 1 had no clinically significant hemodynamic effects, but dose 2 decreased mean aortic pressure and systemic vascular resistance (-8.5 mm Hg, -12%, both p < 0.01) and also reduced end-systolic stress and volume, thus improving EF (52% to 58%, p < 0.01). Heart rate tended to decrease. In patients with depressed EF, heart rate decreased significantly with both doses. The effects of dose 1 mimicked those observed after dose 2 in patients with preserved EF. Dose 2 (plasma levels 1,052 +/- 284 ng/ml) still decreased left ventricular systolic wall stress and improved EF (24.0% to 28.5%, p < 0.05) but also significantly depressed the maximal first derivative of left ventricular pressure. Examination of individual pressure-volume loops in two patients with heart failure showed a clear rightward shift of the loop despite a decrease in systolic pressure, suggesting negative inotropy. Neurohormone levels were unchanged at both dose levels and in all subgroups. CONCLUSIONS Intravenous mibefradil was well tolerated and produced an overall favorable cardiovascular response. However, high plasma concentrations might produce myocardial depression in patients with heart failure, and caution should be exerted in this setting.
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Abachi S, Abbott B, Abolins M, Acharya BS, Adam I, Adams DL, Adams M, Ahn S, Aihara H, Alitti J, Álvarez G, Alves GA, Amidi E, Amos N, Anderson EW, Aronson SH, Astur R, Avery RE, Baarmand MM, Baden A, Balamurali V, Balderston J, Baldin B, Banerjee S, Bantly J, Bartlett JF, Bazizi K, Bendich J, Beri SB, Bertram I, Bezzubov VA, Bhat PC, Bhatnagar V, Bhattacharjee M, Bischoff A, Biswas N, Blazey G, Blessing S, Bloom P, Boehnlein A, Bojko NI, Borcherding F, Borders J, Boswell C, Brandt A, Brock R, Bross A, Buchholz D, Burtovoi VS, Butler JM, Carvalho W, Casey D, Castilla-Valdez H, Chakraborty D, Chang S, Chekulaev SV, Chen L, Chen W, Choi S, Chopra S, Choudhary BC, Christenson JH, Chung M, Claes D. Azimuthal Decorrelation of Jets Widely Separated in Rapidity. PHYSICAL REVIEW LETTERS 1996; 77:595-600. [PMID: 10062854 DOI: 10.1103/physrevlett.77.595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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