1051
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Lahav N, Chang S. The possible role of solid surface area in condensation reactions during chemical evolution: reevaluation. J Mol Evol 1976; 8:357-80. [PMID: 13225 DOI: 10.1007/bf01739261] [Citation(s) in RCA: 150] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Published data on adsorption and condensation of amino acids, purine and pyrimidine bases, sugars, nucleosides, and nucleotides are analyzed in connection with Bernal's hypothesis that clays and other minerals may have provided the most likely surface for adsorption and condensation of these molecules in prebiotic times. Using surface concentration and reaction rate as the main criteria for the feasibility of condensation reactions, four types of prebiotic environments were analyzed: (1) an ocean-sediment system, (2) a dehydrated lagoon bed produced by evaporation, (3) the surface of a frozen sediment, and (4) a fluctuating system where hydration (rainstorms, tidal variations, flooding) and dehysration (evaporation) take place in a cyclic manner. With the possible exception of nucleotides, low adsorption of organomonomers on sediment surfaces of a prebiotic ocean (pH 8) is expected, and significant condensation is considered unlikely. In dehydrated and frozen systems, high surface concentrations are probable and condensation is more likely. In fluctuating environments, condensation rates will be enhanced and the size distribution of the oligomers formed during dehydration may be influenced by a "redistribution mechanism" in which adsorbed oligomers and monomers are desorbed and redistributed on the solid surface during the next hydration-dehydration cycle.
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1052
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Chang S, Dusanic DG. In vitro phagocytosis of Trypanosoma musculi by mouse macrophage. ZHONGHUA MINGUO WEI SHENG WU XUE ZA ZHI = CHINESE JOURNAL OF MICROBIOLOGY 1976; 9:73-82. [PMID: 1037536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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1053
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1054
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Ng H, Chang S, Ho S. Dystocia due to fetal ascites. MODERN MEDICINE OF ASIA 1976; 12:10. [PMID: 1012260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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1055
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1056
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Abramson DH, Chang S, Coleman J. Pilocarpine therapy in glaucoma: effects on anterior chamber depth and lens thickness in patients receiving long-term therapy. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 1976; 94:914-8. [PMID: 820317 DOI: 10.1001/archopht.1976.03910030454002] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The effect of pilocarpine hydrochloride on the anterior chamber depth and lens thickness was measured in 20 eyes of patients with chronic open-angle glucoma who were receiving long-term glaucoma therapy with pilocarpine. Measurements were made with high-resolution ultrasonic biometry. This study demonstrated that regardless of their age (58.4 years, average) and the fact that they had been regularly using pilocarpine from two to four times a day, 85% of these patients demonstrated narrowing of the anterior chamber (AC) depth (average, 0.19 mm) and thickening of the lens (average, 0.21 mm) with each instillation of pilocarpine. In approximately 15% of eyes, a repeatable deepening of the AC depth and flattening of the lens was noted.
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1057
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Estevez CM, Dillon JC, Walker PD, Feigenbaum H, Chang S. Echocardiographic manifestations of aortic cusp rupture in a myxomatous aortic valve. Chest 1976; 69:685-7. [PMID: 1269282 DOI: 10.1378/chest.69.5.685] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A 16-year-old pregnant black girl who had spontaneous perforation of the aortic valve associated with myxomatous aortic valvular degeneration is presented. The echocardiogram revealed chaotic systolic motion of one of the aortic cusps, diastolic aortic valvular fluttering, and abnormal diastolic echoes in the left ventricular outflow tract. The report illustrates that the echocardiographic features associated with valvular vegetations are not specific for infectious endocarditis.
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1058
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Dillon JC, Feigenbaum H, Weyman AE, Corya BC, Peskoe S, Chang S. M-mode echocardiography in the evaluation of patients for aneurysmectomy. Circulation 1976; 53:657-62. [PMID: 1253386 DOI: 10.1161/01.cir.53.4.657] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In order to determine whether echocardiography could be useful in predicting surgical mortality of aneurysmectomy, preoperative condensed M-mode echocardiographic scans were taken from both mid (standard position) and low (nearer apex) intercostal spaces and/or from the subxiphoid area in eighteen patients who were sent to surgery for aneurysmectomy. Eleven of the eighteen patients survived aneurysmectomy. All eleven had mid left ventricular dimensions less than 3.3 cm/m2 and low dimensions of 3.8 cm/m2 or less. Of the seven patients who died, the mid and low left ventricular dimensions exceeded 3.3 cm/m2 and 3.8 cm/m2, respectively, with one exception. The combination of abnormal mitral valve closure, a dilated mid dimension and lack of normal motion in opposing wall segments was only seen in six nonsurvivors. Echocardiography can provide information concerning the state of the left ventricle in patients with ventricular aneurysms and these findings may be helpful in predicting surgical mortality for aneurysmectomy.
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1059
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Feigenbaum H, Corya BC, Dillon JC, Weyman AE, Rasmussen S, Black MJ, Chang S. Role of echocardiography in patients with coronary artery disease. Am J Cardiol 1976; 37:775-86. [PMID: 1266745 DOI: 10.1016/0002-9149(76)90375-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Impaired left ventricular performance, one of the hallmarks of coronary artery disease, can be detected by echocardiography in various ways. One of these approaches is the recording of abnormal wall motion. Because of the way in which the left ventricle can be examined echocardiographically, this technique has the capability of detecting regional wall abnormalities. In fact echocardiography is probably the most sensitive technique available, including even contrast ventriculography, for the detection of akinetic, hypokinetic or dyskinetic wall segments. With increasing experience it is apparent that more areas of the left ventricle can be examined echocardiographically than had previously been thought possible. Newer techniques include directing the ultrasonic beam not only through the body of the left ventricle but also toward the apical portion of the ventricle near the vicinity of the papillary muscles. In addition the true anterior left ventricular wall can be examined by moving the transducer laterally away from the left sternal border. Yet another approach utilizes a subxiphoid position for the transducer while the ultrasonic beam is directed through the medial portion of the septum and posterolateral wall of the left ventricle. M-mode scanning techniques together with recently developed cross-sectional echocardiographic instruments give great promise of improved detection of abnormalities of ventricular shape, especially the presence of aneurysms. The cross-sectional approach makes it possible to examine the left ventricular apex, an area virtually impossible to record with M-mode echocardiography. Recording of left ventricular dimensions and abnormal mitral valve motion may help in assessing overall left ventricular performance. A dilated left ventricular dimension in the vicinity of the mitral valve seems to be an ominous finding both in patients with acute myocardial infarction and in patients with chronic coronary disease being considered for possible surgery. Another echocardiographic sign of abnormal ventricular performance is altered closure of the mitral valve, which reflects a significantly elevated left ventricular diastolic pressure. These echocardiographic techniques are still in the investigational stages and are more technically difficult than the usual echocardiographic applications. However, the preliminary data are encouraging and make us hopeful that echocardiography will prove to be an important tool in the overall evaluation of the left ventricle in patients with coronary artery disease.
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1060
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Weyman AE, Feigenbaum H, Hurwitz RA, Girod DA, Dillon JC, Chang S. Cross-sectional echocardiography in evaluating patients with discrete subaortic stenosis. Am J Cardiol 1976; 37:358-65. [PMID: 943922 DOI: 10.1016/0002-9149(76)90284-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Ten patients with discrete subvalvular aortic stenosis were examined using a real time, high resolution cross-sectional echocardiographic scanner. There were two patients (Group I) with a thin discrete subvalvular membrane, five (Group II) with a more extensive area of subvalvular narrowing and three with a residual area of outflow tract obstruction after surgical revision (Group III). In patients with a thin obstructing membrane (Group I), two distinct linear echoes were observed in the outflow tract. These echoes were not continuous with the walls of the outflow tract and showed some dynamic motion during the cardiac cycle. In four of the five patients with diffuse outflow tract narrowing (Group II), a relatively extensive area of inward bowing of both the anterior and posterior margins of the outflow tract was noted. In the fifth case, there was a prominent localized shelf-like increase in thickness of the basal portion of the muscular septum with a corresponding echo projecting anteriorly from the mid-portion of the anterior or mitral leaflet. The three cases examined after surgical revision of the outflow tract (Group III), had different patterns of outflow tract narrowing, but narrowing was clearly demonstrated. This study suggests that cross-sectional echocardiography offers an alternative and probably improved method for the noninvasive visualization of the left ventricular outflow tract.
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1061
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Hampar B, Lenoir G, Nonoyama M, Derger JG, Chang S. Cell cycle dependence for activation of Epstein-Barr virus by inhibitors of protein synthesis or medium deficient in arginine. Virology 1976; 69:660-8. [PMID: 176789 DOI: 10.1016/0042-6822(76)90494-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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1062
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Biggs JT, Holland WH, Chang S, Hipps PP, Sherman WR. Electron beam ionization mass fragmentographic analysis of tricyclic antidepressants in human plasma. J Pharm Sci 1976; 65:261-8. [PMID: 1255460 DOI: 10.1002/jps.2600650221] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A method for the measurement, in human plasma, of all tertiary and secondary tricyclic antidepressants prescribed in the United States is described. The method uses electron beam ionization GLC-mass spectrometry, employing a computer-controlled multiple-ion detector. This method, mass fragmentography, is used with internal standards for each drug. Plasma levels to as low as 10 ng/ml of the following drugs can be measured: amitriptyline, nortriptyline, doxepin, desmethyldoxepin, imipramine, desipramine, and protriptyline. Deuterium-labeled amitriptyline and imipramine are used as internal standards for those two drugs; for the other drugs, deuterated amitriptyline, nortriptyline, desmethyldoxepin, or desipramine is used. The method can measure up to 15 samples/hr, making it practical for large-scale studies of these drugs in patients. Spectra of each drug and examples of their analysis are given.
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1063
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Weyman AE, Feigenbaum H, Hurwitz RA, Girod DA, Dillon JC, Chang S. Localization of left ventricular outflow obstruction by cross-sectional echocardiography. Am J Med 1976; 60:33-8. [PMID: 943141 DOI: 10.1016/0002-9343(76)90530-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cross-sectional echocardiographic studies were performed using a high resolution real time mechanical sector scanner in 70 patients with left ventricular outflow obstruction. Seven separate obstructive patterns were recorded in these patients. An area of aortic narrowing just distal to the aortic valve at the superior border of the left atrium was noted with supravalvular aortic stenosis. With congenital valvular aortic stenosis there was an increase in echo production by the thickened aortic leaflets. During systole these prominent leaflet echoes curved inward toward the center of the aortic root reflecting the systolic doming of the valve. With calcific aortic stenosis, the calcification produced an area of dense linear echoes attached in varying degrees to either the anterior or posterior border of the aortic root. At the subvalvular level three obstructive patterns were recorded; with a discrete subvalvular obstructive membrane two linear echoes apparently produced by the inner margins of the obstructing membrane were recorded in the outflow tract. With more extensive fibromuscular narrowing of the subvalvular area, there was inward bowing of the echoes from both the anterior and posterior walls of the outflow tract. In one case this was a dense shelf-like mass of echoes extending downward from the basal portion of the interventricular septum toward the mid-portion of the anterior mitral leaflet with corresponding systolic anterior motion of the mitral leaflet. In patients with idiopathic hypertrophic subaortic stenosis there was systolic anterior motion of the anterior mitral leaflet beginning just distal to the point of coaptation of the mitral leaflets and extending distally toward the papillary muscles. This report suggests that the enlarged field of vision and spatial orientation provided by the cross-sectional echocardiographic technic should improve our ability to record and characterize areas of obstruction to left ventricular outflow.
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1064
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Abstract
Four cases are presented to illustrate the echo patterns of pulmonary valve motion in patients with pulmonary regurgitation caused by pulmonary hypertension, idiopathic dilatation of the pulmonary artery, or congenital absence of the pulmonary valve or in association with pulmonary stenosis. Absence of the pulmonary 'a' wave, fluttering of the e-f slope, and midsystolic closure or 'notching' of the valve were noted with pulmonary hypertension. In the case with idiopathic dilatation of the pulmonary artery a normal echo pattern of pulmonary valve motion along with distinct dilatation of the pulmonary artery at the valvular level were present. Pronounced dilatation and systolic expansion of the pulmonary artery along with dilatation of the right ventricle were seen with congenital absence of the pulmonary valve. No pulmonary valve could be demonstrated on multiple scans from the right ventricle to pulmonary artery. In Case 4 large 'a' waves (14 mm) were noted, indicating a reversal of the normal end-diastolic gradient across the valve and suggesting that pulmonary regurgitation in this case was associated with right ventricular outflow obstruction. Study of the echo pattern of pulmonary valve motion may therefore provide useful information in establishing the cause of pulmonary regurgitation.
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1065
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Weyman AE, Feigebaum H, Dillon JC, Chang S. Cross-sectional echocardiography in assessing the severity of valvular aortic stenosis. Circulation 1975; 52:828-34. [PMID: 1175263 DOI: 10.1161/01.cir.52.5.828] [Citation(s) in RCA: 89] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Real-time, cross-sectional echocardiograms were recorded in 28 consecutive adult patients with valvular aortic stenosis using a high resolution, mechanical sector scanner. Using the cross-sectional technique, the aortic valve orifice diameter was recorded in each of the 28 patients. With M-mode echocardiographic examination of these same patients, this value could be estimated in only 21 of these 28 patients (75%). The maximum aortic valve diameter recorded during the cross-sectional study averaged 7.9 +/- 1.8 mm (range 4-11 mm) in 15 patients with severe aortic stenosis; 11.6 +/- 2.3 mm (range 9-15 mm) in five patients with moderate aortic stenosis; 16.9 +/- 2.0 mm (range 14-20 mm) in eight patients with mild aortic stenosis; and 20.5 +/- 2.8 mm (range 15-26 mm) in 25 patients with no evidence of aortic valve disease. Comparing the means of these groups yielded the following: severe vs moderate P less than 0.005; moderate vs mild P less than 0.001; and mild vs normal P less than 0.001. Although there was some overlap between the individual groups, a clear separation existed between patients with severe and mild aortic stenosis. In addition, the group of patients in whom surgical intervention was recommended was also separated from the other subjects. When the aortic valve orifice was recorded using the M-mode technique, there was also a good correlation with the severity of the stenosis; however, the tendency of the M-mode study to overestimate severity in individual patients with calcific aortic stenosis and to underestimate severity in congenital aortic stenosis was again demonstrated. This study suggests that real-time, high resolution, cross-sectional echocardiography should be valuable in the noninvasive assessment of patients with aortic stenosis.
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1066
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Edwards DJ, Chang S. Evidence for interacting catalytic sites of human platelet monoamine oxidase. Biochem Biophys Res Commun 1975; 65:1018-25. [PMID: 1156412 DOI: 10.1016/s0006-291x(75)80487-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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1067
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1068
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Chang S, Carbon J. The nucleotide sequence of a precursor to the glycine- and threonine-specific transfer ribonucleic acids of Escherichia coli. J Biol Chem 1975; 250:5542-55. [PMID: 167017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The primary nucleotide sequence of an Escherichia coli tRNA precursor molecule has been determined. This precursor RNA, specified by the transducing phage lambdah80dglyTsuA36 thrT tyrT, accumulates in a mutant strain temperature-sensitive for RNase P activity. The 170-nucleotide precursor RNA is processed by E. coli extracts to form mature tRNA Gly 2 suA36 and tRNA Thr ACU/C. The sequence of the precursor is pG-U-U-C-C-A-G-G-A-U-G-C-G-G-G-C-A-U-C-G-U-A-U-A-A-U-G-G-C-U-A-U-U-A-C-C-U-C-A-G-C-C-U-N-C-U-A-A-G-C-U-G-A-U-G-A-U-G-C-G-G-G-T-psi-C-G-A-U-U-C-C-C-G-C-U-G-C-C-C-G-C-U-C-C-A-A-G-A-U-G-U-G-C-U-G-A-U-A-U-A-G-C-U-C-A-G-D-D-G-G-D-A-G-A-G-C-G-C-A-C-C-C-U-U-G-G-U-mt6A-A-G-G-G-U-G-A-G-m7G-U-C-G-G-C-A-G-T-psi-C-G-A-A-U-C-U-G-C-C-U-A-U-C-A-G-C-A-C-C-A-C-U-UOH(tRNA sequences are italicized). It contains the entire primary nucleotide sequences of tRNA Gly2 suA36 and tRNA Thr ACU/C, including the common 3'-terminal sequence, CCA. Nineteen additional nucleotides are present, with 10 at the 5' end, 3 at the 3' end, and the remaining 6 in the inter-tRNA spacer region. RNase P cleaves the precursor specifically at the 5' ends of the mature tRNA sequences.
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1069
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Loew GH, Chang S, Berkowitz D. Quantum chemical study of relative reactivities of a series of amines and nitriles: relevance to prebiotic chemistry. J Mol Evol 1975; 5:131-52. [PMID: 169357 DOI: 10.1007/bf01732518] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Using the Iterative Extended Hucken Theory (IEHT) calculations of the elctron distribution and orbital energies of a series of thirteen amines, nitriles and amino-nitriles relevant to prebiotic and cosmo-chemistry have been carried out. Ground state properties such as the energy and nature of the highest occupied (HOMO) and lowest empty (LEMO) molecular orbitals, net atomic charges and number of non-bonding electrons have been identified as criteria for correlating the relative nucleophilicity of amine and nitrile nitrogens and the electrophilicity of nitrile and other unsaturated carbon atoms. The results of such correlations can be partially verified by known chemical behavior of these compounds and are used to predict and understand their role in prebiotic organic synthesis.
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1070
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Chang S, Carbon J. The nucleotide sequence of a precursor to the glycine- and threonine-specific transfer ribonucleic acids of Escherichia coli. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)41215-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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1071
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Chang S, Feigenbaum H, Dillion J. Condensed M-mode echocardiograhpic scan of the symmetrical left ventricle. Chest 1975; 68:93-5. [PMID: 1149538 DOI: 10.1378/chest.68.1.93] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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1072
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Weyman AE, Dillon JC, Feigenbaum H, Chang S. Echocardiographic differentiation of infundibular from valvular pulmonary stenosis. Am J Cardiol 1975; 36:21-6. [PMID: 125035 DOI: 10.1016/0002-9149(75)90862-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Echocardiographic tracings of the pulmonary valve were examined in 24 normal subjects, 16 patients with valvular pulmonary stenosis and 3 patients with infundibular pulmonary stenosis. In normal subjects, atrial contraction produced a slight posterior opening motion of the pulmonary valve leaflet (a wave). This presystolic opening motion (a wave) varied with respiration, and maximal a wave depth recorded during quiet inspiration (Amax) averaged 3.7 plus or minus 1.2 (standard error of the mean) mm (range 2 to 7 mm). In the 10 cases with moderate or severe valvular pulmonary stenosis, increased force of right atrial contraction and elevated right ventricular end-diastolic pressure resulted in an increased posterior or opening motion of the pulmonary valve leaflet, and Amax averaged 9.6 plus or minus 2.0 mm (range 8 to 13 mm, P less than 0.001 versus normal). When both anterior and posterior leaflets were recorded, presystolic opening or doming of the valve was observed. In six cases of mild valvular pulmonary stenosis, Amax averaged 4 plus or minus 2.5 mm (not significant). In patients with infundibular pulmonary stenosis, marked chaotic systolic fluttering of the valve leaflet, which lies in the turbulent stream of blood distal to the obstruction, was recorded. This finding was never seen with valvular pulmonary stenosis. In two cases of mild infundibular pulmonary stenosis, the amplitude of presystolic opening motion was within the normal range of 3 and 7 mm. In one case of severe infundibular pulmonary stenosis, no presystolic opening motion was recorded, thus suggesting that the small pressure changes produced by atrial systole failed to reach the valve leaflets. Echocardiography, therefore, should be of use in differentiating valvular from infundibular pulmonary stenosis.
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1073
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Carbon J, Chang S, Kirk LL. Clustered tRNA genes in Escherichia coli: transcription and processing. BROOKHAVEN SYMPOSIA IN BIOLOGY 1975:26-36. [PMID: 1104094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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1074
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Sonozaki H, Seki H, Chang S, Okuyama M, Juji T. Human lymphocyte antigen, HL-A27, in Japanese patients with ankylosing spondylitis. TISSUE ANTIGENS 1975; 5:131-6. [PMID: 1129750 DOI: 10.1111/j.1399-0039.1975.tb00541.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A high association of HL-A27 specificity with ankylosing spondylitis was found in Japanese patients in spite of a very low frequency of this specificity in a normal Japanese population. These findings coincide well with those in Caucasian patients, and indicate the strong relationship between the susceptibility to ankylosing spondylitis and HL-A27 specificity beyond racial differences. No particular HL-A patterns were noted in patients with the ossification of the posterior longitudinal ligament of the cervical vertebrae. This observation provides an evidence that this disease is etiologically different from ankylosing spondylitis.
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1075
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Weyman AE, Dillon JC, Feigenbaum H, Chang S. Premature pulmonic valve opening following sinus of Valsalva aneurysm rupture into the right atrium. Circulation 1975; 51:556-60. [PMID: 1139764 DOI: 10.1161/01.cir.51.3.556] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Echocardiographic features of a patient with sinus of Valsalva aneurysm rupture into the right atrium are described. The aneurysm presented as a dense echo-producing mass in the right atrium which descended into the tricuspid orifice during diastole and withdrew back into the atrium during ventricular systole. Pulmonic valve exho motion demonstrated early diastolic pulmonic valve opening indicating an early right ventricular diastolic pressure rise exceeding simultaneous pulmonary artery pressure. Since the aorta is the only source of early diastolic pressure in excess of pulmonary artery pressure available to the right heart, this finding of early diastolic pulmonic valve opening indicated the presence of a fistula between the aorta and right heart. Other interesting echocardiographic features of this case are also presented.
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1076
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Loew GH, Chang S. Quantum chemical study of the thermodynamics, kinetics of formation and bonding of H2CN: relevance to prebiotic chemistry. ORIGINS OF LIFE 1975; 6:117-25. [PMID: 168533 DOI: 10.1007/bf01372396] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Using the Iterative Extended Huckel Theory (IEHT), energy-conformation studies have been carried out for H2CN (I), trans-HCNH (IIA), and cis-HCNH (IIB), three possible isomers formed by addition of a hydrogen atom to hydrogen cyanide. Calculations show that the order of decreasing thermodynamic stability is I greater than IIA greater than IIB. Additionally, from calculated energies along simulated reaction pathways, the formation of I from HCN+H appears to be kinetically favored over IIA. Calculated properties of the minimum energy conformers of I and IIA are described and the potential role of H2CN (I) as a reactive intermediate in prebiotic organic synthesis and its possible relevance to interstellar organic chemistry are discussed.
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1077
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Tseng SS, Chang S. Photochemical synthesis of simple organic free radicals on simulated planteary surfaces-an ESR study. ORIGINS OF LIFE 1975; 6:61-73. [PMID: 168539 DOI: 10.1007/978-94-010-2282-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Electron spin resonance spectroscopy provided evidence for formation of hydroxyl radicals during ultraviolet photolysis (254 nm) at -170C of H2O adsorbed on silica gel or of silica gel alone. The carboxyl radical was observed when CO or CO2 or a mixture of CO and CO2 absorbed on silica gel at -170C was irradiated. The ESR signals of these radicals slowly disappeared when the irradiated samples were warmed to room temperature. However, re-irradiation of CO or CO2, or the mixture CO and CO2 on silica gel at room temperature then produced a new species, the carbon dioxide anion radical, which slowly decayed and which was identical with that produced by direct photolysis of formic acid adsorbed on silica gel. The primary photochemical process may involve formation of hydrogen and hydroxyl radicals by means of (1) photodissociation of H2O physically adsorbed on the silica gel, or (2) absorption of the excitation energy by the silica gel surface with subsequent cleavage of the silanol bonds, or (3) dissociation of H2O molecules throug photosensitization by the surfaces or a combination of (1) to (3). Subsequent reactions of these radicals with adsorbed CO or CO2 or both yield carboxyl radicals, CO2H, the precsursors of formic acid. Our results confirm the formation of formic acid under simulated Martian conditions and provide a mechanistic basis for gauging the potential importance of gas-solid photochemistry for chemical evolution on other extraterrestrial bodies, on the primitive earth and on dust grains in the interstellar medium.
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1078
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Abramson DH, Chang S, Coleman DJ, Smith ME. Pilocarpine-induced lens changes. An ultrasonic biometric evaluation of dose response. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 1974; 92:464-9. [PMID: 4433267 DOI: 10.1001/archopht.1974.01010010478003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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1079
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Weyman AE, Dillon JC, Feigenbaum H, Chang S. Echocardiographic patterns of pulmonic valve motion with pulmonary hypertension. Circulation 1974; 50:905-10. [PMID: 4430093 DOI: 10.1161/01.cir.50.5.905] [Citation(s) in RCA: 136] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Echocardiographic tracings of the pulmonic valve were examined in two groups of patients. The first group contained 24 normal patients. The second group consisted of 32 patients with pulmonary hypertension (mean pulmonary artery pressure ≥20 mm Hg). Parameters considered included presence or absence and depth of the "a" wave, amplitude of valve opening (b-c separation), diastolic (e-f) slope, and presence or absence of mid-systolic closure or fluttering of the pulmonic leaflet. An "a" wave was present in all 24 normal subjects. The "a" wave varied with respiration and the maximum "a" wave depth (A Max) averaged 3.7 ± 1.2 mm (mean ±
sd
, range 2-7 mm). A Max was ≥2 mm in all 24 normal patients. In 19 of 24 patients with pulmonary hypertension and sinus rhythm no "a" wave was present. In the other five patients small "a" waves (≤2 mm) occurred. In four of these five patients, right heart failure was present. The diastolic (e-f) slope averaged 36.9 ± 25.4 mm/sec (range 6-115 mm/sec) in normals. With pulmonary hypertension, this slope was significantly less than normal (average 5.2 ± 8.9 mm/sec, range –9 to +30 mm/sec,
P
< .001). In six patients with pulmonary hypertension a negative e-f slope was seen; this never occurred in normals. Mid-systolic closure or notching of the systolic (c-d) segment occurred in 18 of 20 subjects with pulmonary hypertension in whom the leaflet was clearly recorded in mid-systole. This finding was not observed in normals. Likewise, mid-systolic fluttering was present in 22 of 24 patients with pulmonary hypertension. There was no difference in amplitude of leaflet opening between the two groups.
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1080
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Chang S, Silvis SE. Fatty liver produced by hyperalimentation of rats. Am J Gastroenterol 1974; 62:410-8. [PMID: 4216263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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1081
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Weyman AE, Dillon JC, Feigenbaum H, Chang S. Echocardiographic patterns of pulmonary valve motion in valvular pulmonary stenosis. Am J Cardiol 1974; 34:644-51. [PMID: 4418271 DOI: 10.1016/0002-9149(74)90151-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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1082
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Loew GH, Chang S. Quantum chemical study of the thermodynamics, kinetics of formation and bonding of H2CN: relevance to prebiotic chemistry. J Mol Evol 1974; 3:209-24. [PMID: 4369101 DOI: 10.1007/bf01797454] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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1083
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Abstract
Seventeen patients with left bundle branch block were studied using standard echocardiographic techniques employing a strip chart recorder. All 17 patients were found to have specific echocardiographic findings of abnormal septal motion uniquely different from previously described forms found in volume overload states of the right ventricle as well as coronary artery disease. The specific echocardiographic abnormality demonstrated in left bundle branch block is a very dynamic posterior motion of the interventricular septum occurring within 0.04 seconds of the onset of the QRS and preceding the anterior motion of the posterior left ventricular wall during ventricular ejection. This type of septal motion is not seen in the other forms of abnormal septal motion and appears to be specific for left bundle branch block.
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1084
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Rothbaum DA, Dillon JC, Chang S, Feigenbaum H. Echocardiographic manifestation of right sinus of Valsalva aneurysm. Circulation 1974; 49:768-71. [PMID: 4817714 DOI: 10.1161/01.cir.49.4.768] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
This case report describes the distinctive echocardiographic pattern in a patient with a congenital right sinus of Valsalva aneurysm. The echocardiogram demonstrated an abnormal structure extending from the aortic root into the left ventricular chamber adjacent to the interventricular septum. The structure showed diastolic motion away from the septum and systolic motion toward the septum. This movement was consistent with cineangiographic filling of the aneurysm during diastole and emptying during systole. After operative closure of the aneurysm, the echocardiogram showed dense thickening along the aortic root and contiguous interventricular septum, probably representing thrombosis and fibrosis within the obliterated aneurysmal sac; but no abnormal movement of the structure was present.
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1085
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Davis RH, Feigenbaum H, Chang S, Konecke LL, Dillon JC. Echocardiographic manifestations of discrete subaortic stenosis. Am J Cardiol 1974; 33:277-80. [PMID: 4855651 DOI: 10.1016/0002-9149(74)90289-6] [Citation(s) in RCA: 84] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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1086
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Chang S, Hildebrandt W, Silvis SE. The accidental discovery that sodium diatrizoate (Hypaque) infusion will visualize amebic abscesses on hepatic tomograms. Am J Trop Med Hyg 1974; 23:31-4. [PMID: 4810307 DOI: 10.4269/ajtmh.1974.23.31] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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1087
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Dillon JC, Feigenbaum H, Konecke LL, Davis RH, Chang S. Echocardiographic manifestations of valvular vegetations. Am Heart J 1973; 86:698-704. [PMID: 4743337 DOI: 10.1016/0002-8703(73)90350-5] [Citation(s) in RCA: 250] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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1088
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Dillon JC, Feigenbaum H, Konecke LL, Keutel J, Hurwitz RA, Davis RH, Chang S. Echocardiographic manifestations of d-transposition of the great vessels. Am J Cardiol 1973; 32:74-8. [PMID: 4713113 DOI: 10.1016/s0002-9149(73)80087-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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1089
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Konecke LL, Feigenbaum H, Chang S, Corya BC, Fischer JC. Abnormal mitral valve motion in patients with elevated left ventricular diastolic pressures. Circulation 1973; 47:989-96. [PMID: 4705588 DOI: 10.1161/01.cir.47.5.989] [Citation(s) in RCA: 88] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In order to see whether or not the echocardiographically recorded mitral valve could reflect alterations in left ventricular pressure, simultaneous mitral valve echograms and left ventricular pressures were obtained on patients undergoing diagnostic cardiac catheterization. Attention was given to the left ventricular initial diastolic pressure (LVIDP), left ventricular end-diastolic pressure (LVEDP), and the atrial component of the left ventricular pressure (LV
a
). The echocardiographic measurements included the opening velocity of the mitral valve in early diastole (D-E slope) and the interval between the A point, which is the onset of closure of the mitral valve following atrial systole, and the C point, which represents closure of the mitral valve as indicated by the meeting of the anterior and posterior mitral leaflets. In order to compensate for variations in atrioventricular conduction, the A-C interval was subtracted from the electrocardiographic P-R interval. In 19 patients, the LVIDP was less than 14 mm Hg, the LVEDP was less than 20 mm Hg, and the LV
a
was less than 8 mm Hg. In these patients, the D-E slope was greater than 25 cm/sec and the PR-AC interval was greater than 0.06 sec. Six patients who had an LVIDP of 14 mm Hg or greater had a D-E slope of less than 25 cm/sec. There were 14 patients with an LVEDP greater than 20 mm Hg and an LV
a
of 8 mm Hg or greater. All of these patients had a PR-AC interval of less than 0.06 sec. There were an additional three patients who had an LVEDP above 20 mm Hg, but whose LV
a
was less than 8 mm Hg. In these three patients, the PR-AC interval was greater than 0.06 sec. Thus, the shortened PR-AC interval correlated primarily with an elevated LV
a
. This study indicates that the echocardiographic pattern of mitral valve motion is altered in patients who have markedly elevated left ventricular diastolic pressures.
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1090
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Hamabata A, Chang S, Von Hippel PH. Model studies on the effects of neutral salts on the conformational stability of biological macromolecules. IV. Properties of fatty acid amide micelles. Biochemistry 1973; 12:1278-82. [PMID: 4348831 DOI: 10.1021/bi00731a006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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1091
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Hamabata A, Chang S, Von Hippel PH. Model studies on the effects of neutral salts on the conformational stability of biological macromolecules. 3. Solubility of fatty acid amides in ionic solutions. Biochemistry 1973; 12:1271-8. [PMID: 4348830 DOI: 10.1021/bi00731a005] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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1092
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Wong YP, Kearns DR, Shulman RG, Yamane T, Chang S, Chirikjian JG, Fresco JR. High resolution nuclear magnetic resonance study of base pairing in the native and denaturated conformers of transfer RNA Leu 3 . J Mol Biol 1973; 74:403-6. [PMID: 4571235 DOI: 10.1016/0022-2836(73)90380-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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1093
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Chang S, Young RS. The organic analysis and carbon chemistry of lunar samples: their significance for exobiology. SPACE LIFE SCIENCES 1972; 3:315-9. [PMID: 4405502 DOI: 10.1007/bf00926760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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1094
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McDonald IG, Feigenbaum H, Chang S. Analysis of left ventricular wall motion by reflected ultrasound. Application to assessment of myocardial function. Circulation 1972; 46:14-25. [PMID: 5039817 DOI: 10.1161/01.cir.46.1.14] [Citation(s) in RCA: 183] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Ultrasound echocardiograms from the septal and posterior left ventricular walls were displayed with a simultaneously recorded electrocardiogram, phonocardiogram, and indirect carotid pulse. These echoes differed in both amplitude and waveform. The contour of the posterior wall echo resembled an inverted ventricular volume curve, while the septal echo was of smaller amplitude and had a characteristic notched appearance. Most of the movement of the left ventricular walls relative to the ultrasound transducer was attributable to systolic contraction and diastolic expansion of the cavity. However, superimposed on this motion due to change in cavity size was movement of the left ventricle as a whole, first anteriorly toward the ultrasound transducer during late systole then posteriorly away from it at the beginning of left ventricular relaxation. These movements added to the amplitude of posterior wall motion but subtracted from the motion of the septum and were responsible for the notch in the waveform of this echo. Attachment superiorly to the aortic root might also have limited septal motion which was less near the base than nearer the apex of the left ventricle.
The internal left ventricular dimension measured by ultrasound was standardized by using the mitral valve as a landmark and by recording the motion of the left side of the interventricular septum and endocardial surface of the posterior left ventricular wall simultaneously. This measurement was reproducible. In normal subjects, the ultrasonic dimension measured 4.40 ± 0.28 cm at the beginning of systole and shortened by 35.5 ± 3.9% at a rate of 1.22 ± 0.31 lengths/sec. By contrast, the average figures for six patients with primary myocardial disease were 6.96 ± 0.43 cm, 14.9 ± 4.2%, and 0.64 ± 0.11 lengths/sec. Calculation of such indices of left ventricular size and of rate and extent of myocardial shortening should be useful in the detection of impaired myocardial function and in following its progress.
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1095
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Duchak JM, Chang S, Feigenbaum H. The posterior mitral valve echo and the echocardiographic diagnosis of mitral stenosis. Am J Cardiol 1972; 29:628-32. [PMID: 5021492 DOI: 10.1016/0002-9149(72)90163-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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1096
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Loew GH, Chadha MS, Chang S. A molecular orbital and chemical study of aminoacetonitrile: a possible prebiotic peptide precursor. J Theor Biol 1972; 35:359-73. [PMID: 5039299 DOI: 10.1016/0022-5193(72)90044-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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1097
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Chang S, Nowinski RC, Nishioka K, Irie RF. Immunological studies on mouse mammary tumors. VI. Further characterization of a mammary tumor antigen and its distribution in lymphatic cells of allogeneic mice. Int J Cancer 1972; 9:409-16. [PMID: 5041612 DOI: 10.1002/ijc.2910090220] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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1098
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Tamura N, Shimada A, Chang S. Further evidence for immune cytolysis by antibody and the first eight components of complement in the absence of C9. Immunol Suppl 1972; 22:131-40. [PMID: 5013908 PMCID: PMC1408206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The reported observations on the slow, low-grade lysis of EAC1-8 were re-examined by using antisera to guinea-pig C9 as a specific inhibitor against C9 to eliminate the possibility that C8 preparations might contain C9 which lyses EAC1-8. Pretreatment of C8 preparation with IgG fraction of the anti-C9 did not result in reduction of the degree of lysis of EAC1-7 by C8. The dose response curve in titration of C8 with EAC1-7 in the absence of C9 was sigmoidal and completely different from that in the presence of excess C9, suggesting that the cell membrane damage caused by C8 might not be the same as that by C9. Sensitized nucleated cells were shown to be lysed similarly by the first eight components of complement, namely C1 to C8.
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1099
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Chang S, Stockert E, Boyse EA, Hämmerling U, Old LJ. Spontaneous release of cytotoxic alloantibody from viable cells sensitized in excess antibody. Immunology 1971; 21:829-38. [PMID: 4940171 PMCID: PMC1408175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
When viable cells sensitized in excess cytotoxic alloantibody are washed and resuspended in antibody-free medium, they spontaneously release appreciable quantities of antibody. The amount released is directly proportional to the concentration of alloantibody during sensitization. Spontaneous release was observed from all cell types tested (thymocytes, lymphocytes, leukaemia cells and ascites sarcoma cells) and with all alloantibodies tested (H-2, θ and Ly-B). In preliminary tests with radio-labelled H-2 antibody, the quantity of antibody released in a period of 2½ hours was 29 per cent of the antibody originally absorbed. Dissociation at 37° was greater (or more rapid) than at 1°. When washed sensitized cells were suspended in antibody directed to an antigen closely adjacent on the cell surface to the site of attachment of the first antibody, release of the first antibody was impeded.
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1100
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Abstract
The echocardiographic findings are described for five patients who had the prolapsed mitral valve syndrome, proven by cardiac catheterization and angiocardiography. In all five patients, the echocardiograms demonstrated posterior displacement of the posterior mitral leaflet during systole. In four of the patients there was also posterior displacement of the anterior leaflet. Four of the five patients had mitral insufficiency, demonstrated by cineangiography. These four patients demonstrated echocardiographic separation of the anterior and posterior leaflets of the mitral valve in late systole. The fifth patient did not show this separation, and she had no mitral insufficiency by selective cineangiography. Two patients were given amyl nitrite during the echocardiographic examination, and the echogram showed earlier separation of the anterior and posterior leaflets as well as lengthening of the murmur. Echocardiography should be a very useful noninvasive, yet direct, method for diagnosing, studying, and following patients with prolapse of the mitral valve.
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