10701
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Zhang Y, Ihlen H, Nitter-Hauge S. Estimation of the peak-to-peak pressure gradient in aortic stenosis by Doppler echocardiography. Int J Cardiol 1986; 10:192-212. [PMID: 3957467 DOI: 10.1016/0167-5273(86)90002-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The present study was designed to develop a new Doppler method to estimate noninvasively the peak-to-peak pressure gradient in patients with aortic stenosis. It was carried out in two steps. In the first study, left heart catheterization data were analysed in 58 patients with aortic stenosis. The peak pressure gradient correlated highly with (r = 0.98) but overestimated significantly the peak-to-peak pressure gradient. The averaged pressure gradient (average of the peak gradient and the gradient at the peak aortic pressure) was found to approximate closely the peak-to-peak pressure gradient (r = 0.99) with a good separation between significant and insignificant aortic stenosis. The ratio of the left ventricular ejection time over the aortic pressure descending time was studied and the beginning of the late one-third systole was chosen as the point for determining the late systolic gradient by the Doppler technique. In the second study, Doppler echocardiography and cardiac catheterization were performed in 35 patients with aortic stenosis. The Doppler-determined peak pressure gradient correlated highly with catheterization-measured peak pressure gradient (r = 0.95) but overestimated significantly the peak-to-peak pressure gradient. The Doppler-determined averaged pressure gradient (average of the peak and the late systolic gradients) estimated accurately the peak-to-peak gradient (r = 0.97) with a good separation between significant and insignificant aortic stenosis. These results demonstrate the limitations of the peak pressure gradient measurement and the reliability of the Doppler-determined averaged pressure gradient for estimation of the peak-to-peak pressure gradient.
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10702
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Zhang Y. [Carriers of epidemic hemorrhagic fever virus in rodents and mites in EHF endemic area]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 1986; 7:26-8. [PMID: 3087624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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10703
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Zhang Y, Nitter-Hauge S, Ihlen H, Rootwelt K, Myhre E. Measurement of aortic regurgitation by Doppler echocardiography. Heart 1986; 55:32-8. [PMID: 3947478 PMCID: PMC1232065 DOI: 10.1136/hrt.55.1.32] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
In an attempt to develop a new approach to the non-invasive measurement of aortic regurgitation, transmitral volumetric flow (MF) and left ventricular total stroke volume (SV) were measured by Doppler and cross sectional echocardiography in 23 patients without aortic valve disease (group A) and in 26 patients with aortic regurgitation (group B). The transmitral volumetric flow was obtained by multiplying the corrected mitral orifice area by the diastolic velocity integral, and the left ventricular total stroke volume was derived by subtracting the left ventricular end systolic volume from the end diastolic volume. The aortic regurgitant fraction (RF) was calculated as: RF = 1 - MF/SV. In group A there was a close agreement between the transmitral volumetric flow and the left ventricular total stroke volume, and the difference between the two measurements did not differ significantly from zero. In group B the left ventricular total stroke volume was significantly larger than the transmitral volumetric flow, and there was good agreement between the regurgitant fractions determined by Doppler echocardiography and radionuclide ventriculography. Discrepancies between the two techniques were found in patients with combined aortic and mitral regurgitation or a low angiographic left ventricular ejection fraction (less than 35%). The effective cardiac output measured by Doppler echocardiography accorded well with that measured by the Fick method. Doppler echocardiography provides a new and promising approach to the non-invasive measurement of aortic regurgitation.
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10704
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Wang NQ, Yu G, Liang YY, Ye AL, Zhang Y, Yuan QZ. [A comparative study on the photodynamic effect, photosensitive side action and toxicity of several China-made photosensitizers]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1986; 21:7-11. [PMID: 2425553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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10705
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10706
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Abstract
Measurement of the mean pressure gradient across the stenotic aortic valve provides important information about the severity of aortic stenosis. However, determination of the mean pressure gradient by Doppler echocardiography has been difficult due to the squared relation between instantaneous velocities pressure gradients. In this study, the velocity curves in aortic stenosis were analysed mathematically to develop a new and simple method for calculating the mean pressure gradient (delta Pm) from Doppler velocity tracings. The new formula is: delta Pm = 8 V2m[Vp/(Vp + Vm)] where Vp is the peak systolic velocity and Vm the mean systolic velocity. Doppler echocardiography and cardiac catheterisation were performed in 41 patients with aortic stenosis to evaluate the accuracy of this mathematical method. There was a high correlation between the peak pressure gradients determined by Doppler technique using a modified Bernoulli equation and by catheterisation (r = 0.95, SEE = 8.58 mmHg), and the difference between the two measurements was not significant. The comparison between the mean pressure gradients determined by Doppler echocardiography using the new formula and by catheterisation yielded a high correlation (r = 0.95, SEE = 5.60 mmHg), and there was no significant difference between the two means. These results demonstrate the reliability of Doppler echocardiography for determining the mean pressure gradient in aortic stenosis using our mathematical method. Measurement of the mean pressure gradient will further enhance the usefulness of Doppler echocardiography in the non-invasive evaluation of patients with aortic stenosis.
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10707
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Zhang Y, Myhre E, Nitter-Hauge S. Noninvasive quantification of the aortic valve area in aortic stenosis by Doppler echocardiography. Eur Heart J 1985; 6:992-8. [PMID: 3830712 DOI: 10.1093/oxfordjournals.eurheartj.a061820] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
To develop a noninvasive approach to the quantification of the stenotic aortic valve area, Doppler echocardiography and cardiac catheterisation were performed in 24 patients with pure aortic stenosis. The transmitral volumetric flow was measured by Doppler echocardiography and calculated as the product of the corrected mitral orifice area (CMA) and the diastolic velocity integral (DVI). The maximal aortic jet velocities were recorded by Doppler technique and integrated to obtain the systolic velocity integral (SVI). Assuming that the aortic and mitral volumetric flows are equal, the aortic valve area (AVA) was calculated as: AVA = CMA X DVI/SVI. Mean pressure gradient and cardiac output were measured during catheterisation and the aortic valve area was calculated by the Gorlin formula. Comparison between the aortic valve area determined by Doppler technique and catheterisation yielded a close correlation (r = 0.92, P less than 0.001), and there was no significant difference between the two measurements. Good correlations of the instantaneous pressure gradient and the stroke volume were also obtained between the two techniques (r = 0.91 and r = 0.90, respectively, P less than 0.001). These results demonstrate that our Doppler echocardiographic method provides a promising approach to the noninvasive quantification of the aortic valve area in aortic stenosis.
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10708
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Zhang Y, Nitter-Hauge S, Myhre E. Determination of the mean pressure gradient in mitral stenosis by Doppler echocardiography. Eur Heart J 1985; 6:858-64. [PMID: 4076197 DOI: 10.1093/oxfordjournals.eurheartj.a061773] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Measurement of the mean pressure gradient provides an important estimation of the severity of mitral stenosis. However, determination of the mean pressure gradient from Doppler recordings has been unsatisfactory using previously described methods. In this study, a new method calculating the mean pressure gradient, the integral method is described. It was developed from mathematical analysis of Doppler velocity curves. Doppler echocardiography and cardiac catheterisation were performed in 23 patients with mitral stenosis to evaluate the accuracy of three current mathematical methods of determining the mean pressure gradient. The mean pressure gradients calculated by the three methods correlated highly with that measured by catheterisation (r = 0.93). However, the mean pressure gradients calculated by the previously described mean velocity square method and the arithmetical average method underestimated significantly that measured by cardiac catheterisation. In contrast, there was no significant difference between the mean pressure gradients calculated by the integral method and measured by cardiac catheterisation. These results confirm the usefulness of Doppler echocardiography for determining the mean pressure gradient in mitral stenosis and demonstrate that among current methods, the integral method provides the most accurate calculations of the mean pressure gradient.
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10709
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Zhang Y, Ihlen H, Myhre E, Levorstad K, Nitter-Hauge S. Measurement of mitral regurgitation by Doppler echocardiography. BRITISH HEART JOURNAL 1985; 54:384-91. [PMID: 4052279 PMCID: PMC481916 DOI: 10.1136/hrt.54.4.384] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In an attempt to develop a new approach to the non-invasive measurement of mitral regurgitation, Doppler echocardiography and left ventriculography were performed in 20 patients without valvar heart disease (group A) and in 30 patients with pure mitral regurgitation (group B). Volumetric flows through the aortic and the mitral orifices were determined by Doppler echocardiography. Aortic flow (AF) was calculated as the product of the aortic orifice area and the systolic velocity integral. The mitral flow (MF) was calculated as the product of the corrected mitral orifice area and the diastolic velocity integral. The mitral regurgitant fraction (RF) was calculated as RF = 1 - AF/MF. In group A aortic and mitral flow were very similar and the difference between the two did not differ significantly from zero. In group B the mitral flow was significantly larger than the aortic flow. There was a good correlation (r = 0.82) between the regurgitant fraction determined by Doppler echocardiography and the regurgitant grades determined by left ventriculography. The regurgitant fraction increased significantly with each grade of severity. These results show that Doppler echocardiography can be used to give a reliable measure of both aortic and mitral flow. This technique is a new and promising approach to the non-invasive measurement of mitral regurgitation.
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10710
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Li SR, Huang M, Zhang Y, Lu G, Wang Q, Chen LX, Zhou GC. Effect of vagus nerve on the action potential duration of ventricular cell of dog. I. Effect of stimulation of vagus nerve and atropine. ACTA ACADEMIAE MEDICINAE WUHAN = WU-HAN I HSUEH YUAN HSUEH PAO 1985; 5:139-46. [PMID: 2999666 DOI: 10.1007/bf02911170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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10711
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Zhang Y. [Studies of the physical measurements and health status of Down's syndrome patients]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 1985; 19:206-8. [PMID: 2932320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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10712
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Zhang Y, Rushbrook JI, Shafiq SA. Avian adductor profundus muscle: characterization of a pure slow tonic region by histochemical, monoclonal antibody and peptide mapping studies. J Muscle Res Cell Motil 1985; 6:333-45. [PMID: 2933426 DOI: 10.1007/bf00713173] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The fibre type composition of the avian adductor profundus (AP) muscle which is composed of a thick white posterior part (Post. AP) and a thin red anterior part (Ant. AP) was investigated. Using the histochemical ATPase technique, monoclonal antibody analysis of myosin and C-protein isoforms, and electrophoretic and peptide mapping analyses of myosin, we have established that the Post. AP is composed of essentially pure slow tonic fibres similar to those of the anterior latissimus dorsi muscle (ALD). The Ant. AP, on the other hand, is shown to contain a mixture of slow and fast fibres, the latter giving immunocytochemical reactions atypical of the fast fibres. The larger size of the Post. AP in comparison with the ALD muscle should provide significantly more tissue for biochemical studies of tonic fibres than was previously available.
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10713
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Zhang Y. [Parietal cell vagotomy with pyloric dilatation for pyloric obstruction]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 1985; 23:356, 382. [PMID: 4053851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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10714
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Tang ZD, Zhang Y, Wang LT. [Determination of urinary bradykinin in liver cirrhosis]. ZHONGHUA NEI KE ZA ZHI 1985; 24:348-9, 381-2. [PMID: 4017751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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10715
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Zheng G, Guo S, Zhang Y, Wang J. [A preliminary inquiry into the problem of floating population in Shanghai city proper]. REN KOU YAN JIU = RENKOU YANJIU 1985:2-7. [PMID: 12341124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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10716
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Barbier J, Corro G, Zhang Y, Bournville J, Franck J. Coke formation on bimetallic platinum/rhenium and platinum/iridium catalysts. ACTA ACUST UNITED AC 1985. [DOI: 10.1016/s0166-9834(00)84470-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10717
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Zhang Y. [Applying information to improve family planning in Gaoping County]. REN KOU YAN JIU = RENKOU YANJIU 1985:20-1. [PMID: 12341115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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10718
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Zhang Y, Nitter-Hauge S, Ihlen H, Myhre E. Doppler echocardiographic measurement of cardiac output using the mitral orifice method. Heart 1985; 53:130-6. [PMID: 3966956 PMCID: PMC481730 DOI: 10.1136/hrt.53.2.130] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cardiac output was determined in 20 patients with various cardiac conditions by measuring the cross sectional area of the mitral orifice by echocardiography and the transmitral flow by the Doppler technique. Cardiac output was calculated by multiplying the corrected mitral orifice area by the maximum diastolic velocity integral recorded by the pulsed mode. The results were compared with that obtained by the Fick method. The correlation for cardiac output by the two techniques was high in the whole group, particularly in patients without mitral regurgitation. There was also a good correlation for stroke volume determined by the two methods. Cardiac output was significantly overestimated by the continuous mode and in patients with mitral regurgitation. These results show that the mitral orifice method provides a new and reliable approach to the non-invasive measurement of cardiac output.
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10719
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Shen GL, Zhang Y, Yu RQ. [Studies on PVC membrane anisodamine selective electrodes]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1985; 20:151-4. [PMID: 4036622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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10720
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Zhang Y, Shafiq SA. A freeze-fracture study of postembryonic differentiation of latissimus dorsi muscles of the chicken. J Morphol 1985; 183:145-53. [PMID: 3973926 DOI: 10.1002/jmor.1051830203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The differentiation of fiber type characteristics in the anterior (ALD) and posterior (PLD) latissimus dorsi muscles is examined by the freeze-fracture technique in 1-, 7- and 30-day-old chicks. Several characteristics of plasma membrane (caveolae, rectilinear arrays, intramembranous particles) and sarcoplasmic reticulum which show fiber type differences in the adult ALD and PLD muscles are compared in the developmental stages. The caveolar density in the ALD fibers is about 20/microns2 at 1 day increasing to about 37/microns2 at 30 days, whereas in the PLD fibers it remains at about 20/microns2 during this period. The distribution of the caveolae in the two muscles is different from the beginning; in the ALD fibers the caveolae are distributed throughout the plasma membrane and in PLD fibers they are patterned into clusters overlying the I band regions. The density of intramembranous particles of 1-day ALD and PLD plasma membranes appears similar, but by 7 days the particle counts in the sarcolemma of the ALD muscle are about twice as numerous as those in the PLD muscle. The rectilinear arrays are virtually absent in the ALD muscle, whereas in the PLD muscle their density is about 10/microns2 at 1 day and about 20/microns2 at 7 days. Already at 1 day posthatching the SR in ALD and PLD fibers has the adult configuration, i.e., an open irregular network in ALD fibers and periodically arranged tubules with triadic expansions in the PLD fibers.(ABSTRACT TRUNCATED AT 250 WORDS)
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10721
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Tewarson RP, Stephenson JL, Garcia M, Zhang Y. On the solution of equations for renal counterflow models. Comput Biol Med 1985; 15:287-95. [PMID: 4042634 DOI: 10.1016/0010-4825(85)90012-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The results of a comparative study of three discretization techniques and the solution of the resulting algebraic equations by three methods is given. For this study, a four-tube central core model with diffusion in the core was selected and equations were derived for a coherent and efficient implementation. The results of this study show that sparse matrix techniques that take the physiological connectivity of the kidney lead to significant savings in computer storage, running time and overall cost.
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10722
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Zhang Y, Matijević E. Stability of monodispersed hematite sols in the presence of citric acid. Colloid Polym Sci 1984. [DOI: 10.1007/bf01451544] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10723
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Liang J, Zhang Y. The studies on the phase transition of LiIO 3. Acta Crystallogr A 1984. [DOI: 10.1107/s0108767384096045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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10724
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Li SR, Zeng JT, Ding BC, Gu RM, Huang M, Zhang Y, Zhang Y. Simultaneous recording of ECG and transmembrane action potentials of ventricular cells of anesthetized rabbit under natural breathing. ACTA ACADEMIAE MEDICINAE WUHAN = WU-HAN I HSUEH YUAN HSUEH PAO 1984; 4:21-2. [PMID: 6700923 DOI: 10.1007/bf02856944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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10725
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Reynolds JD, Golden WL, Zhang Y, Hiles DA. Ocular abnormalities in terminal deletion of the long arm of chromosome seven. J Pediatr Ophthalmol Strabismus 1984; 21:28-32. [PMID: 6423801 DOI: 10.3928/0191-3913-19840101-08] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Patients with distal deletions of the long arm of chromosome 7q have been reported with a variety of non-specific findings. Ocular findings have been limited to hypertelorism, palpebral fissure abnormalities, strabismus and speckled irides and no intraocular pathology with the exception of one case with unilateral optic nerve coloboma. We report a patient with terminal deletion of the long arm of chromosome 7 with marked ocular abnormalities including severe microphthalmus and large retinal colobomas.
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