3701
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Chen Z, Lin CD. Classification of Coulombic three-body systems in hyperspherical coordinates. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1990; 42:18-31. [PMID: 9903771 DOI: 10.1103/physreva.42.18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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3702
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Tsang MB, Kim YD, Carlin N, Chen Z, Gelbke CK, Gong WG, Lynch WG, Murakami T, Nayak T, Ronningen RM, Xu HM, Zhu F, Sobotka LG, Stracener DW, Sarantites DG, Majka Z, Abenante V. Azimuthal distributions of fission fragments and alpha particles emitted in the reactions 36Ar+238U at E/A=20 and 35 MeV and 14N+238U at E/A=50 MeV. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1990; 42:15-19. [PMID: 9966686 DOI: 10.1103/physrevc.42.r15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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3703
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Chen Z, Spruch L. Lower bounds on the ground-state energy and necessary conditions for the existence of bound states: The few-body problem. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1990; 42:133-138. [PMID: 9903785 DOI: 10.1103/physreva.42.133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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3704
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Emanuel PD, Peiper SC, Chen Z, Sheng DC, Zuckerman KS. Specific inhibition of interleukin 3 bioactivity by a monoclonal antibody reactive with hematopoietic progenitor cells. Proc Natl Acad Sci U S A 1990; 87:4449-52. [PMID: 2352928 PMCID: PMC54132 DOI: 10.1073/pnas.87.12.4449] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
HIM1, originally designated HI98, a murine monoclonal IgM antibody raised against human mononuclear cells, has been reported at the Fourth International Leukocyte Typing Workshop (called antibody M0141) to be the only one of 157 antibodies tested that inhibited binding of interleukin 3 (IL-3) to KG-1 human acute myelogenous leukemia cells and normal human monocytes. We have carried out detailed studies of the selective effect of HIM1 on IL-3-mediated stimulation of hematopoietic progenitors. Preincubation of normal human bone marrow mononuclear cells, depleted of adherent cells and T cells, with HIM1 antibody resulted in a dose-dependent inhibition of IL-3-mediated stimulation of both erythroid burst-forming units (maximum inhibition 55%) and granulocyte/macrophage colony-forming units (maximum inhibition 49%). HIM1 antibody had no effect on growth of erythroid colony-forming units in culture. In addition, preincubation of the cells with HIM1 antibody had no deleterious effect on granulocyte/macrophage colony-stimulating factor-induced growth of either erythroid bursts or granulocyte/macrophage colonies. To be certain that the HIM1 antibody did not react directly with IL-3 itself, we attempted to use immunodepletion to remove IL-3 that had been added to our culture medium. Although we were able to remove IL-3 bioactivity by immunodepletion with anti-IL-3 antibody bound to Sepharose beads, beads with attached HIM1 did not remove IL-3 activity from the medium. Polymorphonuclear neutrophils bind high levels of HIM1, although they have very few or no detectable IL-3 receptors. Therefore, this antibody appears to recognize a cell surface antigen that is critical for optimal IL-3 binding and bioactivity but is not the actual IL-3 receptor.
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3705
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Chen Z, Hedner J, Hedner T. Substance P in the ventrolateral medulla oblongata regulates ventilatory responses. J Appl Physiol (1985) 1990; 68:2631-9. [PMID: 1696574 DOI: 10.1152/jappl.1990.68.6.2631] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Local injection of substance P (SP) into the ventral portion of the nucleus gigantocellularis, nucleus reticularis lateralis, and nucleus retrofacialis of the ventrolateral medulla oblongata (VLM) or direct application on the ventral surface of the medulla oblongata caused marked stimulation of tidal volume (VT) and/or minute ventilation (VE). The ventilatory response to hypoxia was significantly blunted after SP in the VLM but not in the dorsal medulla oblongata (DM) (nucleus tractus solitarius). The SP antagonist [D-Pro2,D-Trp7,9]SP almost completely inhibited this response when applied locally to a wide area of the superficial layer of the VLM but not of the DM. Unilateral or bilateral application of 0.3-1.5 nmol of the SP antagonist in the VLM (corpus trapezoideum and the caudal region extending from the rootlets of the nucleus hypoglossus to the first cervical segment) markedly attenuated the response to a 5% CO2 inhalation. The inhibition of the CO2 response was seen after [D-Pro2,D-Trp7,9]SP in the rostral areas of the medulla oblongata corresponding to the corpus trapezoideum and the caudal region extending from the rootlets of the nucleus hypoglossus to the first cervical segment of the cervical cord. Electric somatosensory-induced ventilatory stimulation could be depressed by approximately 70% by [D-Pro2,D-Trp7,9]SP locally applied on the surface of the VLM. We conclude that SP is involved in the hypoxic, hypercapnic, and somatosensory ventilatory responses in the rat. However, these respiratory reflexes are mediated via different neuronal pools in the medulla oblongata, mainly the VLM.
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3706
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Qian X, Chen Z. [Pathologic morphology of the indented tongue]. ZHONG XI YI JIE HE ZA ZHI = CHINESE JOURNAL OF MODERN DEVELOPMENTS IN TRADITIONAL MEDICINE 1990; 10:337-9, 324. [PMID: 2397551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This paper use the methods of light microscope, electronmicroscope to observe the appearance of pathology and morphology of the convex and concave parts of the indented tongue edge, and examine the histology of normal tongue edge as a contrast. The authors consider that the main pathological changes of the indented tongue are: Thinning of the epithelial layer; change of rough endoplastic retica; reducing in tonofilaments; edema of cells and tissues, and decreasing in elastic fibers and collagenic fibers, etc.
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3707
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Freedhoff H, Chen Z. Resonance fluorescence of a two-level atom in a strong bichromatic field. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1990; 41:6013-6022. [PMID: 9903004 DOI: 10.1103/physreva.41.6013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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3708
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Kong H, Morgan RD, Chen Z. Identification of a new type II restriction endonuclease, BsaAI. Nucleic Acids Res 1990; 18:2832. [PMID: 2339077 PMCID: PMC330790 DOI: 10.1093/nar/18.9.2832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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3709
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Grausz D, Lanotte M, Valensi F, Hillion J, Chen SJ, Chen Z, Morinet F, Berger R. A new Ph1+, bcr cell line derived from a patient with ALL-L1 gained autonomy in culture concomitant to CD23 expression. Leukemia 1990; 4:359-64. [PMID: 2143794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A permanent cell line, LEF1, has been established from the cells of an adult suffering from a Philadelphia positive acute lymphoblastic leukemia. The LEF1 cell line was obtained by maintaining peripheral blood cells from the patient in culture on a fibroblast feeder; subsequently, an autonomously growing cell population, independent of that feeder layer, developed. The karyotype of the cell line, 46, t(9;22)(q34;q11), was different from the karyotype at diagnosis which had 53 chromosomes and two Philadelphia chromosomes. Furthermore, compared with the initial leukemic blasts, the immortalized cell had three differences in surface phenotype (CD23+, CD11b-, CD10-). However, molecular studies indicated that the breakpoint in the 3' part of the first intron of the BCR gene was unchanged, confirming the leukemic origin of LEF1. The cell line was shown to be Epstein-Barr virus negative.
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3710
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Chen Z, Duan X. [Mechanism of the antiasthmatic effect of total coumarins in the fruit of Cnidium monnieri (L.)Cuss]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1990; 15:304-5, 320. [PMID: 2275785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Total coumarins in the fruit of Cnidium monnieri show a marked protective effect against bronchial asthma induced by inhalation of histamine in conscious guinea pig. In vitro these total coumarins can relax the contraction of the isolated trachea in guinea pigs induced by histamine as well as increase the perfusion rate of isolated lung preparation of guinea pig. These actions, however, may be blocked by propranolol. Besides, these coumarins cannot increase the heart rate and arterial blood pressure in anesthetized rats. All this shows that the antiasthmatic effect of total coumarins in the fruit of Cnidium monnieri is mediated by beta 2-receptor.
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3711
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Chen Z, Yang AD, Fei HA, Gong WL. Cytogenetic study on acute lymphoblastic leukemia. JOURNAL OF TONGJI MEDICAL UNIVERSITY = TONG JI YI KE DA XUE XUE BAO 1990; 10:31-6. [PMID: 2348486 DOI: 10.1007/bf02909119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
During 1987-1988 cytogenetic studies were performed in 30 patients with acute lymphoblastic leukemia (ALL). Of the 30 patients 15 (10 children and 5 adults) were found to have abnormal karyotypes including 8 cases (27%) of pseudodiploidy, 2 cases (7%) of hypodiploidy, one case (3%) of low-hyperdiploidy (modal number 47-50), and 4 cases (13%) of high-hyperdiploidy (modal number greater than 50). Immunological classification was performed by using monoclonal antibodies in 26 patients, and the most common immunophenotype was C-ALL. The patients with abnormal karyotypes were more likely to be NuLL-ALL (6 in 14) as compared with patients with normal karyotype (1 in 12). In our series, there was no significant difference between the patients with and without cytogenetic changes in regard of clinical findings such as FAB classification, the rate of complete remission, percentage of lymphoblasts in bone marrow cells and blood picture.
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3712
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Chen Z, Lu L, Shirley M, Lee WR, Chang SH. Site-directed mutagenesis of glycine-14 and two "critical" cysteinyl residues in Drosophila alcohol dehydrogenase. Biochemistry 1990; 29:1112-8. [PMID: 2108721 DOI: 10.1021/bi00457a003] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Three amino acid residues (glycine-14, cysteine-135, and cysteine-218) previously speculated to be important for the structure and function of Drosophila melanogaster alcohol dehydrogenase have been investigated by using site-directed mutagenesis followed by kinetic analysis and chemical modification. Mutating glycine-14 to valine (G14V) virtually inactivates Drosophila ADH, and substitution of alanine at this position (G14A) causes a 31% decrease in activity. Thermal denaturation and kinetic and inhibition studies further demonstrate that replacing glycine-14 with either alanine or valine leads to structural changes in the NAD binding domain. These results provide direct evidence for the role played by glycine-14 in maintaining the correct conformation in the NAD binding domain. On the other hand, changing of cysteine-135, -218, or both to alanine (C135A, C218A, and C135A/C218A) causes no decrease in the catalytic activity of the enzyme, indicating that neither of the cysteinyl residues is essential for catalysis. C135A and wild-type enzyme are both inactivated by DTNB. In contrast, C218A and C135A/C218A are unaffected by DTNB treatment. DTNB modification of cysteine-218 can be prevented by the substrates NAD and 2-propanol, suggesting that cysteine-218 may be in the vicinity of the active site. Cysteine-135 which is normally insensitive to DTNB becomes accessible in the presence of 2-propanol and/or NAD, suggesting a conformational change induced by binding of these substrates.
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3713
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Berger R, Chen SJ, Chen Z. Philadelphia-positive acute leukemia. Cytogenetic and molecular aspects. CANCER GENETICS AND CYTOGENETICS 1990; 44:143-52. [PMID: 2404570 DOI: 10.1016/0165-4608(90)90041-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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3714
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Ma X, Lu R, Song J, Chen Z. [Effects of concentration and ratio of N, P and K on seedlings of Panax quinquefolium L]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1990; 15:78-81, 125. [PMID: 2390175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Results of the orthogonal experiment of N, P and K are as follows: (1) The highest growth rate occurs in treatment 4 (N100ppm, P25ppm, K250ppm) and other features are also good. So this treatment can be used in hydroponics of seedling of P. quinquefolium. (2) The influences of N, P and K concentration on the contents of ginsenosides in different parts of seedling are different. The content of ginsenosides in aerial part is 14.72-16.72%, higher than 3.24-4.00% in root.
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3715
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Chen Z. [The status of negative charge of the RBC and glomeruli and its relation to proteinuria in adriamycin nephrosis in rats]. ZHONGHUA YI XUE ZA ZHI 1990; 70:91-3, 8. [PMID: 2161275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The status of negative charge on RBC and glomeruli and its relation to proteinuria of adriamycin nephrosis in rats were studied by electron computerized picture analysis. The results showed that the negative charge (NC) on glomeruli decreased significantly at 48 hrs and 14 days after ADR injection although there was no proteinuria simultaneously. There was a positive relation between the changes of NC on glomeruli and those on RBC (r = 0.77, p less than 0.01), and there was negative relation between either of them and proteinuria respectively (r = -0.5140, p less than 0.05; r = -0.5231, p less than 0.01). The focal fusions of foot processes occurred prior to the onset of proteinuria.
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3716
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Kimmelstiel C, Goldberg R, Decker R, Chen Z, Osganian V, Drady P, Gore J, Alpert J. Impact of female gender on incidence and prognosis of infarction-associated heart failure: The worcester heart attack trial. J Am Coll Cardiol 1990. [DOI: 10.1016/0735-1097(90)92387-h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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3717
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Tao R, Chen Z, Sheng P. First-principles Fourier approach for the calculation of the effective dielectric constant of periodic composites. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 41:2417-2420. [PMID: 9993979 DOI: 10.1103/physrevb.41.2417] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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3718
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Chen Z, Lin CD. Systematics of autoionization widths of doubly excited states of atoms. PHYSICAL REVIEW. A, GENERAL PHYSICS 1989; 40:6712-6715. [PMID: 9902069 DOI: 10.1103/physreva.40.6712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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3719
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Macintyre E, d'Auriol L, Amesland F, Loiseau P, Chen Z, Boumsell L, Galibert F, Sigaux F. Analysis of junctional diversity in the preferential V delta 1-J delta 1 rearrangement of fresh T-acute lymphoblastic leukemia cells by in vitro gene amplification and direct sequencing. Blood 1989; 74:2053-61. [PMID: 2529925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
To define the junctional diversity of T-cell antigen receptor delta gene rearrangements in fresh T-acute lymphoblastic cells and to correlate cell phenotype with the coding potential of rearrangements, we determined the junctional nucleotide sequences of 13 T-cell antigen receptor delta gene rearrangements involving the preferentially rearranged V (V delta 1) and J (J delta 1) segments using in vitro gene amplification and direct sequencing. We showed that, as in gamma delta+ cell lines, extensive junctional diversity exists in these clones and that this diversity is due both to random nucleotide deletions/additions and to the use of at least two D delta segments. We also showed that a high percentage of these rearrangements are potentially translatable (7:13) and that such functional rearrangements occur in both surface CD3+ and CD3- cells. Comparison of alpha beta versus gamma delta surface expression demonstrates that all CD3+ T acute lymphoblastic leukemias with a functional V delta 1-J delta 1 rearrangement express a surface gamma delta receptor and are recognized by the anti-delta monoclonal antibody delta TCS1, whereas a control CD3+ gamma delta+ leukemic case that had not undergone V delta 1 rearrangement was delta TCS1-. In addition, expression of this monoclonal antibody is not restricted by V gamma or C gamma usage or by the covalent or noncovalent link between gamma and delta chains.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Blotting, Southern
- Gene Amplification
- Gene Rearrangement, T-Lymphocyte
- Genes
- Humans
- Leukemia-Lymphoma, Adult T-Cell/genetics
- Molecular Sequence Data
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell, gamma-delta
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3720
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Chen SJ, Chen Z, Font MP, d'Auriol L, Larsen CJ, Berger R. Structural alterations of the BCR and ABL genes in Ph1 positive acute leukemias with rearrangements in the BCR gene first intron: further evidence implicating Alu sequences in the chromosome translocation. Nucleic Acids Res 1989; 17:7631-42. [PMID: 2678002 PMCID: PMC334872 DOI: 10.1093/nar/17.19.7631] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In the Philadelphia positive bcr negative acute leukemias (Ph1+bcr- AL), the chromosomal breakpoints on chromosome 22 have been shown clustered within 10.8kb (bcr2) and 5kb (bcr3) fragments of the first intron of the BCR gene. We previously reported that the breakpoints were localized in Alu repeats on chromosomes 9 and 22 in a Ph1+bcr- acute lymphoblastic leukemia with a rearrangement involving bcr2. Molecular data of two other Ph1 translocations, one a Ph1+bcr- acute myeloblastic leukemia in the bcr2 region, and the other an acute lymphoblastic leukemia in the bcr3 region are presented. In the former, the breakpoints on chromosomes 9 and 22 are localized in Alu repeats, in regions with two inverted Alu sequences, as in our previously reported case. In the second leukemia, the breakpoints are not located in Alu sequences, but such repeats are found in their vicinity. The implications of these findings are discussed.
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3721
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Chen Z, Johnson WR, Spruch L. Atomic screening effects on electron-neutrino angular correlation and beta -decay asymmetry in allowed transitions. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1989; 40:1376-1383. [PMID: 9966111 DOI: 10.1103/physrevc.40.1376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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3722
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Wang ZG, Zhu Y, Wang SH, Pu LP, Du YH, Zhang H, Yuan C, Chen Z, Wei ML, Pu LQ. Recognition and management of Budd-Chiari syndrome: report of one hundred cases. J Vasc Surg 1989; 10:149-56. [PMID: 2760994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Budd-Chiari syndrome is an unusual form of portal hypertension caused by occlusion of the hepatic venous outflow, and it is often confused with portal hypertension caused by liver cirrhosis. Its prognosis is poor, and optimal therapy remains to be established. This is a report of 100 confirmed cases of this syndrome treated from December 1982 to March 1988 at two vascular centers in China. Sixty-two male and 38 female patients, 15 to 62 years of age (mean age, 32.6 years) were treated. Seventy-six patients had intractable ascites, 56 had esophageal varices, and 22 had upper gastrointestinal bleeding. There were 37 cases of membranous obstruction, 57 cases of occlusion of the inferior vena cava above the confluence of the hepatic veins, and 6 cases of occlusion of the hepatic veins. Eighty-one patients were operated on. Operative mortality rate was 8.6% (7/81). Follow-up from 2 to 66 months revealed that 58 of the patients operated on (72%) had good results, whereas 11 of 19 (58%) patients treated nonoperatively died within 2 months after admission. On the basis of these data we conclude that the operative procedure must be tailored to the cause and underlying pathologic characteristics. Mesoatrial shunting is the operation of choice for patients with occlusion of the retrohepatic inferior vena cava and hepatic veins, and inferior vena cava--atrial shunting is the operation of choice for patients with occlusion of the inferior vena cava and patency of the hepatic veins. Membranotomy is used for patients with inferior vena cava webbing, and mesocaval shunting is used for patients with intrahepatic venous occlusion only.(ABSTRACT TRUNCATED AT 250 WORDS)
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3723
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Eberhard WL, Chen Z. Lidar discrimination of multiple fluorescent tracers of atmospheric motions. APPLIED OPTICS 1989; 28:2996-3007. [PMID: 20555642 DOI: 10.1364/ao.28.002996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
An analytical study demonstrates the feasibility of simultaneous lidar measurement and discrimination of multiple fluorescent particle tracers of air motions. Equations are presented for evaluating signal-to-noise ratio and interfering signals. Matrix methods can solve for the concentrations of several tracers from simultaneous measurements in at least as many spectral receiver channels, even when fluorescence spectra overlap. Two example systems, one with crosstalk and another without, are evaluated for accuracy in the presence of shot noise and calibration errors. Potential applications include observing the structure of complex flows and measuring the effect of release location on atmospheric transport and dispersion.
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3724
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Kim YD, Tsang MB, Gelbke CK, Lynch WG, Carlin N, Chen Z, Fox R, Gong WG, Murakami T, Nayak TK, Ronningen RM, Xu HM, Zhu F, Bauer W, Sobotka LG, Stracener D, Sarantites DG, Majka Z, Abenante V, Griffin H. Multifragment emission observed for the reaction 36Ar + 238U at E/A=35 MeV. PHYSICAL REVIEW LETTERS 1989; 63:494-497. [PMID: 10041089 DOI: 10.1103/physrevlett.63.494] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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3725
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Linton JP, Yen JY, Selby E, Chen Z, Chinsky JM, Liu K, Kellems RE, Crouse GF. Dual bidirectional promoters at the mouse dhfr locus: cloning and characterization of two mRNA classes of the divergently transcribed Rep-1 gene. Mol Cell Biol 1989; 9:3058-72. [PMID: 2674679 PMCID: PMC362775 DOI: 10.1128/mcb.9.7.3058-3072.1989] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The mouse dihydrofolate reductase gene (dhfr) is a housekeeping gene expressed under the control of a promoter region embedded in a CpG island--a region rich in unmethylated CpG dinucleotides. A divergent transcription unit exists immediately upstream of the dhfr gene which is coamplified with dhfr in some but not all methotrexate-resistant cell lines. We show that the promoter region for this gene pair consists of two bidirectional promoters, a major and minor promoter, which are situated within a 660-base-pair region upstream of the dhfr ATG translation initiation codon. The major promoter controls over 90% of dhfr transcription, while the minor promoter directs the transcription of the remaining dhfr mRNAs. The major promoter functions bidirectionally, transcribing a divergent 4.0-kilobase poly(A) mRNA (class A) in the direction opposite that of dhfr transcription. The predicted protein product of this mRNA is 105 kilodaltons. The minor promoter also functions bidirectionally, directing the transcription of at least two divergent RNAs (class B). These RNAs, present in quantities approximately 1/10 to 1/50 that of the class A mRNAs, are 4.4- and 1.6-kilobase poly(A) mRNAs. cDNAs representing both class A and class B mRNAs have been cloned from a mouse fibroblast cell line which has amplified the dhfr locus (3T3R500). DNA sequence analysis of these cDNAs reveals that the class A and class B mRNAs share, for the most part, the same exons. On the basis of S1 nuclease protection analysis of RNA preparations from several mouse tissues, both dhfr and divergent genes showed similar levels of expression but did show some specificity in start site utilization. Computer homology searches have revealed sequence similarity of the divergent transcripts with bacterial genes involved in DNA mismatch repair, and we therefore have named the divergently transcribed gene Rep-1.
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