301
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Abstract
High-resolution Fourier transform spectra of LiH and LiD were recorded in the far-infrared region, 100-360 cm-1, and the mid-infrared regions, 800-1200 cm-1 and 2000-3000 cm-1. A total of 261 pure rotational lines and 678 rovibrational lines were measured for the isotopomers 6LiH(D) and 7LiH(D). Molecular constants for the X1Sigma+ ground state in the form of mass-dependent Dunham Yij's and mass-independent Dunham Uij's were determined from a data set of 1476 lines, consisting of our measured line positions and previously reported microwave, millimeter-wave, and infrared lines. An effective internuclear potential for the ground electronic state where the Born-Oppenheimer part is modeled as a parameterized modified-Morse function was also determined from a fit of the data. Copyright 1998 Academic Press.
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Affiliation(s)
- M Dulick
- National Solar Observatory, National Optical Astronomy Observatories, Tucson, Arizona, 85726
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302
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Abstract
The main problem encountered in the MALDI-TOF analysis of polydisperse polymers is mass discrimination against high-mass oligomers. This work investigated some of the causes of this problem by using PMMAs as the polymer analytes. It was found that both instrumental and matrix factors could lead to this problem. Among the instrumental factors, detector saturation resulting from strong signals of matrix-related and low-mass oligomer ions can be a potential major cause of this problem. Since most of the ion detectors do not have an adequate dynamic range to avoid saturation, detection saturation could be a fundamental limitation, especially when the molar ratio of high- to low-mass oligomers is small. A quantitative analysis was also performed to examine the matrix effect. IAA and HABA were selected for this study. It was found that mass discrimination occurred in both cases, but the use of HABA led to more profound mass discrimination. This shows that the use of improper matrixes could be another source causing mass discrimination. Hence, unless new approaches are developed, one must be cautious in using MALDI-TOF for directly measuring MWDs of polydisperse polymers, especially those highly polydisperse polymers.
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Affiliation(s)
- H Rashidzadeh
- Department of Chemistry, Cleveland State University, Ohio 44115, USA
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303
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Jin J, Guo B, Kong X. [Multilocular cyst of kidney]. Zhonghua Wai Ke Za Zhi 1998; 36:57-8. [PMID: 11715545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
OBJECTIVE Multilocular cyst of kidney is a rare, unique and characteristic renal lesion with benign biologic behavior. We report a case of the disease. METHODS It was confirmed by operation and pathology. RESULTS It is difficult to distinguish radiologically multilocular cyst of kidney from cystic renal carcinoma and wilms tumor. CONCLUSION Surgical intervention is the only effective treatment and method to differentiate multilocular cyst of kidney from a malignant lesion of the kidney.
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Affiliation(s)
- J Jin
- Institute of Urology, Beijing Medical University, Beijing 100034
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304
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Guo B, Stein JL, van Wijnen AJ, Stein GS. ATF1 and CREB trans-activate a cell cycle regulated histone H4 gene at a distal nuclear matrix associated promoter element. Biochemistry 1997; 36:14447-55. [PMID: 9398163 DOI: 10.1021/bi971781s] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Proteins of the ATF/CREB class of transcription factors stimulate gene expression of several cell growth-related genes through protein kinase A-related cAMP response elements. The promoter activity of cell cycle regulated histone H4 genes is regulated by at least four principal cis-acting elements which mediate G1/S phase control and/or enhancement of transcription during the cell cycle. Using protein-DNA interaction assays we show that the H4 promoter contains two ATF/CREB recognition motifs which interact with CREB, ATF1, and ATF2 but not with ATF4/CREB2. One ATF/CRE motif is located in the distal promoter at the nuclear matrix-associated Site IV, and the second motif is present in the proximal promoter at Site I. Both ATF/CRE motifs overlap binding sequences for the multifunctional YY1 transcription factor, which has previously been shown to be nuclear matrix associated. Subnuclear fractionation reveals that there are two ATF1 isoforms which appear to differ with respect to DNA binding activity and partition selectively between nuclear matrix and nonmatrix compartments, consistent with the role of the nuclear matrix in regulating gene expression. Site-directed mutational studies demonstrate that Site I and Site IV together support ATF1- and CREB-induced trans-activation of the H4 promoter. Thus, our data establish that ATF/CREB factors functionally modulate histone H4 gene transcription at distal and proximal promoter elements.
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Affiliation(s)
- B Guo
- Department of Cell Biology, University of Massachusetts Medical Center, Worcester 01655, USA
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305
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Guo LF, Ma JH, Guo B. [Monitoring of FiO2 mask under nebulized oxygen therapy for post-heart surgery patients]. Zhonghua Hu Li Za Zhi 1997; 32:625-626. [PMID: 9496008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Using Oxygen-Meter measure FiO2 directly inside the patient's mask in different oxygen flow. The purpose was to realize the actual FiO2 that patient inspirated. So oxygen therapy can be carried on correctly and scientifically and provide basis for respiratory monitoring and management post heart surgery. When patient breathe in oxygen in mask nebulize way, a porbe of oxygen meter was put in through a side hole 10 minutes later, the result was recorded. It demonstrated that when oxygen flow was 5L/min FiO2 inside mask was 56% approximately 58%. That means it's not correct to determine FiO2 according to the oxygen flow meter. The oxygen-meter should be used to monitor in order to avoid complications caused by incorrect adjustment and ensure the post heart surgery patient to recovery quickly.
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Affiliation(s)
- L F Guo
- Military Bethune International Peace Hospital, Shijiazhuang
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306
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Abstract
Two of the main problems associated with matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) analysis of polymers are mass discrimination and poor reproducibility. This paper shows that the use of binary solvent systems is one of the causes of these problems. It was observed that the presence of a second solvent such as water in the PMMA solution could cause significant mass discrimination and varying polymer distributions, which can be varied by over 50% when PMMA 4K was used as the polymer sample. In general, a small amount of a second solvent tends to result in less severe mass discrimination but varying distributions, while large amounts of a second solvent are more likely to cause more systematic and severe mass discrimination. Except for a few cases, mass discrimination was observed to be against larger oligomers. Moreover, it was observed that this effect varies with the matrix, main solvent, and sample preparation used. The importance of this work is that it provides guidance for one to develop a better sample preparation protocol to minimize the mass discrimination and poor reproducibility problems. Several potential sources leading to water contamination were identified. Finally, a simple method to verify if amounts of a second solvent are sufficiently high to cause mass discrimination is also discussed.
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Affiliation(s)
- H Chen
- Department of Chemistry, Cleveland State University, Ohio 44115, USA
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307
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Zhang Y, Geng J, Guo B. [The development of a multifunctional irrigator of cardioplegia fluid]. Zhongguo Yi Liao Qi Xie Za Zhi 1997; 21:281-282. [PMID: 11189278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
For a better myocardium protection, we invented an irrigator. It can be used in any kinds of CPB machines, It can perfusate both crystal fluid and blood at the same time or separately. It can monitor the perfussion temperature and pressure And it can adjust the composition of perfussion fluid at will.
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Affiliation(s)
- Y Zhang
- Bethune International Peace Hospital
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308
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Guo B, Jaovisidha S, Sartoris DJ, Ryu KN, Berthiaume MJ, Clopton P, Brossman J, Resnick D. Correlation between ossification of the stylohyoid ligament and osteophytes of the cervical spine. J Rheumatol Suppl 1997; 24:1575-81. [PMID: 9263154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To investigate the correlation between ligamentous ossification or osteophytes of the cervical spine and ossification of the styloid process and stylohyoid ligament, and to determine any relation between diffuse idiopathic skeletal hyperostosis (DISH) of the thoracic spine and ossification of the styloid process and stylohyoid ligament. METHODS Four patients having cervical spine DISH, an elongated styloid process and/or variable patterns of stylohyoid ligament ossification, and clinical findings compatible with Eagle's syndrome are described. Cervical computed tomography scans of 100 patients who also had lateral radiographs of the thoracic spine were reviewed. Point biserial and Spearman rank correlation analysis, McNemar test, chi-squared test, and Fisher's exact test were used to determine correlation between elongation of the styloid process and/or ossification of the stylohyoid ligament and (1) ligamentous ossification or osteophytes of the cervical spine (the characteristic spinal manifestation of DISH), and/or (2) DISH of the thoracic spine. RESULTS (1) Elongation of the styloid process and variable patterns of ossification of the proximal, middle, and distal parts of the stylohyoid ligament, and (2) enlargement of this ligament were significantly correlated with transverse and anteroposterior dimensions of ligamentous ossification or osteophytes of the cervical spine at various levels. The prevalence of such abnormalities of this process and ligament was not significantly different between the patients with and without thoracic spine DISH. CONCLUSION Variable types of styloid process-stylohyoid ligament complex abnormalities have significant correlation with ligamentous ossification and osteophytes of the cervical spine.
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Affiliation(s)
- B Guo
- Department of Radiology, Veterans Affairs Medical Center, San Diego, CA 92161, USA
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309
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Anderson DJ, Guo B, Xu Y, Ng LM, Kricka LJ, Skogerboe KJ, Hage DS, Schoeff L, Wang J, Sokoll LJ, Chan DW, Ward KM, Davis KA. Clinical chemistry. Anal Chem 1997; 69:165R-229R. [PMID: 9195857 DOI: 10.1021/a1970008p] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- D J Anderson
- Department of Chemistry, Cleveland State University, Ohio 44115, USA
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310
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Abstract
The infrared emission spectra of NaCl and KCl have been recorded at high resolution with a Fourier transform spectrometer. A total of 929 lines belonging to 8 vibrational bands, 1-0 to 8-7, for Na35 Cl, 252 lines of 1-0, 2-1, and 3-2 bands of Na37 Cl, and 355 lines of 1-0, 2-1, 3-2, and 4-3 bands of K35 Cl have been measured and combined with the existing microwave and millimeter-wave data to obtain a set of refined molecular constants. The data for Na35 Cl and Na37 Cl have also been fitted to determine the Dunham Yij constants and mass-reduced Dunham constants Uij . In one fit all Uij 's were treated as adjustable parameters while in a second fit only Ui 0 's and Ui 1 's were allowed to vary freely with the remaining Uij constants determined by the constraints imposed by the Dunham model. In addition, the internuclear potential energy parameters were determined by fitting the entire NaCl data set to the eigenvalues of the Schrodinger equation containing a parameterized potential energy function.
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Affiliation(s)
- RS Ram
- Department of Chemistry, University of Arizona, Tucson, Arizona, 85721
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311
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He S, Guo B. [Observation of pollen morphology of medicinal Epimedium plants in Guizhou province by SEM]. Zhongguo Zhong Yao Za Zhi 1997; 22:268-70, 318. [PMID: 11038955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The pollens of 11 species and one variety of Epimedium grown in Guizhou Province have been observed by SEM. The morphological characters (especially ektexine sculpture) of the pollens are described and the correlation among pollen morphology plant forms and chemical constituents is discussd.
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Affiliation(s)
- S He
- Guizhou Institute of Chinese Materia Medica, Guiyang
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312
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Ma JH, Guo B, Guo LF. [Nursing in arterial duct ligation under thoracoscopy]. Zhonghua Hu Li Za Zhi 1997; 32:209-10. [PMID: 9325740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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313
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Guo B, Aslam F, van Wijnen AJ, Roberts SG, Frenkel B, Green MR, DeLuca H, Lian JB, Stein GS, Stein JL. YY1 regulates vitamin D receptor/retinoid X receptor mediated transactivation of the vitamin D responsive osteocalcin gene. Proc Natl Acad Sci U S A 1997; 94:121-6. [PMID: 8990171 PMCID: PMC19252 DOI: 10.1073/pnas.94.1.121] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The responsiveness of genes to steroid hormones is principally mediated by functional interactions between DNA-bound hormone receptors and components of the transcriptional initiation machinery, including TATA-binding protein, TFIIB, or other RNA polymerase II associated factors. This interaction can be physiologically modulated by promoter context-specific transcription factors to facilitate optimal responsiveness of gene expression to hormone stimulation. One postulated regulatory mechanism involves the functional antagonism between hormone receptors and nonreceptor transcription factors interacting at the same hormone response element. Here we demonstrate that the multifunctional regulator YY1 represses 1,25-dihydroxyvitamin D3 (vitamin D)-induced transactivation of the bone tissue-specific osteocalcin gene. We identify YY1 recognition sequences within the vitamin D response element (VDRE) of the osteocalcin gene that are critical for YY1-dependent repression of vitamin D-enhanced promoter activity. We show that YY1 and vitamin D receptor (VDR)/retinoid X receptor heterodimers compete for binding at the osteocalcin VDRE. In addition, we find that YY1 interacts directly with TFIIB, and that one of the two tandemly repeated polypeptide regions of TFIIB spanning the basic domain is responsible for this interaction. TFIIB and VDR can also interact directly, and these factors synergize to mediate transactivation. Our results suggest that YY1 regulates vitamin D enhancement of osteocalcin gene transcription in vivo by interfering with the interactions of the VDR with both the VDRE and TFIIB.
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Affiliation(s)
- B Guo
- Department of Cell Biology, University of Massachusetts Medical Center, Worcester 01655, USA
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314
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Bostick DT, Arnold WD, Guo B, Burgess MW. The Evaluation of Sodium-Modified Chabazite Zeolite and Resorcinol-Formaldehyde Resin for the Treatment of Contaminated Process Wastewater. SEP SCI TECHNOL 1997. [DOI: 10.1080/01496399708003230] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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315
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George A, Chiang Y, Guo B, Arabshahi A, Cai Z, Wilson W. [6] Second virial coefficient as predictor in protein crystal growth. Methods Enzymol 1997; 276:100-110. [DOI: 10.1016/s0076-6879(97)76052-x] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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316
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Phillips JD, Guo B, Yu Y, Brown FM, Leibold EA. Expression and biochemical characterization of iron regulatory proteins 1 and 2 in Saccharomyces cerevisiae. Biochemistry 1996; 35:15704-14. [PMID: 8961933 DOI: 10.1021/bi960653l] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Iron-regulatory proteins (IRPs) 1 and 2 are cytosolic RNA-binding proteins that bind to specific stem-loop structures, termed iron-responsive elements (IREs) that are located in the untranslated regions of specific mRNAs encoding proteins involved in iron metabolism. The binding of IRPs to IREs regulates either translation or stabilization of mRNA. Although IRP1 and IRP2 are similar proteins in that they are ubiquitously expressed and are negatively regulated by iron, they are regulated by iron by different mechanisms. IRP1, the well-characterized IRP in cells, is a dual-function protein exhibiting either aconitase activity when cellular iron is abundant or RNA-binding activity when cellular iron is scarce. In contrast, IRP2 lacks detectable aconitase activity and functions exclusively as an RNA-binding protein. To study and compare the biochemical characteristics of IRP1 and IRP2, we expressed wild-type and mutant rat IRP1 and IRP2 in the yeast Saccharomyces cerevisiae. IRP1 and IRP2 expressed in yeast bind the IRE RNA with high affinity, resulting in the inhibition of translation of an IRE-reporter mRNA. Mutant IRP2s lacking a 73 amino acid domain unique to IRP2 and a mutant IRP1 containing an insertion of this domain bound RNA, but lacked detectable aconitase activity, suggesting that the presence of this domain prevents aconitase activity. Like IRP1, the RNA-binding activity of IRP2 was sensitive to inactivation by N-ethylmaleimide (NEM) or 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), indicating IRP2 contains a cysteine(s) that is (are) necessary for RNA binding. However, unlike IRP1, where reconstitution of the 4Fe-4S cluster resulted in a loss in RNA-binding activity, the RNA-binding activity of IRP2 was unaffected using the same iron treatment. These data suggested that IRP2 does not contain a 4Fe-4S cluster similar to the cluster in IRP1, indicating that they sense iron by different mechanisms.
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Affiliation(s)
- J D Phillips
- Department of Medicine, University of Utah, Salt Lake City 84112, USA
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317
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Abstract
The emission spectra of the gaseous polycyclic aromatic hydrocarbons (PAHs) naphthalene, chrysene, and pyrene were recorded in the far-infrared (far-IR) region. The vibrational bands that lie in the far IR are unique for each PAH molecule and allow discrimination among the three PAH molecules. The far-IR PAH spectra, therefore, may prove useful in the assignment of unidentified spectral features from astronomical objects.
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Affiliation(s)
- K Zhang
- Centre for Molecular Beams and Laser Chemistry, Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
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318
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Li W, Guo B, Xiao P, Pan J, Lu M, Zhang R. [Chemical constituents of Epimedium wanshanense S. Z. He et Guo]. Zhongguo Zhong Yao Za Zhi 1996; 21:614-6, 640. [PMID: 9772630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Five flavonoids were isolated from Epimedium wanshanense and identified as sagittatoside B, anhydroicaritin-3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-rhamnopyranoside, sagittatoside A, ikarisoside B and desmethylanhydroicaritin-3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L- rhamnopyranoside by means of IR, UV, 1HNMR, 13CNMR, MS and chemical evidence. They were obtained from this plant for the first time.
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Affiliation(s)
- W Li
- Institute of Medicinal Plant, Chinese Academy of Medical Sciences, Beijing
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319
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Sanderson NM, Guo B, Jacob AE, Handley PS, Cunniffe JG, Jones MN. The interaction of cationic liposomes with the skin-associated bacterium Staphylococcus epidermidis: effects of ionic strength and temperature. Biochim Biophys Acta 1996; 1283:207-14. [PMID: 8809101 DOI: 10.1016/0005-2736(96)00099-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cationic liposomes have been prepared from dipalmitoylphosphatidylcholine (DPPC), cholesterol (Chol) and stearylamine (SA). These phospholipid vesicles were exposed to adsorbed biofilms of the skin-associated bacteria Staphylococcus epidermidis, to which they showed a strong affinity. The interaction (as assessed by the apparent monolayer coverage of the biofilms by liposomes) was described in terms of a Langmuir adsorption isotherm which enabled determination of the maximum theoretical coverage of the bacterial surface and association/dissociation constants. The interaction was shown to be dependent on the ionic strength of the surrounding medium; on increasing the ionic strength the biofilm-vesicle dissociation constant decreased. This suggested that the adsorption was mediated by electrostatic effects. The adsorption of the vesicles was examined at various temperatures, enabling determination of thermodynamic parameters for the interaction. The adsorbed state of the liposomes was energetically favoured and the interaction was enthalpy driven. The Gibbs energies of adsorption were in a range from -15 to -19 kJ mol-1 and the enthalpies of adsorption from -26 to -22 kJ mol-1. Studies using cell populations of different hydrophobicity showed that the hydrophobic character of the bacterial cells also had an effect on the adsorption of the vesicles to the biofilm.
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Affiliation(s)
- N M Sanderson
- School of Biological Sciences, University of Manchester, UK
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320
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Guo B, Xiao P. [Determination of flavonoids in different parts of five epimedium plants]. Zhongguo Zhong Yao Za Zhi 1996; 21:523-5, 574. [PMID: 9772637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
By means of RP-HPLC, nine major flavonoids in different parts of five Epimedium plants incorporated in the Chinese Pharmacopoeia (1990 edn.) were analyzed. The result shows that the total contents of nine flavonoids in four species were rhizome and roots > leaves > stems. Nevertheless, in terms of composition of the main constituents and relative contents of the five species, the leaves are similar to the stems but different from the rhizome and roots. The difference may be reflected in their pharmaceutical effects and thus deserves attention.
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Affiliation(s)
- B Guo
- Institute of Medicinal Plant, Chinese Academy of Medical Sciences, Peking Union Medical College
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321
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Guo B, Yu J, Xiao P. [Chemical constituents from the whole plant of Epimedium fargesii Franch]. Zhongguo Zhong Yao Za Zhi 1996; 21:353-5, 383. [PMID: 9388923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Six chemical constituents were isolated from the whole plant of Epimedium fargesii and identified as epimedoside A, ikarisosids C, epimedin B, epimedin C, icariin and hyperin by means of UV, IR, 1H-NMR, 13C-NMR and MS spectral analysis. They were isolated from this plant for the first time.
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Affiliation(s)
- B Guo
- Institute of Medicinal Plant, Chinese Academy of Medical Sciences, Beijing
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322
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Guo B, Anzai J, Osa T. Modification of a glassy carbon electrode with diols for the suppression of electrode fouling in biological fluids. Chem Pharm Bull (Tokyo) 1996; 44:860-2. [PMID: 8681418 DOI: 10.1248/cpb.44.860] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The surface of a glassy carbon (GC) electrode was modified covalently with ethyleneglycol, diethyleneglycol, 1,2-propanediol, and 1,3-propanediol by electrochemical oxidation in order to suppress the electrode fouling originating from non-specific adsorption of serum proteins. Human serum albumin (HSA) was adsorbed significantly on the surface of a bare GC electrode, which was monitored by cyclic voltammetry in the presence of Fe(CN)6(4)-/Fe(CN)6(3)-ions. In contrast, the diol-modified GC electrodes were scarcely fouled in HSA solution and even in human serum. The results were explained reasonably based on the hydrophilic nature of the diol-modified GC surface.
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Affiliation(s)
- B Guo
- Pharmaceutical Institute, Tohoku University, Sendai, Japan
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323
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Phillips JD, Kinikini DV, Yu Y, Guo B, Leibold EA. Differential regulation of IRP1 and IRP2 by nitric oxide in rat hepatoma cells. Blood 1996; 87:2983-92. [PMID: 8639920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Iron-regulatory proteins (IRP1 and IRP2) are RNA-binding proteins that bind to stem-loop structures known as iron-responsive elements (IREs). IREs are located in the 5'- or 3'-untranslated regions (UTRs) of specific mRNAs that encode proteins involved in iron homeostasis. The binding of IRPs to 5' IREs represses translation of the mRNA, whereas the binding of IRPs to 3' IREs stabilizes the mRNA. IRP1 and IRP2 binding activities are regulated by intracellular iron levels. In addition, nitric oxide (NO.) increases the affinity of IRP1 for IREs. The role of NO. in the regulation of IRP1 and IRP2 in rat hepatoma cells was investigated by using the NO.-generating compound S-nitroso-N-acetylpenicillamine (SNAP), or by stimulating cells with multiple cytokines and lipopolysaccharide (LPS) to induce NO. production. Mitochondrial and IRP1 aconitase activities were decreased in cells producing NO(.). NO. increased IRE binding activity of IRP1, but had no effect on IRE binding activity of IRP2. The increase in IRE binding activity of IRP1 was coincident with the translational repression of ferritin synthesis. Transferrin receptor (TfR) mRNA levels were increased in cells treated with NO.-generating compounds, but not in cytokine- and LPS-treated cells. Our data indicate that IRP1 and IRP2 are differentially regulated by NO. in rat hepatoma cells, suggesting a role for IRP1 in the regulation of iron homeostasis in vivo during hepatic inflammation.
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Affiliation(s)
- J D Phillips
- Eccles Program in Human Molecular Biology and Genetics, University of Utah, Salt Lake City, USA
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324
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Abstract
The adsorption behavior of serum albumin onto the surface of platinum, gold, and glassy carbon electrodes was studied in relation to the electrode potential, by using cyclic voltammetry and a quartz-crystal microbalance. The kinetics of adsorption was significantly dependent on the electrode potential. The adsorption was highly accelerated by the application of positive potential to the electrode, suggesting an electrostatic interaction between the negatively charged albumin molecules and the positively polarized electrode as the origin of the accelerated adsorption. The adsorption of albumin on the electrodes was irreversible with respect to dilution of the albumin solution, while the quartz-crystal microbalance data showed that albumin forms a monomolecular layer on the electrode surface. Protein adsorption on electrode surface in serum was also examined.
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Affiliation(s)
- B Guo
- Pharmaceutical Institute, Tohoku University, Sendai, Japan
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325
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Huang Z, Guo B, Liang K. [Effects of Radix angelicae sinensis on systemic and portal hemodynamics in cirrhotics with portal hypertension]. Zhonghua Nei Ke Za Zhi 1996; 35:15-8. [PMID: 9275639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The present study investigated effects of Radix angelicae sinensis (RAS) on systemic and portal hemodynamics in cirrhotic patients with portal hypertension. The results demonstrated that, after intravenous injection of the agent (20 mg.kg-1.min-1), systemic hemodynamics (heart rate, mean arterial pressure, inferior vena cava pressure, systemic vascular resistance, cardiac output, cardiac index) remained unchanged, but portal hemodynamics signicantly improved, wedged hepatic venous pressure (WHVP) (3.79 +/- 0.76 kPa vs 2.72 +/- 0.89 kPa, P < 0.01) and hepatic venous pressure gradient (HVPG) (2.88 +/- 0.73 kPa vs 1.78 +/- 0.68 kPa, P < 0.01) reduced by 29.40 and 35.78 percent respectively. However, anti-portal hypertensive effect of RAS was inverse proportion to the basical level of WHVP or HVPG in the cirrhotics. We conclude that RAS can effectively decrease portal pressure and yet gives no influence on systemic hemodynamics in the cirrhotic patients with portal hypertension.
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Affiliation(s)
- Z Huang
- Department of Hepatogastroenterology, Shanghai First People's Hospital
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326
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Guo B, Odgren PR, van Wijnen AJ, Last TJ, Nickerson J, Penman S, Lian JB, Stein JL, Stein GS. The nuclear matrix protein NMP-1 is the transcription factor YY1. Proc Natl Acad Sci U S A 1995; 92:10526-30. [PMID: 7479833 PMCID: PMC40644 DOI: 10.1073/pnas.92.23.10526] [Citation(s) in RCA: 138] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
NMP-1 was initially identified as a nuclear matrix-associated DNA-binding factor that exhibits sequence-specific recognition for the site IV regulatory element of a histone H4 gene. This distal promoter domain is a nuclear matrix interaction site. In the present study, we show that NMP-1 is the multifunctional transcription factor YY1. Gel-shift and Western blot analyses demonstrate that NMP-1 is immunoreactive with YY1 antibody. Furthermore, purified YY1 protein specifically recognizes site IV and reconstitutes the NMP-1 complex. Western blot and gel-shift analyses indicate that YY1 is present within the nuclear matrix. In situ immunofluorescence studies show that a significant fraction of YY1 is localized in the nuclear matrix, principally but not exclusively associated with residual nucleoli. Our results confirm that NMP-1/YY1 is a ubiquitous protein that is present in both human cells and in rat osteosarcoma ROS 17/2.8 cells. The finding that NMP-1 is identical to YY1 suggests that this transcriptional regulator may mediate gene-matrix interactions. Our results are consistent with the concept that the nuclear matrix may functionally compartmentalize the eukaryotic nucleus to support regulation of gene expression.
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Affiliation(s)
- B Guo
- Department of Cell Biology, University of Masachusetts Medical Center, Worcester 01655, USA
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327
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Abstract
Iron regulatory proteins (IRP1 and IRP2) are RNA-binding proteins that bind to specific structures, termed iron-responsive elements (IREs), that are located in the 5'- or 3'-untranslated regions of mRNAs that encode proteins involved in iron homeostasis. IRP1 and IRP2 RNA binding activities are regulated by iron; IRP1 and IRP2 bind IREs with high affinity in iron-depleted cells and with low affinity in iron-repleted cells. The decrease in IRP1 RNA binding activity occurs by a switch between apoprotein and 4Fe-4S forms, without changes in IRP1 levels, whereas the decrease in IRP2 RNA binding activity reflects a reduction in IRP2 levels. To determine the mechanism by which iron decreases IRP2 levels, we studied IRP2 regulation by iron in rat hepatoma and human HeLa cells. The iron-dependent decrease in IRP2 levels was not due to a decrease in the amount of IRP2 mRNA or to a decrease in the rate of IRP2 synthesis. Pulse-chase experiments demonstrated that iron resulted in a 3-fold increase in the degradation rate of IRP2. IRP2 degradation depends on protein synthesis, but not transcription, suggesting a requirement for a labile protein. IRP2 degradation is not prevented by lysosomal inhibitors or calpain II inhibitors, but is prevented by inhibitors that block proteasome function. These data suggest the involvement of the proteasome in iron-mediated IRP2 proteolysis.
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Affiliation(s)
- B Guo
- Eccles Program in Human Molecular Biology and Genetics, University of Utah, Salt Lake City 84112, USA
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328
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Guo B, Brown FM, Phillips JD, Yu Y, Leibold EA. Characterization and expression of iron regulatory protein 2 (IRP2). Presence of multiple IRP2 transcripts regulated by intracellular iron levels. J Biol Chem 1995; 270:16529-35. [PMID: 7622457 DOI: 10.1074/jbc.270.28.16529] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Iron regulatory proteins (IRP1 and IRP2) are RNA-binding proteins that bind to stem-loop structures, termed iron-responsive elements (IREs), present in either the 5'- or 3'-untranslated regions of specific mRNAs. The binding of IRPs to 5'-IREs inhibits translation of mRNA, whereas the binding of IRPs to 3'-IREs stabilizes mRNA. To study the structure and regulation of IRP2, we isolated cDNAs for rat and human IRP2. The derived amino acid sequence of rat IPR2 is 93% identical with that of human IRP2 and is present in lower eukaryotes, indicating that IRP2 is highly conserved. IRP1 and IRP2 share 61% overall amino acid identity. IRP2 is ubiquitously expressed in rat tissues, the highest amounts present in skeletal muscle and heart. IRP2 is encoded by multiple mRNAs of 6.4, 4.0, and 3.7 kilobases. The 3'-untranslated region of rat IRP2 contains multiple polyadenylation signals, two of which could account for the 4.0-kb and 3.7-kb mRNAs. The 3.7-kb mRNA is increased in iron-depleted cells and occurs with a reciprocal decrease in the 6.4-kb transcript. These data suggest that the 3.7-kb mRNA is produced by alternative poly(A) site utilization in iron-depleted cells.
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Affiliation(s)
- B Guo
- Department of Medicine, University of Utah, Salt Lake City 84112, USA
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329
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Abstract
High-resolution infrared spectra of sunspot umbrae have been recorded with the 1-meter Fourier transform spectrometer on Kitt Peak. The spectra contain a very large number of water absorption features originating on the sun. These lines have been assigned to the pure rotation and the vibration-rotation transitions of hot water by comparison with high-temperature laboratory emission spectra.
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Affiliation(s)
- L Wallace
- Kitt Peak National Observatory, National Optical Astronomy Observatories, Tucson, AZ 85726, USA
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330
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Zhang YM, Guo B, Li FY. [Monitoring and care of postoperative patients suffering from ventricular septal rupture with pulmonary hypertension]. Zhonghua Hu Li Za Zhi 1995; 30:13-5. [PMID: 7664356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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331
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Abstract
Adsorption of serum albumin on the surface of platinum and gold electrodes was highly accelerated by the application of a constant potential to the electrodes. The accelerated adsorption was significant at the electrode potential of 0.5-1.0 V vs. Ag/AgCl, even in the diluted solution of albumin (0.01%).
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Affiliation(s)
- J Anzai
- Pharmaceutical Institute, Tohoku University, Sendai, Japan
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332
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Braun V, Guo B, Zhang KQ, Dulick M, Bernath P, McRae G. Infrared emission spectroscopy at 100 μm. Vibration—rotation spectrum of CsI. Chem Phys Lett 1994. [DOI: 10.1016/0009-2614(94)00998-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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333
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Guo B, Yu Y, Leibold EA. Iron regulates cytoplasmic levels of a novel iron-responsive element-binding protein without aconitase activity. J Biol Chem 1994; 269:24252-60. [PMID: 7523370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Iron-responsive element-binding proteins (IRE-BPs) are cytosolic proteins that bind to a conserved RNA stem-loop, termed the iron-responsive element (IRE), that is located in the 5'- or 3'-untranslated regions of mRNAs involved in iron metabolism. Binding of the IRE-BP to 5'-IREs represses translation, whereas binding to 3'-IREs stabilizes the mRNA. The previously identified IRE-BP (BP1) contains a 4Fe-4S cluster and has sequence homology to mitochondrial aconitase. The 4Fe-4S cluster is important for iron-dependent regulation: BP1 containing iron has low affinity for the IRE and contains aconitase activity, whereas BP1 lacking iron has high affinity for the IRE, but lacks aconitase activity. A second IRE-BP (BP2) has been identified in rat tissues and cells and exhibits many of the hallmarks of an IRE-BP, including binding to the IRE and functioning as a translational repressor of IRE-containing RNAs. BP1 and BP2 RNA binding activities are decreased in extracts from cells treated with iron, indicating that BP1 and BP2 are negatively regulated by iron. Although BP1 and BP2 share similar characteristics, they differ in two significant ways. Unlike BP1 levels, which do not change when RNA binding activity decreases in response to iron, BP2 decreases to undetectable levels in extracts from cells treated with iron; and unlike BP1, BP2 does not have aconitase activity. These data indicate that BP1 and BP2 are distinct proteins that have similar specificity for IRE binding and that function similarly in translation, but are regulated by iron via different mechanisms.
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Affiliation(s)
- B Guo
- Department of Medicine, University of Utah, Salt Lake City 84112
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334
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Guo B, Yu Y, Leibold E. Iron regulates cytoplasmic levels of a novel iron-responsive element-binding protein without aconitase activity. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)51075-4] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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335
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Sun X, Ji X, Zheng Y, Guo B. Primary chronic angle-closure glaucoma in Chinese--a clinical exploration of its pathogenesis and natural course. Yan Ke Xue Bao 1994; 10:176-85. [PMID: 7744211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Forty-three cases (86 eyes) of primary chronic angle-closure glaucoma were randomly selected. An additional 44 cases (77 eyes) of primary acute angle-closure glaucoma and 30 normal subjects (34 eyes) were also randomly enrolled as control groups for comparison in the clinical study. Ultrasonic biometric measurements of the anterior chamber depth, lens thickness and axial length of the eyeball were performed. Using an potic microgauge attached to the slit-lamp, the entrance of anterior chamber angle was also calculated. The clinical manifestations and the natural course, including the characteristic appearance of anterior chamber angle, the form of peripheral anterior synechia as well as the facility of outflow, were carefully investigated. There were significant differences in the biometric parameters of the anterior segment of eye among above three groups. The facts reveal that the anatomic features of eyeball, especially in the anterior segment differentiate from those of primary acute angle-closure glaucoma. Follow-up study for the early stage cases showed that topical administration of miotics and/or peripheral iridectomy can effectively prevent iris from forming peripheral anterior synechia and thus halt its development. The criteria of diagnosis and the principles of prevention and treatment at the early stage cases were presented. The pathogenesis was discussed. We emphasized that the progressive stage after intermittent attacks of primary acute angle-closure glaucoma should not be confused with primary chronic angle-closure glaucoma.
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Affiliation(s)
- X Sun
- Department of Ophthalmology, Eye & ENT Hospital, Shanghai Medical University, China
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336
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Guo B, Ansbacher W, Pinnington EH, Ji Q, Berends RW. Beam-laser lifetime measurements for low-lying quartet states in Fe II. Phys Rev A 1992; 46:641-644. [PMID: 9907903 DOI: 10.1103/physreva.46.641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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337
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Affiliation(s)
- E A Leibold
- Human Molecular Biology and Genetics Program, University of Utah, Salt Lake City 84112
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338
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Feng Z, Qiao W, Guo B, Zu A, Zhao J. [Immunological identification of tiger-bone]. Zhongguo Zhong Yao Za Zhi 1992; 17:196-8, 254. [PMID: 1418546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Anti-tiger sera were prepared by using tiger serum proteins to immunize the rabbits. Tiger-bone can be identified by the specific serological reaction between the anti-tiger sera and the tiger-bone proteins.
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Affiliation(s)
- Z Feng
- Harbin Municipal Institute for Drug Control
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339
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Guo B, Tian DA, Liang KH, Li SB, Guo JY. [Effect of pituitrin or phentolamine alone or in combination on WHVP and systemic hemodynamics in patients with liver cirrhosis]. J Tongji Med Univ 1990; 10:207-12. [PMID: 1711584 DOI: 10.1007/bf02887932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We observed the effect of pituitrin and phentolamine alone or in combination on wedged hepatic venous pressure (WHVP) and systemic hemodynamics in 28 patients with cirrhosis. The results showed that either of these drugs used separately could lead to reduction in WHVP, each of them could also cause by-effects on systemic hemodynamics. When pituitrin in combination with phentolamine was administered, no change could be found in inferior vena cava pressure, mean arterial pressure, pulse rate and cardiac index. This suggested that pituitrin in combination with phentolamine could not only efficaciously decrease WHVP, but also counteract side effects on systemic hemodynamics of each other and improve hepatic microcirculation. Our study provided evidence for the usefulness of the combination of the two drugs in controlling bleeding from esophagus varices.
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Affiliation(s)
- B Guo
- Institut für Hepatologie, Tongji Klinik, Tongji Medizinische Universität, Wuhan
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