551
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Gustavson L, Shi H, Palmer R, Siepman N, Craft J. Drug interaction between clarithromycin and fluconazole in healthy subjects. Clin Pharmacol Ther 1996. [DOI: 10.1038/sj.clpt.1996.241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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552
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Shi H, Xu H, Liang G. [Effects of a platelet-activating factor antagonist ONO-6240 on antigen induced eosinophil infiltration into the airways]. ZHONGHUA NEI KE ZA ZHI 1995; 34:753-6. [PMID: 8731847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
An in vivo mouse model of allergic bronchial asthma was developed to investigate the effects of a platelet activating factor antagonist ONO-6240 on eosinophil (EOS) recruitment into the mouse airway. In the present study, no EOS could be found in bronchoalveolar lavage fluid (BALF) from normal control mice. However, chronic ovalbumin challenge of sensitized mice induced significant bronchoalveolar eosinophilia (9.68 +/- 0.72 x 10(8)/L). In three groups of mice treated intraperitoneally with different doses of ONO-6240 (0.1, 1.0, 10.0 mg/kg), the medication produced 42.1% (5.60 +/- 0.97 x 10(8)/L, P < 0.01), 58.8% (3.99 +/- 0.84 x 10(8)/L, P < 0.01), and 72.6% (2.65 +/- 0.71 x 10(8)/L, P < 0.01) inhibition, respectively, of the antigen-induced influx of EOS into BALF. It was found that the prevention of EOS infiltration into airway with ONO-6240 was accompanied by decrements of both interleukin (IL)-5 and IL-2 levels. These data indicated that ONO-6240 prevented airway eosinophilia by inhibiting production of IL-5 and IL-2. Our results suggested that ONO-6240 may be of value in treating human asthmatic patients.
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553
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Shi F, Shi H, Li Z. [Low dosage of homoharringtonine for prevention of cicatrization after glaucoma filtering surgery]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1995; 31:345-6. [PMID: 8706581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
To prevent the cicatrization of filtering blebs after glaucoma filtering surgery, subconjunctival injections of low dosage homoharringtonine were administered to 22 glaucomatous eyes (20 patients) postoperatively. The percentage of functional filtering blebs was 90.9% and the mean postoperative IOP was 2.04 +/- 0.68 kPa (1 kPa = 7.5 mmHg). In comparison with the control group, the differences were very significant (P < or = 0.01). The results suggest that the toxicity of low dosage of homoharringtonine be very low, it inhibit fibroblast proliferation and play important roles in the formation of the functional filtering blebs and elevation of the success rate of filtration operation.
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554
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Shi H, Cloutier P, Sanche L. Low-energy-electron stimulated desorption of metastable particles from condensed N2 and CO. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:5385-5391. [PMID: 9981729 DOI: 10.1103/physrevb.52.5385] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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555
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Yan H, Shi H. Unmet family planning needs. CHINA POPULATION TODAY 1995; 12:22-3. [PMID: 12290270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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556
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Che P, Xu J, Shi H, Ma Y. Quantitative determination of serum iron in human blood by high-performance capillary electrophoresis. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1995; 669:45-51. [PMID: 7581886 DOI: 10.1016/0378-4347(95)00041-g] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A capillary electrophoretic (HPCE) method that can be used to quantitatively determine trace amounts of iron has been developed and applied to determine the iron level in human serum. After precipitation of serum proteins, Fe(III) in the serum is reduced to Fe(II) with hydroxylamine hydrochloride, and a stable Fe(II)-1,10-phenanthroline complex is formed by adding 1,10-phenanthroline to the supernatant containing 2.5 mM ammonium acetate-acetic acid at pH 5.0. The Fe(II)-1,10-phenanthroline complex, [Fe(C12H8N2)3]2+, has a very strong absorbance at 270 nm (with a molar absorptivity of approximately 9.2.10(4)). By measuring the absorbance of [Fe(C12H8N2)3]2+ at 270 nm, the iron level in human serum can be precisely quantified. The interference from copper, a major interference in serum, can be totally eliminated due to the complete separation of [Fe(C12H8N2)3]2+ and the Cu(II)-1,10-phenanthroline complex. In addition, other problems that usually occurred with conventional spectrophotometric methods, such as co-precipitation and occlusion of iron during sample pretreatment, are significantly minimized due to the ability to wash the precipitate and the higher detection sensitivity. With this method, a single drop (10 microliters) of serum would be sufficient to determine the serum iron concentration. The method is reliable, sensitive, rapid and reproducible. Thus it is highly suitable for use in the clinical laboratory.
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557
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Shi H, Segaloff DL. A role for increased lutropin/choriogonadotropin receptor (LHR) gene transcription in the follitropin-stimulated induction of the LHR in granulosa cells. Mol Endocrinol 1995; 9:734-44. [PMID: 8592519 DOI: 10.1210/mend.9.6.8592519] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Follitropin (FSH) has been shown in previous studies to stimulate the induction of the LH/CG receptor (LHR) and LHR mRNA in the granulosa cells of diethylstilbesterol-primed immature rats. The present studies were undertaken to identify the mechanisms underlying the hormone-dependent induction of the LHR in rat granulosa cells. The effect of FSH on LHR mRNA stability was determined by measuring the decay of LHR mRNA after removal of FSH under conditions where transcription was inhibited. Under these conditions, readdition of FSH had little effect on mRNA stability. However, inhibitors of transcription themselves were found to have a marked effect on stabilizing the LHR mRNA, thus potentially masking an effect of FSH. These results suggest that there is a labile destabilizing factor that constitutively degrades LHR mRNA. At present, it cannot be ascertained whether FSH has any effect on this destabilizing factor. Transcriptional activity of the LHR gene was examined using nuclear run-on assays. It was found that 1) in the absence of FSH, LHR-binding activity and mRNA levels were negligible, but the LHR gene was transcriptionally active in granulosa cells of immature rats; 2) incubations of granulosa cells with FSH or 8-bromo-cAMP significantly increased endogenous LHR gene transcription (approximately 10-fold) under conditions where increases in LHR mRNA were observed; 3) the continuous presence of FSH or 8-bromo-cAMP was required to maintain elevated levels of LHR gene transcription and LHR mRNA; and 4) exogenous estradiol alone had no effect on transcription of the LHR gene although it was able to synergistically enhance FSH-induced LHR expression. These experiments suggest that while the effects of estradiol on LHR induction do not appear to be mediated by an increase in LHR gene transcription, the effects of FSH (or cAMP) on LHR induction are clearly mediated, at least in part, by significant increases in the rate of LHR gene transcription.
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558
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Shi H. A role for increased lutropin/choriogonadotropin receptor (LHR) gene transcription in the follitropin-stimulated induction of the LHR in granulosa cells. Mol Endocrinol 1995. [DOI: 10.1210/me.9.6.734] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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559
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Shi H, Zhao B, Xin W. Scavenging effects of baicalin on free radicals and its protection on erythrocyte membrane from free radical injury. BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 1995; 35:981-994. [PMID: 7549941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Using electron spin resonance (ESR) spin trapping technique, we found that baicalin (B) could scavenge hydroxyl radicals generated from Fenton reaction. It also could scavenge superoxide radicals generated from the reaction system containing xanthine (X) and xanthine oxidase (XO), as was found by using chemiluminescence (CL) method. Kinetic studies on the competition between baicalin and a spin trap 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) in trapping OH showed that baicalin had a kinetic reactive rate constant of the order of 7.7 x 10(11) M-1 s-1 in its reaction with OH, and the studies on the competition between baicalin and ferricytochrome c (f.c.) in trapping O2- gave a kinetic reactive rate constant of 3.2 x 10(6) M-1 s-1 for baicalin in its reaction with O2-. Furthermore, we have investigated the protective effects of baicalin on erythrocyte membranes from hydroxyl free radical injuries. The results showed that baicalin could reduce hydrogen peroxide-induced hemolysis, protect the conformation of sulfhydryl groups (-SH) on membrane proteins and the membrane fluidity of erythrocytes incubated with hydrogen peroxide. The results indicated that baicalin could protect the membranes of erythrocytes from free radical injuries, and it was even more effective than alpha-tocopherol.
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560
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Shi H, Ma Y, Humphrey JH, Craft NE. Determination of vitamin A in dried human blood spots by high-performance capillary electrophoresis with laser-excited fluorescence detection. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1995; 665:89-96. [PMID: 7795805 DOI: 10.1016/0378-4347(94)00520-f] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have developed a high-performance capillary electrophoresis (HPCE) method to analyze the retinol (vitamin A) concentration as retinol-retinol binding protein (holo-RBP) from microvolumes of serum (5-10 microliters) or one to two drops (approximately 20 microliters) of blood collected and air-dried on blood collection filter paper. A 0.64-cm diameter disk was cut from the dried whole blood specimens and the samples were dissolved in a pretreatment buffer and filtered. Filtrate was injected onto the HPCE column for analysis. The separation was carried out in a 60 cm x 50 microns I.D. fused-silica capillary and the running voltage was 20 kV. A He-Cd laser with a wavelength of 325 nm was used for excitation, and the fluorescence of the holo-RBP complex was monitored at 465 nm by a photodiode. A virtual linear relationship was obtained for the retinol concentrations between HPCE and HPLC for 28 serum samples, 19 dried venous blood samples and 9 capillary dried blood spot samples, indicating that valid measures of serum retinol can be obtained from one to two drops of capillary blood collected on filter paper. The absolute detection limit for retinol by HPCE is below 3 micrograms/l. The method is very useful for vitamin A level screening, especially for children and premature new-born babies.
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561
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Ward MM, Hubert HB, Shi H, Bloch DA. Physical disability in older runners: prevalence, risk factors, and progression with age. J Gerontol A Biol Sci Med Sci 1995; 50:M70-7. [PMID: 7874592 DOI: 10.1093/gerona/50a.2.m70] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Concern exists that certain types of exercise, particularly vigorous activity, may increase physical disability among older individuals. We investigated the prevalence of, and risk factors for, physical disability in active older persons (runners), and examined factors influencing the progression of physical disability with age. METHODS Physical disability, measured using the Health Assessment Questionnaire Disability Index, was assessed prospectively in 454 runners, age 50 or greater, over five to seven years by annual mailed questionnaires. Baseline sociodemographic, clinical, and life-style characteristics associated with the presence of any disability over the course of the study were determined and contrasted with those in 292 older non-runners who had been similarly followed. RESULTS Two hundred twenty-two runners (49%) reported some physical disability during the study. The presence of arthritis symptoms at baseline was the most important risk factor for physical disability; older age, greater body mass index, strenuous work-related physical activity, and the use of more medications were also associated with a greater likelihood of physical disability. Among the non-runners, 224 (77%) reported some physical disability, and the presence of arthritis symptoms was also the most important risk factor for physical disability in this group. Age-related changes in physical disability differed between those with and without arthritis symptoms in both the runner and non-runner groups. CONCLUSIONS The presence of arthritis symptoms was an important risk factor for physical disability among both older runners and non-runners, and also identified subgroups of individuals with different progressions of disability with age.
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562
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Jackson DC, Shi H, Singer JH, Hamm PH, Lawler RG. Effects of input pressure on in vitro turtle heart during anoxia and acidosis: a 31P-NMR study. THE AMERICAN JOURNAL OF PHYSIOLOGY 1995; 268:R683-9. [PMID: 7900911 DOI: 10.1152/ajpregu.1995.268.3.r683] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In vitro working hearts of the turtle, Chrysemys picta bellii, paced at 30 beats/min, were studied over a range of input pressures in the following sequence of perfusion conditions: control normoxia, control anoxia, lactacidotic normoxia, and lactacidotic anoxia. Two such series of experiments were performed. In series 1 (n = 12), ventricular pressure (PV) and cardiac output were measured, and power output and dPV/dt were calculated. In series 2 (n = 5), intracellular phosphorus metabolites and intracellular pH (pHi) were also measured using 31P-nuclear magnetic resonance (31P-NMR) spectroscopy. In series 1 all mechanical variables increased with input pressure in generally similar fashion, except during anoxic acidosis, during which mechanical performance was depressed and was increased less or not at all by input pressure. Creatine phosphate (CP) and pHi fell significantly in anoxia and anoxic acidosis, but neither these variables, ATP, CP/ATP, nor, presumably, ADP changed as a function of input pressure with any perfusate despite often large increments in mechanical output. We conclude that anoxia and acidosis act synergistically to depress cardiac function in turtle hearts. Also, the insensitivity of NMR variables to changes in input pressure and cardiodynamics suggests that changes in these variables are unimportant for controlling energy turnover in this preparation.
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563
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Shi H, Rastegar H, Griffin A. Bose-Einstein condensation of a coupled two-component Bose gas. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 51:1075-1080. [PMID: 9962751 DOI: 10.1103/physreve.51.1075] [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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564
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Zhu Y, Cao C, Shi H, Wang Y, Wan X. [Inhibitory effect of anti-motoneuron serum on the neurite outgrowth of spinal cord explants (in vitro) and the cross-reactivity of serum to human and rat motoneurons]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1995; 17:41-5. [PMID: 7781127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The effects of rabbit anti-swine motoneuron serum (RAS), normal rabbit serum (NRS), skeletal muscle extracts (MET, 50 and 100 micrograms/ml) and brain extracts (BET, 50 and 100 micrograms/ml) on neurite outgrowth of neonatal rat spinal cord explants (in vitro) were studied after 5 days of treatment. In comparison with NRS (explants possessing neurite outgrowth accounted for 36.7%, n = 30), the neurite outgrowth of spinal cord explants was significantly accelerated by MET (96.7% of explants had neurite outgrowth), but inhibited by RAS (only 13.3% of the explants had neurite outgrowth). The cross-reactivity of RAS to the spinal motoneuron of swine, humans and rats were also demonstrated by immunocytochemical techniques.
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565
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Lee KW, Shalaby KA, Medhat AM, Shi H, Yang Q, Karim AM, LoVerde PT. Schistosoma mansoni: characterization of the gene encoding Sm23, an integral membrane protein. Exp Parasitol 1995; 80:155-8. [PMID: 7821405 DOI: 10.1006/expr.1995.1018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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566
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Shi H, Jacobi K, Ertl G. Interaction of hydrogen with nitrogen atoms chemisorbed on a Ru(0001) surface. J Chem Phys 1995. [DOI: 10.1063/1.468930] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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567
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Shi H, Ritter GX. A new parallel binary image shrinking algorithm. IEEE TRANSACTIONS ON IMAGE PROCESSING : A PUBLICATION OF THE IEEE SIGNAL PROCESSING SOCIETY 1995; 4:224-226. [PMID: 18289974 DOI: 10.1109/83.342194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A new parallel binary image shrinking algorithm that can be considered as an improvement of Levialdi's (1972) parallel shrinking algorithm and can be used in many image labeling algorithms as a basic operation in order to reduce the storage requirements for local memory and speed up the labeling process is presented. This new parallel shrinking algorithm shrinks an nxn binary image to an image with no black pixels in O(n) parallel steps with a multiplicative constant of 1.5, preserving the 8-connectivity in the shrinking process.
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568
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Cenedella RJ, Shi H. Spatial distribution of 3-hydroxy-3-methylglutaryl coenzyme A reductase messenger RNA in the ocular lens: relationship to cholesterologenesis. J Lipid Res 1994; 35:2232-40. [PMID: 7534808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
This study probes the regulation of cholesterol biosynthesis in the ocular lens by estimating the concentration and distribution of the messenger RNA for the rate-controlling enzyme for sterol synthesis, 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR). Because the lens is dependent on biosynthesis for cholesterol, HMGR activity is crucial for the life-long growth of this organ. Young rat lenses were serially divided into several fractions by dissolution in an SDS-containing buffer and each fraction was equated to a percent of the lens radius based upon its protein content. HMGR enzyme activity and cholesterol synthesis has been shown to disappear from the lens cortex over a narrow arc of radius due to loss of enzyme protein. Using a published competitive reverse transcriptase-polymerase chain reaction method for amplifying HMGR mRNA (Powell, E. E., and P. A. Kroon. 1992. J. Lipid Res. 33: 609-614), an average of about 46,000 copies of this mRNA was estimated per lens at all rat ages examined (5-day-old to adult). However, copies/microgram total RNA decreased with aging. The distribution of HMGR mRNA across 95-60% of the lens radius was essentially uniform at 2000-3000 copies/mm3 tissue. But the very superficial cortex contained 5- to 7-times this concentration and accounted for about 35% of the total copies/lens. We estimated that cells in this region each contained 1 to 2 copies of message, a value similar to the estimated copy number of HMGR message in human lymphocytes (Powell and Kroon, ibid). This suggests that the translational efficiency and stability of lens HMGR mRNA must be very high.(ABSTRACT TRUNCATED AT 250 WORDS)
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569
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Cenedella RJ, Shi H. Spatial distribution of 3-hydroxy-3-methylglutaryl coenzyme A reductase messenger RNA in the ocular lens: relationship to cholesterologenesis. J Lipid Res 1994. [DOI: 10.1016/s0022-2275(20)39929-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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570
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Ma Z, Shi H, Chen B. Isovector meson contribution in the relativistic Hartree-Fock approach for finite nuclei. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1994; 50:3170-3173. [PMID: 9970024 DOI: 10.1103/physrevc.50.3170] [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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571
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Stelzer A, Shi H. Impairment of GABAA receptor function by N-methyl-D-aspartate-mediated calcium influx in isolated CA1 pyramidal cells. Neuroscience 1994; 62:813-28. [PMID: 7870309 DOI: 10.1016/0306-4522(94)90479-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Mechanisms of regulation of GABAA receptor function by intracellular calcium ([Ca2+]i) were examined in cell somata and apical dendrites of pyramidal cells, acutely dissociated from the CA1 hippocampal subfield of adult guinea-pigs. GABAA receptor-mediated currents were measured by whole-cell clamp recordings. N-methyl-D-aspartate receptor-mediated currents were used as conditioning source of calcium influx. Peak amplitudes of somatic GABAA whole-cell currents were reduced to about 15% of control values when net inward charge accumulation by N-methyl-D-aspartate currents reached 1.85 nC. A similar decline of GABAA currents was observed in dendritic recordings. The N-methyl-D-aspartate-mediated reduction of somatic and dendritic GABAA currents was accompanied by a well correlated decrease in peak and chord conductances. Pharmacological blockade of N-methyl-D-aspartate currents by 2-amino-5-phosphonopentanoic acid prevented the N-methyl-D-aspartate-mediated suppression of GABAA responses. The N-methyl-D-aspartate effect was mediated by the calcium component of N-methyl-D-aspartate receptor-mediated currents as demonstrated by a lack of effect in the absence of extracellular calcium and faster N-methyl-D-aspartate-mediated suppression of GABAA responses in lower intracellular 1,2-bis(2-aminophenoxy)ethane-N,N,N',N"-tetra-acetate. N-methyl-D-aspartate-mediated suppression of GABAA currents was significantly less expressed when intracellular ATP was replaced by its analog adenosine 5'-O-(3-thiotriphosphate) and when the specific phosphatase 2B inhibitor cypermethrin was added intracellularly. The reduction of GABAA responses persisted after cessation of N-methyl-D-aspartate-mediated calcium influx, indicating a long-term action of N-methyl-D-aspartate on GABAA responses. Voltage-activated calcium currents did not affect GABAA responses under the experimental conditions applied. In conclusion, the data presented show that calcium influxes through N-methyl-D-aspartate receptor channels result in long-term suppression of GABAA receptor function in CA1 pyramidal cells. Intracellular mechanisms of N-methyl-D-aspartate-mediated reduction of GABAA conductances involve activation of phosphatase 2B and consecutive dephosphorylation of the GABAA receptor or a closely associated GABAA receptor-regulating enzyme. Possible mechanisms of such a distinct N-methyl-D-aspartate-dependent calcium signalling pathway in the dephosphorylation-dependent suppression or GABAA receptor function are discussed.
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572
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Jiang QX, Hu KS, Shi H. Interactions of both melittin and its site-specific mutants with bacteriorhodopsin of Halobacterium halobium: sites of electrostatic interaction on melittin. Photochem Photobiol 1994; 60:175-8. [PMID: 7938217 DOI: 10.1111/j.1751-1097.1994.tb05087.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Melittin and its site-specific mutants differentially delay the slow-decaying component of the photocycle intermediate M412 of bacteriorhodopsin in the purple membrane and the acetylated purple membrane whose several lysine residues are modified. This effect is attributed to the interaction of the total positive charges of melittin or its mutants with the total negative charges of bacteriorhodopsin. The effects of melittin and its mutants on the Triton X-100-solubilized bacteriorhodopsin monomers are somewhat complicated but are associated with their charges. These results show that there is electrostatic interaction between bacteriorhodopsin and melittin and that both N- and C-termini of melittin function as sites of the interaction, with Arg 22 and Arg 24 making a prominent contribution to the effective surface charge of melittin. Melittin, at certain concentrations, partially restores the decreased photoactivity of the bacteriorhodopsin monomers trapped in the Triton-lipid-protein mixed micelles, which suggests that melittin may compete with Triton X-100 for the binding sites on the bacteriorhodopsin monomers. Other kinds of interactions between bacteriorhodopsin and melittin are also indicated. The possible states of melittin in membranes are discussed.
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573
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Shi H, Verechaka G, Griffin A. Theory of the decay luminescence spectrum of a Bose-condensed interacting exciton gas. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:1119-1125. [PMID: 9975781 DOI: 10.1103/physrevb.50.1119] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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574
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Shi Y, Shi H, Ma S. [Molecular cytogenetic study of Turner's syndrome with the 45, X/46,X,r(?) karyotype]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1994; 16:218-21. [PMID: 7805169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Two small marker chromosomes were identified as X-derived ring chromosomes by using the high-resolution banding technique and in situ hybridization with a radioactively labelled human X-chromosome-specific satellite DNA probe. This procedure clearly determined the origin of the marker chromosome, which had been impossible using conventional cytogenetic techniques. The clinical significance of this work is briefly discussed.
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575
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Shi H, Teng CT. Characterization of a mitogen-response unit in the mouse lactoferrin gene promoter. J Biol Chem 1994; 269:12973-80. [PMID: 8175715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Lactoferrin is present in a variety of tissues and biological fluids; however, the amount differs significantly due to differential expressions. We have previously demonstrated that the mouse lactoferrin gene is regulated by estrogen through an estrogen-response DNA element located at -349, upstream from the transcription start site (+1). In this report, we characterized by deletion and mutation analyses a cluster of mitogen-response elements located between -80 and -40 of the mouse lactoferrin promoter. We demonstrated that the chimeric chloramphenicol acetyltransferase reporter constructs (the -103 to +1 sequence of the mouse lactoferrin gene) containing the mitogen-response unit of the lactoferrin gene were stimulated by cAMP, forskolin, 12-O-tetradecanoylphorbol-13-acetate, and epidermal growth factor/recombinant transforming growth factor-alpha (EGF/TGF-alpha) in a time- and dose-dependent manner. The sequence at position -52 to -40 (mLF-CRE) of the gene conferred transcriptional activation in the presence of forskolin, cyclic AMP, and 12-O-tetradecanoylphorbol-13-acetate in transiently transfected human endometrium carcinoma RL95-2 cells, whereas the region at -80 to -60 responded to EGF/TGF-alpha stimulation. Overexpression of the catalytic unit of protein kinase C or protein kinase A in the RL95-2 cells elevated the chloramphenicol acetyl-transferase activity of the reporter construct 5-6-fold. The mobility shift assay suggested that AP1 and CREB or related proteins participated in complex formation with the mLF-CRE, whereas different proteins bound to the EGF/TGF-alpha-response element.
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576
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Shi H, Teng C. Characterization of a mitogen-response unit in the mouse lactoferrin gene promoter. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)99971-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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577
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Jacobi K, Shi H, Gruyters M, Ertl G. Adsorbate-induced electronic modification of alkali-metal overlayers. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:5733-5736. [PMID: 10011540 DOI: 10.1103/physrevb.49.5733] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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578
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Grobecker R, Shi H, Bludau H, Hertel T, Greber T, Böttcher A, Jacobi K, Ertl G. Emission of exoelectrons during oxidation of Cs via thermal activation of a metastable O2- surface species. PHYSICAL REVIEW LETTERS 1994; 72:578-581. [PMID: 10056468 DOI: 10.1103/physrevlett.72.578] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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579
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Shi H, Cenedella RJ. Regional distribution of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and protein mass in the ocular lens. J Lipid Res 1993; 34:2177-82. [PMID: 8301236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We have attempted to map the regional distribution of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) enzyme activity and protein mass along the radial axis of the ocular lens. Because lens plasma membrane is extremely rich in cholesterol and the lens must synthesize this cholesterol, the activity of HMGR could be a key factor controlling lens membrane formation. Lenses of young rats were divided into discrete fractions by gradual dissolution in a tergitol-containing buffer; each fraction was then equated to a specific arc of the radius based upon its protein content. Aliquots of each fraction were assayed for HMGR enzyme activity and protein mass. Relative protein mass was quantitatively estimated by Western blotting using a monoclonal antibody to HMGR with immunoreactivity detected by enhanced chemiluminescence. Lens HMGR possessed a molecular mass of about 97 kDa and localized in the cell's insoluble fraction. Peak levels of both HMGR enzyme activity and protein mass were found in the outer 5% of the lens radius; levels of both decreased precipitously from there to the outer 10% radius mark. This distribution paralleled synthesis of the membrane's cholesterol, phospholipid, and intrinsic protein. We conclude that the abrupt cessation of plasma membrane synthesis in the ocular lens could involve loss of HMGR activity over a narrow arc of the lens radius, and that this activity loss is due to disappearance of enzyme protein.
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580
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Abstract
An automated structure-refinement program has been developed for X-ray powder diffraction data collected on disordered carbons. The program minimizes the difference between the observed and calculated diffraction profiles in a least-squares sense by optimizing model parameters analogously to the popular Rietveld refinement method. Unlike the Rietveld method, which is designed for crystalline materials, this program allows the quantification of the finite size, strain and disorder present in disordered carbon fibers and cokes. For example, the structural model used includes the probability of a random translation parallel to adjacent carbon layers as a refinable parameter describing turbostratic disorder. Other parameters are used to describe finite size, fluctuations in the spacing between adjacent layers, average lattice constants, background and other important quantities. The structural model, combined with the refinement program, acceptably describes the diffraction patterns from disordered carbons such as pitch heated near 823 K, cokes, fibers, heat-treated cokes and synthetic graphite.
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581
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582
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Xie B, Shi H, Chen Q, Ho CT. Antioxidant properties of fractions and polyphenol constituents from green, oolong and black teas. PROCEEDINGS OF THE NATIONAL SCIENCE COUNCIL, REPUBLIC OF CHINA. PART B, LIFE SCIENCES 1993; 17:77-84. [PMID: 7809277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Green, oolong and black teas were extracted with water, and then the water extracts were extracted separately with three types of solvent, chloroform, ethyl acetate and butanol, to obtain eight fractions. Major flavanol was extracted by EtOAc, while most of the alkaloid was in the chloroform fraction. Thearubigin was greatest in the butanol fraction, and most of the amino acid remained in the water fraction. All fractions were systematically analyzed by UV spectrophotometer and reverse phase HPLC for those important components existing in green tea, oolong tea, and black tea. The pure compounds of (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), free theaflavin, theaflavin monogallate-A, theaflavin monogallate-B, and theaflavin digallate were separated by LH-20 chromatography and reverse phase HPLC. All fractions and pure compounds were assayed for antioxidant activity and lipoxygenase inhibition activity. Flavanol showed very strong antioxidant activity and lipoxygenase inhibition.
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583
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Lane NE, Michel B, Bjorkengren A, Oehlert J, Shi H, Bloch DA, Fries JF. The risk of osteoarthritis with running and aging: a 5-year longitudinal study. J Rheumatol 1993; 20:461-8. [PMID: 8478853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Our purpose was to determine the 5-year longitudinal effects of running and aging on the development of radiographic and clinical osteoarthritis (OA) of the knees, hands and lumbar spine. Thirty-five running subjects and 38 controls, with a mean age of 63 years, were matched for age (+/- 2 years), years of education, and occupation; 33 matched pairs were constructed. All subjects underwent rheumatologic examination, completed questionnaires, and had radiographs taken of the hands, lateral lumbar spine, and knees in 1984 and in 1989. Five year radiographic results for both the runner and control groups showed OA progression for the knees, hands, and lumbar spine. In 1989, 10 (13%) of the 73 subjects fit American College of Rheumatology (ACR) criteria for clinical OA of the hand, and 9 subjects (12%) fit ACR criteria for OA of the knee. In summary, running did not accelerate the development of radiographic or clinical OA of the knees, but with aging, 13% of all subjects developed OA of the hands and 12% of all subjects developed OA of the knees.
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584
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Pride MW, Shi H, Anchin JM, Linthicum DS, LoVerde PT, Thakur A, Thanavala Y. Molecular mimicry of hepatitis B surface antigen by an anti-idiotype-derived synthetic peptide. Proc Natl Acad Sci U S A 1993; 89:11900-4. [PMID: 1361231 PMCID: PMC50665 DOI: 10.1073/pnas.89.24.11900] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Monoclonal antibody 2F10 is an "internal-image" anti-idiotype (anti-id) antibody capable of mimicking the group-specific "a" determinant of human hepatitis B surface antigen (HBsAg). By mRNA sequencing and computer-assisted molecular modeling of monoclonal antibody 2F10, we identified a 15-amino acid region of the heavy-chain hypervariable region that has partial residue homology with sequences of the "a" determinant epitopes of HBsAg. We have established that a linear 15-mer peptide from a contiguous region on the anti-id antibody can (i) generate anti-HBsAg-specific antibodies when injected into mice, (ii) prime murine lymph node cells for in vitro HBsAg-specific T-cell proliferative responses, and (iii) stimulate in vitro human CD4+ T cells that were primed in vivo to HBsAg by natural infection with hepatitis B virus or vaccination with a commercially available HBsAg vaccine. Significantly, this peptide could also stimulate CD4+ T cells of human hepatitis B virus carriers. We conclude that a 15-mer peptide derived from the anti-id sequence can duplicate the B- and T-cell stimulatory activity of the intact anti-id antibody and the antigen that is mimicked, HBsAg.
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585
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Shi H, Miller F, Miller K, Kim MH. The effect of platelet activating factor on different phases of murine in vitro fertilization. J Assist Reprod Genet 1992; 9:373-7. [PMID: 1472817 DOI: 10.1007/bf01203962] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Our purpose was to examine the effect of platelet activating factor (PAF) in different phases of mouse in vitro fertilization and optimal parameters that would enhance the fertilization rate. DESIGN AND SETTINGS Various PAF concentrations (10(-7) to 10(-5) M) were selected to investigate its effect on three phases of mouse in vitro fertilization (i.e., sperm capacitation, sperm/oocyte coincubation, and preimplantation embryo growth) in three experimental groups: (I) with PAF treatment in the first phase, (II) with PAF treatment adopted in the first and second phases, and (III) with PAF treatment implemented in all three phases. RESULTS The improvement of the fertilization rate in PAF treatment groups over the control group ranges from 6.5 to 19.0% (P < 0.05-P < 0.001). The highest enhancement of fertilization rate was achieved under the condition of PAF treatment (10(-6) M) through sperm capacitation and sperm/oocyte coincubation phases. CONCLUSION The PAF concentration of 10(-6) M in sperm capacitation and sperm/oocyte coincubation yielded the greatest improvement in fertilization. However, continuing PAF treatment after sperm/oocyte coincubation had no beneficial effect on fertilization and preimplantation development.
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586
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Abstract
METHODS. Twelve different types of Chinese teas, including green, semifermented, and black tea, were studied for their antioxidant activities and active components. Compositions of (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate, (-)-epigallocatechin gallate, and gallic acid were identified by fast atom bombardment-mass spectrometry and high-performance liquid chromatography-mass spectrometry and quantified by high-performance liquid chromatography. Antioxidant activities in lard were measured by the Rancimat method. RESULTS. The results showed that both yields of polyphenol extract and antioxidant activities varied with different tea processing methods. It was found that (-)-epigallocatechin gallate, (-)-epigallocatechin, and (-)-epicatechin gallate inhibited soybean lipoxygenase at the IC50 values ranging from 10 to 20 microM.
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587
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Liu R, Veal BW, Paulikas AP, Downey JW, Shi H, Olson CG, Gu C, Arko AJ, Joyce JJ. Electronic structure near EF in YBa2Cu3Ox for 6.35 <= x <= 6.9: A photoemission study. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 45:5614-5621. [PMID: 10000279 DOI: 10.1103/physrevb.45.5614] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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588
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Shi H, Griffin A. Transverse and longitudinal electromagnetic modes in metallic superlattices. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 44:11977-11985. [PMID: 9999334 DOI: 10.1103/physrevb.44.11977] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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589
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Shi H, Rezayi EH. Finite-size study of the excitation and thermodynamics of the two-dimensional spin-1/2 Heisenberg antiferromagnet: Comparison with spin-wave theory. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 43:13618-13621. [PMID: 9997200 DOI: 10.1103/physrevb.43.13618] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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590
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van Keulen H, Mertz PM, LoVerde PT, Shi H, Rekosh DM. Characterization of a 54-nucleotide gap region in the 28S rRNA gene of Schistosoma mansoni. Mol Biochem Parasitol 1991; 45:205-14. [PMID: 2038356 DOI: 10.1016/0166-6851(91)90087-m] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have analyzed 572 bp in the 28S rDNA of the human blood fluke Schistosoma mansoni which correspond to expansion segment 5 of domain IV as defined by Clark et al. for the Xenopus laevis 28S rRNA. S1 nuclease mapping and primer extension analysis comparing this region with the mature 28S rRNA indicate that there are 54 nucleotides present in the 28S rDNA which are absent from the mature rRNA. This defines a gap that creates two 28S rRNA subunits (28S alpha and 28S beta). Comparison of the S. mansoni sequence with rDNAs of other organisms which contain gaps in their 28S rRNA shows that the overall features are conserved except that the S. mansoni gap is less A + T-rich. The conserved features include: (1) the location of the gap within the 28S rRNA; (2) the predicted secondary structure of the gap, containing a stem-loop with a UAAU sequence within the loop; and (3) a conserved CGAAAGGG on the 3' side of the gap.
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591
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Veal BW, Paulikas AP, You H, Shi H, Fang Y, Downey JW. Observation of temperature-dependent site disorder in YBa2Cu3O7- delta below 150 degreesC. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 42:6305-6316. [PMID: 9994712 DOI: 10.1103/physrevb.42.6305] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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592
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Veal BW, You H, Paulikas AP, Shi H, Fang Y, Downey JW. Time-dependent superconducting behavior of oxygen-deficient YBa2Cu3Ox: Possible annealing of oxygen vacancies at 300 K. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 42:4770-4773. [PMID: 9996015 DOI: 10.1103/physrevb.42.4770] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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593
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Zhou C, Shi H, Liu W, Jin C, Gao H. Antiinflammatoiy effect of essential oil of abies nephrolepis (trautv.) maxim. Eur J Pharmacol 1990. [DOI: 10.1016/0014-2999(90)93813-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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594
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Shi H, Zhou C, Li Y, Wang G, Sun Y. [Anti-inflammatory effect of aconitines]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1990; 15:174-7, 192. [PMID: 2150749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Aconitines are the total alkaloids isolated from the main root of Aconitum carmichaeli. They have marked suppressive effect on the swelling of rat's hind paw induced by injections of fresh egg protein, carrageenin, histamine and 5-HT, on the mouse's ear oedema induced by bimethylphenyl, on the exudate and proliferation of granulation tissue of granuloma pouch induced by croton oil, on the leukocyte migration and on the contents of PGE in the exudate of the swelling hind paw induced by injecting carrageenin. Aconitines have been found useful in inhibiting significantly such immune inflammations as reversible passive Arthus reaction, rat's delayed skin hypersensitivity and adjuvant arthritis. They have also a noticeable analgesic effect.
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595
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Shaked H, Veal BW, Faber J, Hitterman RL, Balachandran U, Tomlins G, Shi H, Morss L, Paulikas AP. Structural and superconducting properties of oxygen-deficient NdBa2Cu3O7- delta. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 41:4173-4180. [PMID: 9994239 DOI: 10.1103/physrevb.41.4173] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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596
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Shi H. [Thinking about several problems of the research of our family planning strategy]. REN KOU YAN JIU = RENKOU YANJIU 1989:48-52. [PMID: 12159310] [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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597
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Shi H, Xu G, Shen Z. A retrospective study of oral mucosal diseases in three age groups. GERODONTICS 1988; 4:235-7. [PMID: 3271719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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598
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Shi H, Lewis DI, Coote JH. Effects of activating spinal alpha-adrenoreceptors on sympathetic nerve activity in the rat. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1988; 23:69-78. [PMID: 2902118 DOI: 10.1016/0165-1838(88)90168-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effects of several alpha-adrenoreceptor agonists and antagonists administered intrathecally at T10 level on renal sympathetic nerve activity (RSNA) were examined, in chloralose-urethane anaesthetised rats. Intrathecal noradrenaline (NA, 0.5-500 micrograms) produced one of 3 responses depending on dose, an inhibition of RSNA at low doses, an excitation of RSNA at high doses, or a biphasic effect. Intrathecal adrenaline (5-200 micrograms) was inhibitory in the main but some doses elicited poorly repeatable brief excitation followed by prolonged inhibition. Intrathecal methoxamine (ME; 2.5 ng-25 micrograms) caused a dose-dependent increase in RSNA (mean maximum response 27 +/- 0.5%). The excitatory effects of NA and ME were blocked (72% +/- 12%) by pretreatment with intrathecal prazosin (PRA, 20-200 ng) but not by yohimbine (YOH, 200 ng). Intrathecal guanabenz (GUA 3-15 micrograms) caused a dose-dependent inhibitory effect on RSNA (mean maximum 32% +/- 5%). The inhibitory effects of NA, adrenaline and GUA were blocked by pretreatment with intrathecal YOH (200 ng-2 micrograms). Intrathecal PRA (200 ng) had no effect on the inhibitory effects of NA and GUA. Intravenous administration of each of the adrenoreceptor agonists (apart from adrenaline), at similar doses to those given intrathecally, in most cases had no significant effect on RSNA; in a few cases the opposite effects to those produced by intrathecal administration were seen.
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