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Li H, Gao P, Qi H, Huei H, Wang C. [Study on relationship between proto-oncogene expression of c-fos and c-myc in airway, lung tissue and asthma in guinea pigs]. ZHONGGUO YING YONG SHENG LI XUE ZA ZHI = ZHONGGUO YINGYONG SHENGLIXUE ZAZHI = CHINESE JOURNAL OF APPLIED PHYSIOLOGY 1997; 13:356-8. [PMID: 10322972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
In order to investigate the mechanism of the attack of asthma, the authors examined the proto-oncogene expression of c-fos and c-myc in the airway and lung tissue of the ovalbumin-induced asthmatic guinea pigs by using Dot-blot. Northern-blot and immunohistochemical techniques. There was a baseline expression of c-fos and c-myc in the controls, whereas the mRNA expression of c-fos and c-myc increased much more significantly in asthmatic guinea pigs, it reached maximum at 30 min after the onset of asthma and it was in a time dependant manner. The inducement could be inhibited partially by dexamethasone. Immunohistochemical investigation showed that c-fos and c-myc was distributed mainly in epithelial cells of the airway. The staining was more intensive in the asthmatic guinea pigs than in the controls. The results suggest that the increase in proto-oncogene expression of c-fos and c-myc may be related to the attack of asthma.
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Yan BX, Sun YQ, Gao P. Intrinsic fluorescence in endoglucanase and cellobiohydrolase from Trichoderma pseudokiningii S-38: effects of pH, quenching agents, and ligand binding. JOURNAL OF PROTEIN CHEMISTRY 1997; 16:681-8. [PMID: 9330226 DOI: 10.1023/a:1026354403952] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To gain further insight into the difference in substrate specificity between endoglucanase and cellobiohydrolase, the intrinsic fluorescence properties of cellobiohydrolase I (CBH I) and endoglucanase I (EG I) from Trichoderma pseudokiningii S-38 were investigated. The results for the spectral characteristics, ligand binding and fluorescence quenching suggest that the fluorescence of two enzymes comes from tryptophan residues, and that tryptophan residue(s) may be involved in the function of the two enzymes. The results also suggest that the binding tryptophan in EG I may be more exposed to solvent than that in CBH I. This interpretation is supported by the observations that the effects of pH upon the fluorescence of EG I are greater than that of CBH I; spectral shifts are different in EG I and CBH I under various conditions, and fluorescence lifetime changes caused by cellobiose binding are larger for EG I than for CBH I.
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Zhou Y, Luo L, Liu X, Gao P, Su Y. [MA891--an established spontaneous mouse mammary adenocarcinoma cell line and its immunologic characteristics]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1997; 19:273-7. [PMID: 10453566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
OBJECTIVE To characterize the immunologic properties of an established mouse mammary tumor cell line MA891. METHODS From a spontaneous mouse mammary adenocarcionma (TA2 MA891) of TA2 mouse origin, an in vitro passaged cell line MA891 was maintained in RPMI1640 with 10% new born calf serum. The immunogenecity of MA891 was studied by classical tumor transplantation rejection assay, generation of cytotoxic T lymphocytes (CTL) by syngeneic secondary mixed lymphocyte-tumor cell culture (MLTC) and cytotoxic assay of tumor infiltrating lymphocytes (TIL). RESULTS MA891 maintained the high metastatic potential of the parental TA2 MA891 tumor passaged in vivo. Transplantation rejection studies indicated that amputation of a hind limb with growing tumor in the footpad did not protect the mice from a second subcutaneous challenge of the same tumor. The cytotoxic activities of both CTL and TIL were shown to be very weak. CONCLUSION MA891 is a mouse tumor of very low immunogenecity. It can be used as a mouse tumor model for studying cancer metastasis in humans.
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Li X, Gao P. CMC-liquefying enzyme, a low molecular mass initial cellulose-decomposing cellulase responsible for fragmentation from Streptomyces sp. LX. J Appl Microbiol 1997; 83:59-66. [PMID: 9246771 DOI: 10.1046/j.1365-2672.1997.00191.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
LX, newly isolated from soil, was shown to secrete a carboxylmethylcellulose (CMC)-liquefying enzyme that cleaves the CMC chains, releasing negligible reducing terminals. The new enzyme, named component C2, was purified to homogeneity by dialysation. It has a molecular mass of 9.8 kDa. The pH optimum of the enzyme activity is 6.4 and its temperature optimum is 50 degrees C. It retains full activity at pH 4-6.4 upon incubation at 50 degrees C for 30 min. The enzyme has significant fragmentation activity on filter paper despite the absence of weight loss, release of reducing sugars and depolymerization during incubation with filter paper. The one-electron oxidative reaction is shown not to participate in the fragmentation of filter paper by enzyme C2.
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Schoof E, John MR, Arndt B, Gao P, Theuer D, Sieg A, Schmidt-Gayk H. Solid phase competitive luminescence immunoassay for immunoglobulin A in faeces: development and clinical validation. Clin Chim Acta 1997; 261:1-17. [PMID: 9187500 DOI: 10.1016/s0009-8981(96)06510-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We describe a new simple solid-phase competitive luminescence immunoassay (LIA) for the determination of immunoglobulin A (IgA) in faeces. The assay utilizes an anti-alpha-chain IgA antibody which is coated to polystyrene beads and acridinium ester-labelled human IgA as tracer and, therefore, measures both monomeric and polymeric IgA. Dilution recovery of an internal standard was 96, 100 and 103%. Interassay and intra-assay coefficients of variation (C.V.) ranged from 4.5 to 12.9%. The upper limit of normal of faecal IgA in 122 healthy controls was found to be 300 mg/l IgA (mean 73 mg/l, specificity of 99.2%). Patients with inactive Crohn's disease (Crohn's disease activity index (CDAI < 150, n = 14) had faecal IgA values up to 3317 mg/l (mean 1073 mg/l; P < 0.0001). In the active group (CDAI > 150, n = 26) faecal IgA values ranged from 49 to 4094 mg/l (mean 1253 mg/l; P < 0.0001). Patients with ulcerative colitis were divided into a group with active disease (n = 18) and a remission group (n = 16) with values up to 1843 mg/l faecal IgA (man 486 mg/l; P < 0.0032) and up to 602 mg/l faecal IgA (mean 176 mg/l; P < 0.4833), respectively. We also studied patients with non-inflammatory diseases of the gut with this assay. This LIA has proved to be a reliable method for the determination of elevated faecal IgA concentrations and for the detection of pathological findings in the gastrointestinal tract, especially in Crohn's disease.
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Johnson G, Nguyen KN, Liu Z, Gao P, Pasqualini R, Okada RD. Planar imaging of 99mTc-labeled (bis(N-ethoxy, N-ethyl dithiocarbamato) nitrido technetium[V]) can detect resting ischemia. J Nucl Cardiol 1997; 4:217-25. [PMID: 9199259 DOI: 10.1016/s1071-3581(97)90082-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND (99m)Tc-labeled (bis(N-ethoxy, N-ethyl dithiocarbamato) nitrido technetium(V)) ([99m]TcN-NOET) is a new lipophilic, neutral-charge cardiac perfusion imaging agent that demonstrates apparent redistribution in animal models and humans. The purpose of this study was to determine whether the kinetics of (99m)TcN-NOET are suitable for the detection of resting ischemia. METHODS AND RESULTS Microspheres were injected at baseline and simultaneously with (99m)TcN-NOET after a 90% reduction in resting flow in the left circumflex coronary artery in six open-chest canine experiments. The relationship of flow and activity early after injection was determined in one experiment by termination at 10 minutes. The flow ratio (left circumflex/left anterior descending coronary artery) after stenosis fell significantly (0.87 +/- 0.04 vs 0.46 +/- 0.04; p < 0.05). The end-tissue (99m)Tc ratio (0.78 +/- 0.05) was significantly higher than the flow ratio at injection (0.46 +/- 0.04; p < 0.05), indicating substantial redistribution. In vivo imaging was conducted during 2 hours in five experiments, followed by ex vivo imaging. Myocardial clearance from 10 minutes onward was biphasic in left anterior descending and monophasic in left circumflex coronary arteries. Myocardial clearance from 10 to 60 minutes was delayed in left circumflex (35.5% +/- 8.1%) versus left anterior descending coronary arteries (49.2% +/- 8.6%; p < 0.05). No significant difference was observed from 60- to 120-minute clearance. Five of five experiments demonstrated initial defects and complete fill-in at 90 to 120 minutes by qualitative assessment. Quantitation of ex vivo images confirmed significant redistribution. CONCLUSIONS Resting ischemia caused by moderate to severe stenosis can be detected on scans with (99m)TcN-NOET. Redistribution was near complete in this model by 90 to 120 minutes. (99m)TcN-NOET is a promising new agent for the detection of coronary artery disease in viable myocardium and warrants further investigation.
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Gao P, Dillon HK, Farthing WE. Development and evaluation of an inhalable bioaerosol manifold sampler. AMERICAN INDUSTRIAL HYGIENE ASSOCIATION JOURNAL 1997; 58:196-206. [PMID: 9075310 DOI: 10.1080/15428119791012847] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This paper describes the development and evaluation of an inhalable bioaerosol manifold sampler for the collection of replicate samples over sequential sampling periods. Wind tunnel experiments at wind velocities < or = 0.6 m/sec (< or = approximately 120 ft/min) and at a sampling velocity of 0.6 m/sec yielded sampling efficiencies within 10% of the American Conference of Governmental Industrial Hygienists' inhalable curve up to particle diameters of about 18 microns and efficiencies within 18% for diameters up to 26 microns. At wind velocities > or = 0.6 m/sec, a sampling velocity of 0.8 m/sec yielded efficiencies that were within 15% of the inhalable curve up to diameters of about 22 microns and within 20% for diameters up to 25 microns. Microscopic counts of 15.6-micron and 25.6-micron monodisperse polystyrene beads aerosolized in the wind tunnel and collected with the manifold sampler yielded precise concentrations (pooled CV = 9.0 and 5.3%, respectively) averaging 115% and 92%, respectively, of measurements with the APS Model 3310 aerodynamic particle sizer. Field tests in a cotton dust environment demonstrated the ability to generate a time/concentration profile of fungal spores similar to that indicated for cotton dust levels determined with horizontal elutriators. Cotton dust was sampled efficiently while cotton fibers were excluded. Field tests on a dairy farm indicated no statistically significant bias (p = 0.72) between spore concentrations determined with the manifold sampler and concentrations determined through a central test port.
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Gao P, Lu Y, Ge X. [TGF beta 1 on murine tumor growth following direct intratumoral injection of plasmid DNA]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1997; 19:93-5. [PMID: 10743068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
OBJECTIVE To investigate TGF beta 1 gene expression and its effect on murine tumor growth following direct intratumoral injection of naked plasmid DNA encoding human TGF beta 1. METHODS LM3 murine lung adenocarcinoma cells, were injected subcutaneously to T739 mice and grew to tumor nodules in 2 weeks, Multiple direct intratumoral injections of plasmid DNA, PMAM-neo-TGF beta 1, were given and were compared with saline or vector plasmid administration groups. The growth of tumor was observed till the 8th week when the mice were killed for Northern blot analysis and histopathological study of tumoral tissue. RESULTS The growth of tumor was boosted in the TGF beta 1 gene treated mice as compared with the control groups, whereas there was no significant difference in the metastatic behavior. Northern blot showed efficient expression of TGF beta 1 mRNA in the treated group. CONCLUSION TGF beta 1 may stimulate tumor growth in vivo through certain mechanisms. Direct intratumoral injection of nude plasmid DNA may be a promising gene transfer strategy in vivo.
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Li X, Gao P. Isolation and partial properties of cellulose-decomposing strain of Cytophaga sp. LX-7 from soil. J Appl Microbiol 1997. [DOI: 10.1111/j.1365-2672.1997.tb03299.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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261
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Gao P, Malbon CC. Differentiation of F9 teratocarcinoma stem cells to primitive endoderm is regulated by the Gialpha2/Gsalpha axis via phospholipase C and not adenylylcyclase. J Biol Chem 1996; 271:30692-8. [PMID: 8940046 DOI: 10.1074/jbc.271.48.30692] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Morphogen-induced decline in Gialpha triggers F9 teratocarcinoma stem cells to progress to primitive endoderm via activation of protein kinase C and mitogen-activated protein kinase (Gao, P., and Malbon, C. C. (1996) J. Biol. Chem. 271, 9002-9008). Constitutive expression of Gialpha2 blocks, whereas expression of Gsalpha provokes, progression to primitive endoderm, permitting identification of the effectors of the response-utilizing chimera created between Gialpha2 and Gsalpha. N-terminal substitution of Gsalpha with Gialpha2 sequence to create chimera Gialpha2 (1-54)/Gsalpha produced a chimera that activated adenylylcyclase but abolished progression to primitive endoderm and activation of phospholipase C. C-terminal substitution of Gsalpha with Gialpha2 sequence to Gsalpha/Gialpha2 (320-355) enhanced the ability of Gsalpha to promote progression. The Q205L-activated mutant of Gialpha2 suppresses, whereas the G225T-activated mutant of Gsalpha strongly activates phospholipase C and progression in these cells. The N-terminal region of Gsalpha (residues 62-86) appears to act as a dominant switch for the Gsalpha- (activation) versus Gialpha2- (suppression) mediated control of phospholipase C and progression to primitive endoderm.
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Gao P, Thornton-Manning JR, Pegram RA. Protective effects of glutathione on bromodichloromethane in vivo toxicity and in vitro macromolecular binding in Fischer 344 rats. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1996; 49:145-159. [PMID: 8874533 DOI: 10.1080/009841096160899] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Bromodichloromethane (BDCM), a carcinogenic water disinfection by-product, has been shown to be metabolized to intermediates that covalently bind to lipids and proteins, and this binding has been associated with trihalomethane-induced renal and hepatic toxicity. In this study, the effects of glutathione (GSH) on in vivo BDCM toxicity and in vitro BDCM macromolecular binding were evaluated. The in vivo toxicity of BDCM in animals pretreated with buthionine sulfoximine (BSO, a glutathione synthesis inhibitor) and in untreated male Fischer 344 rats was investigated. In another experiment, covalent binding to protein and lipid was quantified after [14C]BDCM was incubated with hepatic microsomal and S9 fractions and renal microsomes from F344 rats, under aerobic and anaerobic conditions, with and without added GSH. After oral dosing with BDCM, the BSO-pretreated animals had greatly increased levels of serum indicators of hepatotoxicity and serum and urinary indicators of nephrotoxicity compared to those in animals dosed solely with BDCM. Histopathological examination revealed that hepatic necrosis was more severe than renal necrosis in the BSO-treated rats. When GSH was added to an aerobic incubation, protein binding was decreased in hepatic microsomal and S9 fractions by 92 and 83%, respectively. GSH also decreased lipid binding by 55% in hepatic microsomal incubations carried out under anaerobic conditions. Addition of GSH decreased renal microsomal protein (aerobic) and lipid binding (anaerobic) by 20 and 43%, respectively. These data indicate that GSH is an important protective factor in the toxicity associated with BDCM.
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Gao P. Comparison of cyclic delta-opioid peptides with non-peptide delta-agonist spiroindanyloxymorphone (SIOM) using the message-address concept: a molecular modeling study. J Comput Aided Mol Des 1996; 10:327-36. [PMID: 8877704 DOI: 10.1007/bf00124502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Based upon the message-address concept, this molecular modeling study used the delta-selective agonist spiroindanyloxymorphone (SIOM) as a molecular template for a conformational search and analysis of delta-selective opioid peptides. It was assumed that the tyramine moiety plays the same role for delta-opioid receptor recognition in both peptide and non-peptide ligands. Using 20 reported low-energy conformations of Tyr-cyclo[D-Cys-D-Pen]-OH (JOM-13) for comparison, the geometrical relationship of the two aromatic rings present in SIOM was used for the identification of potential active conformations of JOM-13, from which two delta-receptor-binding models (I and II) were constructed. Models I and II differ from each other in the arrangement of the peptide backbones. To evaluate the two models, a conformational search of two other known delta-selective ligands, [D-Pen2,D-Pen5]enkephalin (DPDPE) and [D-Pen2,L-Pen5]enkephalin (DPLPE) was performed, using the geometrical relationship of the two aromatic rings defined in the two receptor-binding models as a molecular template. Among the conformations generated from the molecular simulation, low-energy conformers of DPDPE and DPLPE conforming to models I and II were identified. Unlike model I, conformers of DPDPE and DPLPE that fit model II contain a cis amide bond in the Gly3 residue.
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Gao P, Meury RH. Swelling of hydroxypropyl methylcellulose matrix tablets. 1. Characterization of swelling using a novel optical imaging method. J Pharm Sci 1996; 85:725-31. [PMID: 8818997 DOI: 10.1021/js950458c] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A novel optical image analysis method was developed to examine the dynamic swelling behavior of hydroxypropyl methylcellulose (HPMC)-based matrix tablets in situ. In addition to providing precise determinations of apparent gel layer thickness and the tablet dimension, this method is also capable of estimating the HPMC concentration profile across the gel layer. The intensity of light scattered from HPMC gels was found to depend on polymer concentration. A mathematical model that describes the relationship between the scattered light intensity and HPMC concentration was derived from Rayleigh scattering theory coupled with the hypothesis that the turbidity of the gel is an exponential function of polymer concentration. The swelling behavior of a matrix tablet containing 80% HPMC, 17% lactose, and 2.5% adinazolam mesylate is characterized. The data reveal that as the matrix swells, the polymer concentration profiles, as well as the gel layer thicknesses, develop equally in both the axial and radial directions. In addition, the expected dominant axial expansion of the tablet was also observed. This optical image method is generally applicable to in situ characterization of the swelling behavior of polymer matrix-based tablets which are commonly used as extended-release dosage forms.
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Gao P, Skoug JW, Nixon PR, Ju TR, Stemm NL, Sung KC. Swelling of hydroxypropyl methylcellulose matrix tablets. 2. Mechanistic study of the influence of formulation variables on matrix performance and drug release. J Pharm Sci 1996; 85:732-40. [PMID: 8818998 DOI: 10.1021/js9504595] [Citation(s) in RCA: 129] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We characterized the effect of hydroxypropyl methylcellulose (HPMC)/lactose ratio and HPMC viscosity grade (molecular weight) on solute release and swelling of matrix tablets. We used a semiquantitative optical imaging method to monitor the swelling of matrices with HPMC content from 20% to 80% (w/w) and four viscosity grades. Several aspects of the swelling process common to all formulations were revealed: (i) swelling is anisotropic with a preferential expansion in the axial direction, (ii) swelling is isotropic with respect to the gel layer thickness and composition in both axial and radial directions, (iii) the gel layer develops in three stages, and (iv) water penetration is Fickian in nature and essentially constant for all formulations. We monitored simultaneously drug, lactose, and HPMC release. Lactose and drug release rates were superimposed, indicating a similar diffusional release mechanism and no interaction with HPMC. The strong dependence of HPMC release on viscosity grade is explained on the basis of the concept of polymer disentanglement concentration. We analyzed drug release rates using a model for a reservoir-type release system that incorporates swelling kinetics. HPMC/lactose ratio modulates drug release rate by altering drug diffusivity, a function of gel composition. In contrast, HPMC viscosity grade impacts matrix dissolution and gel layer thickness development below a critical molecular weight. For slowly dissolving matrices containing high viscosity grade (> 4000 cps) HPMC, similar drug release rates are observed mainly due to the same drug diffusivity as a result of the identical gel composition and thickness. For fast dissolving matrices (< or = 100 cps) swelling inhomogeneity is proposed as being responsible for a higher apparent drug diffusivity and release rate.
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Gao P. Determination of the composition of delavirdine mesylate polymorph and pseudopolymorph mixtures using 13C CP/MAS NMR. Pharm Res 1996; 13:1095-104. [PMID: 8842052 DOI: 10.1023/a:1016027212156] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE The application of solid-state nuclear magnetic resonance for the quantitation of relative amounts of delavirdine mesylate (DLV-M) polymorph and/or pseudopolymorph in their binary mixtures is presented. METHODS 13C CP (cross-polarization)/MAS (magic angle spinning) NMR techniques were employed for quantitation. RESULTS 13C CP/MAS NMR spectra of three DLV-M solid forms (VIII, XI, and XII) revealed distinct differences in chemical shifts and peak splitting characteristics. Resonances of isopropyl methyl carbons of DLV-M were diagnostic of each form; resonance intensities were utilized to determine the composition of two series of DLV-M solid form mixtures (VIII and XI; XII and XI) over a dynamic concentration range (1-50%). The empirical detection limit of form VIII, or XII, in a dominant form XI environment was about 2-3% (w/w). Quantitations were obtained using appropriate analytical procedures, which took into account the differences of TCH and T1pH between the two forms. Quantitative results obtained using either the peak area or peak height were examined, and, in general, were satisfactory. CONCLUSIONS The methodology and analytical procedure developed in this study are generally applicable to quantitative analysis using 13C CP/MAS NMR for pharmaceutical solids, including bulk drug substances, and dosage forms. Reliable measurement of NMR relaxation times (T1pH) and CP rate constants (TCH) of individual forms is a critical component in this application.
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Gao P, Malbon CC. Morphogen-induced decline in Gialpha2 triggers F9 teratocarcinoma stem cell progression via phospholipase C and mitogen-activated protein kinase. J Biol Chem 1996; 271:9002-8. [PMID: 8621547 DOI: 10.1074/jbc.271.15.9002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The linkage between Gialpha2 and morphogen-induced promotion of F9 embryonic teratocarcinoma stem (F9 stem) cells to primitive endoderm was explored using probes of the mitogen-activated protein (MAP) kinase network. The morphogen-induced decline in Gialpha2 is shown to trigger activation of phospholipase C, thereby activating protein kinase C, MAP kinase, and cell progression to primitive endoderm. In the absence of retinoic acid, reduction-of-function mutants (Gialpha2-deficient) display the effects of morphogen, i.e. activation of phospholipase C, protein kinase C, MAP kinase, and progression to primitive endoderm. Gain-of-function mutants (expressing the Q205L activating-mutation of Gialpha2) displayed no activation of phospholipase C, protein kinase C, MAP kinase and no progression to primitive endoderm, even in the presence of retinoic acid. Selective inhibitors of protein kinase C, like the gain-of-function mutations, effectively block morphogen-induced progression to primitive endoderm. Morphogen triggers F9 stem cell progression by triggering Gialpha2 loss and thereby activation of downstream elements, including protein kinase C and MAP kinase.
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Li X, Gao P. Isolation and partial characterization of cellulose-degrading strain of Streptomyces sp. LX from soil. Lett Appl Microbiol 1996. [DOI: 10.1111/j.1472-765x.1996.tb01145.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Qy Y, Gao P, Wang D, Zhao X, Zhang X. Production, characterization and application of the cellulase-free xylanase from Aspergillus niger. Appl Biochem Biotechnol 1996; 57-58:375-81. [PMID: 8669904 DOI: 10.1007/bf02941716] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effects of carbon source on xylanase and cellulase production were studied. The extract of steam-exploded corn stover was found to be the best raw material for producing cellulase-free xylanase. The xylanolytic enzymes of Aspergillus niger An-76 were purified by chromatography, and the properties of the four purified components were analyzed. When the enzyme was used to treat the birch Kraft pulp, and followed by a subsequent CEH bleaching, a brightness of 6.8% SBD more than that of the untreated one using the same chlorine dosage, or a saving of nearly 50% of chlorine consumption with the same brightness, was realized.
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Li X, Gao P. Isolation and partial characterization of cellulose-degrading strain of Streptomyces sp. LX from soil. Lett Appl Microbiol 1996; 22:209-13. [PMID: 8852349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A new bacterium, Streptomyces sp. LX, was isolated from soil, which was aerobic Gram-positive and could decompose crystalline cellulose completely. Endo-cellulase with CMC-liquefying activity was detected when alpha-cellulose, Avicel, Whatman CF11 or CMC was used as carbon source, and its production varied with nature of the carbon source. Only traces of reducing sugar were found in cultures during incubation. This strain could produce FPase, beta-glucanase and short fibre generating activity. Exo- and endo-cellulase were detected in cultures by measuring formation of total sugar but were not detected by determining release of reducing sugar.
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Gao P, Schmidt-Gayk H, Dittrich K, Nolting B, Maier A, Roth HJ, Seemann O, Reichel H, Ritz E, Schilling T. Immunochemiluminometric assay with two monoclonal antibodies against the N-terminal sequence of human parathyroid hormone. Clin Chim Acta 1996; 245:39-59. [PMID: 8646814 DOI: 10.1016/0009-8981(95)06171-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We have developed an immunochemiluminometric assay (ICMA) with two monoclonal antibodies for the N-terminal sequence of human parathyroid hormone (hPTH). One monoclonal antibody (A1-70) was physically adsorbed onto polystyrene beads, the other (B1-70) was labelled with acridinium ester and synthetic hPTH (1-38) was used as standard. This assay has cross-reactions with synthetic hPTH (1-34) and hPTH (1-84) but no cross-reactions with hPTH (4-16), (28-48), (39-84), (44-68), (53-84) and hPTH-rP (1-86). The assay detection limit is 0.4 pmol/l. The normal range is 1.3-12 pmol/l based on 72 normal volunteers. About 91% of study patients (n = 58) with surgically proven primary hyperparathyroidism (1 degree HPT) had PTH values above normal and one of them showed a low normal intact PTH value but elevated PTH values with use of this assay. After immunoabsorption of plasma samples from patients with secondary hyperparathyroidism (2 degrees HPT) on hemodialysis with polystyrene beads containing antibodies against hPTH (39-84), some patients still showed significant amounts of PTH in this new ICMA but not intact PTH. The data reveal that significant amounts of amino-terminal immunoreactive PTH fragments rarely exist in 1 degree HPT but are present in some patients with 2 degrees HPT. The major advantage of this assay is to measure both amino-terminal PTH fragments and intact PTH with no interference from carboxy-terminal PTH fragments because two anti-N-terminal hormone sequence monoclonal antibodies are used.
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Ai Y, Meng F, Gao P, Wang Z. An attempt on using the method of R-Q double-factor analysis to identify and group fusants. CHINESE JOURNAL OF BIOTECHNOLOGY 1996; 12:31-37. [PMID: 8877112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A subsequent numeric taxonomy method for identifying and grouping the fusants was explored on the basis of characterization of the protein profiles of the fusants. By these two means, several typical excellent candidates of recombinants could be searched out quickly. Among the fusants from a definite fusion-cross, the different sister-strains were regarded as the samples of observation (n = N), the positions of the all bands of protein profiles as the objects (p = P), and the photometer-scanning area of the specific band as the experimental value (X) (zero was taken when the specific band of a certain strain was absent). The genetic multirelationships among the inter- and intra-sister-strains in terms of the positions and contents of the protein bands after fusion recombination occurred from this definite fusion-cross could therefore be determined on the same orientational factor-plate by using the computer program of the R-Q double-factor method to analyze this data matrix (Xnxp). These sister-strains could then be identified and grouped from the deduced heredity relationship between the fusants and parents.
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Abstract
The rat's mystacial vibrissae are active during exploratory and discriminative behaviors, with individual vibrissae serving as elements in a receptive array scanned across object surfaces. To facilitate neurobehavioral analysis of this sensorimotor system, we have developed an experimental paradigm that confines vibrissa movements to a defined physical location, makes possible on-line monitoring of "whisking" activity, and brings such activity under associative control using operant conditioning procedures. Rats were secured, and movements of an identified bilaterally homologous pair of vibrissae (right and left gamma straddlers) were detected by laser-based photodetectors. Subjects were maintained on a water deprivation schedule, and whisker movements were monitored during adaptation to the test situation and after the clipping of other vibrissae on both sides of the snout. Rats were reinforced with water delivery for emitting vibrissa movements in the presence of a conditioned stimulus (tone) whose presentation was made contingent upon a prior period of nonwhisking. The rate and temporal distribution of vibrissa movements were brought under experimental control by means of interval and ratio reinforcement schedules. Although the procedures provide minimal information about the kinematics or topography of conditioned vibrissa movements, they permit the investigator to manipulate response parameters normally under the voluntary control of the animal in a preparation amenable to neurophysiological analysis.
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Chen K, Zhou WQ, Gao P. [Clinical study on the effect of shuxuening tablet in treatment of coronary heart disease]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1996; 16:24-6. [PMID: 8732126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Shuxuening was made of extract of Folium Ginkgo, the Shuxuening tablet No. 2 was a pure extract and No. 1 was a crude extract. Forty-six coronary heart disease patients were divided randomly into two groups according to the ratio of 2:1, Shuxuening tablet No. 1 and No. 2 were given to the two groups respectively. Results showed that both of them could alleviate the symptom of angina, the total effective rate of 2 groups were 60.00% and 83.87%, there was no significant difference between the two groups. But for the angina of middle and severe degree, the total effective rate of No. 2 was 83.33%, while that of No. 1 was 33.33%, the difference was significant (P < 0.01). They could also improve the abnormal electrocardiogram, the total effective rate of two groups were 60.00% and 74.19%, no significant difference between them was found. The two drugs could decrease the blood lipid as well.
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Zhou WQ, Gao P, Xie YM. [Clinical and laboratory studies of effect of longevity-antihypertensive-mixture on elderly hypertension with kidney deficiency]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1995; 15:532-5. [PMID: 8704439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
UNLABELLED Longevity-Antihypertensive-Mixture (LAM) is a Chinese herbal drug, which could tonify Kidney in treating the hypertension with Kidney Deficiency in aged patients. RESULTS 302 patients were randomly divided into three group: The treated group was subdivided into group I (107 Kidney Yin Deficiency patients) and group II (96 non-Kidney Yin Deficiency cases) and group III (99, control group). After treatment of LAM for 8 weeks, the rate of normalizing the blood pressure was 92.52% in group I while in group II, it was 84.43%, the symptoms were also significantly alleviated, and in group III, the rate was 70.71% only. The aorta compliance in group I significantly improved after LAM treatment (P < 0.025), the quality index of left ventricle reduced in treated group, and there was significant difference between treated and control groups. After treatment, LAM could shorten the length of extracorporal thrombus in group. The study showed that LAM could treat hypertension through LAM, administration with good effect.
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Gao P, John MR, Schmidt-Gayk H, Arndt B, Scheida M, Theuer D. Solid-phase competitive luminescence immunoassay for lysozyme in faeces. Clin Chim Acta 1995; 239:167-77. [PMID: 8542654 DOI: 10.1016/0009-8981(95)06112-q] [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: 01/31/2023]
Abstract
We have developed a new simple solid-phase luminescence immunoassay (LIA) for the determination of faecal lysozyme. The assay utilises a polyclonal capture antibody coated to polystyrene beads and acridinium ester-labelled human lysozyme as tracer. Samples are incubated with polystyrene beads and tracer overnight at 4 degrees C. After a thorough washing step, emitted light is measured by an automated luminometer for 2 seconds. The standard curve uses five standards ranging from 0.025 to 6.4 mg/l. The method has a sensitivity of 0.02 mg/l. Dilution recoveries for three samples were 88, 104 and 108%. Intraassay coefficients of variation (CV, n = 24) were 10.1% and 11.7% for a healthy control and a patient sample; interassay CV (n = 16) were 6.7% and 13.1% for the same healthy control but another patient sample. The normal range of faecal lysozyme in 80 healthy controls was found to be 0.02-1 mg/l (97.5 percentile) with a median of 0.28 mg/l. Fifty-three patients with Crohn's disease had faecal lysozyme values ranging from 0.16 to 100.7 mg/l with a median of 1.75 mg/l, and 30 patients with ulcerative colitis showed levels between 0.09 and 118 mg/l with a median of 1.11 mg/l. The assay has proved useful for differentiating healthy individuals from those with inflammatory bowel disease and might be a valuable tool for diagnosing or evaluating inflammatory bowel disease.
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Gao P, Fagerness PE. Diffusion in HPMC gels. I. Determination of drug and water diffusivity by pulsed-field-gradient spin-echo NMR. Pharm Res 1995; 12:955-64. [PMID: 7494815 DOI: 10.1023/a:1016293911499] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
PURPOSE This work describes diffusivity measurements of drug (adinazolam mesylate) and water in a variety of solutions including polymer gels. METHODS Pulsed-field-gradient spin-echo (PFGSE) NMR methods were employed to measure the diffusivity. RESULTS In binary component solutions, adinazolam diffusivity is generally found to exhibit an exponential dependence on the concentration of the viscosity-inducing agent (VIA), which is glucose, lactose, maltoheptaose, hydroxypropyl methylcellulose (HPMC) or drug itself. An increasing obstruction power to drug diffusion from glucose to HPMC is observed, which can be related to the polymerization degree of the VIA. In contrast, adinazolam diffusivity in HPMC gels shows little dependence upon the polymer viscosity grades examined (K100LV, K4M, and K15M). The temperature dependence of adinazolam diffusivity in dilute VIA solutions reveals that the diffusion barrier for the drug is similar to that for self-diffusion of water. CONCLUSIONS The retarding effect from the VIA for drug diffusion is concluded to be primarily associated with a steric obstruction mechanism. In multicomponent gels with varied concentrations of drug, lactose and HPMC, the drug diffusivity can be approximately described as an exponential function of the summation of the products of the proportionality constant (Ki) and concentration for each VIA component. In contrast, water diffusion behavior shows an universal exponential dependence upon the VIA concentration and small dependence upon the nature of the VIA. The interpretation of the diffusivity data is discussed and compared to two existing diffusion models (Yasuda and Mackie-Meares models).
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Gao P, Nixon PR, Skoug JW. Diffusion in HPMC gels. II. Prediction of drug release rates from hydrophilic matrix extended-release dosage forms. Pharm Res 1995; 12:965-71. [PMID: 7494816 DOI: 10.1023/a:1016246028338] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
PURPOSE A mathematical model is described for the prediction of the relative change in drug release rate as a function of formulation composition for HPMC-based extended-release (ER) tablets of adinazolam mesylate and alprazolam. METHODS The model is based on the equation derived by Higuchi for the diffusional release of soluble drugs from polymeric matrices and on our recent measurements of the concentration dependency of adinazolam diffusivity in dilute HPMC gels and solutions. The assumptions made in applying the model include (i) that diffusion is the sole mechanism of drug release (i.e. swelling kinetics are ignored), and (ii) that the surface area-to-volume ratio and concentrations of adinazolam, lactose and HPMC in the gel layer are proportional to that of the dry tablet. RESULTS Reasonable correlations were obtained between the experimental drug release rate ratios and the predicted drug release rate ratios for ER adinazolam mesylate (R2 = 0.82) and low-dose (0.5 mg) ER alprazolam tablets (R2 = 0.87). The predictive power for a 6-fold higher dose of ER alprazolam tablets was not as good (R2 = 0.52). CONCLUSIONS These results are consistent with previous knowledge of the release mechanisms of these formulations. ER adinazolam mesylate and ER alprazolam 0.5 mg exhibit primarily a diffusion controlled release mechanism, while ER alprazolam 3 mg deviates from pure diffusional release. The limitations of the model are discussed and point to the need for continued study of the swelling kinetics of matrix ER systems.
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Gao P, Watkins DC, Malbon CC. Constitutively active mutant GS alpha (G225T) and null-mutant G alpha i-2 (G203T) induce primitive endoderm from stem cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1995; 268:C1460-6. [PMID: 7611366 DOI: 10.1152/ajpcell.1995.268.6.c1460] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In F9 teratocarcinoma stem cells, retinoic acid induces a primitive endoderm-like phenotype and a sharp decline in G alpha i-2, a response mimicked by expression of RNA antisense to G alpha i-2 in the absence of this morphogen (D. C. Watkins, G. L. Johnson, and C. C. Malbon. Science Wash. DC 258: 1373-1375, 1992). The role of the GS alpha/G alpha i-2 axis in cellular differentiation was explored. In the absence of retinoic acid, F9 stem cells stably expressing a constitutively active mutant of GS alpha (G225T) progressed to the primitive endoderm phenotype, as judged by morphological and differentiation markers, such as tissue plasminogen activator. Although elevated in cells expressing G225T GS alpha, adenosine 3',5'-cyclic monophosphate does not mimic retinoic acid action and alone fails to induce stem cells to primitive endoderm. In the absence of retinoic acid, expression of a null mutant of G alpha i-2 (G203T) also induced stem cells to primitive endoderm. These observations establish G proteins in the GS alpha/G alpha i-2 axis as a control point for regulating progression to primitive endoderm independent of adenylate cyclase, in the present study's model of early mouse development.
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Pegram RA, Diliberto JJ, Moore TC, Gao P, Birnbaum LS. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) distribution and cytochrome P4501A induction in young adult and senescent male mice. Toxicol Lett 1995; 76:119-26. [PMID: 7725343 DOI: 10.1016/0378-4274(94)03212-p] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
While the developmental toxicology of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and its congeners has received considerable attention, the impact of advanced age on the biochemical effects and the pharmacokinetics of dioxins remains largely undetermined. In the present investigation, TCDD tissue distribution and cytochrome P4501A (CYP1A) induction were characterized in male C57BL/6N mice aged 10 weeks and 28 months at 7 days after administration of single oral [3H]TCDD doses ranging from 0.015 to 15 microgram/kg body wt. Determinations of hepatic marker enzyme activities for CYP1A1 (ethoxyresorufin O-deethylation, EROD) and 1A2 (acetanilide-4-hydroxylation, ACOH) indicated that the dose response curves for EROD induction by TCDD were nearly identical for the 2 age groups, but the ACOH induction response was greater in old mice. After receiving the 15 micrograms/kg dose, an increase (approximately 35%) in relative liver weight was observed 7 days after dosing in the 10-week mice, but not in the aged mice, and the hepatic concentration of TCDD was approximately 25% greater in young than old mice. No age difference was found in hepatic nuclear concentrations of TCDD. A dose-dependent increase in liver:fat tissue concentration ratios was noted at both ages, and adipose tissue and blood concentrations of TCDD did not vary significantly with age. In old mice however, TCDD concentrations in skin, kidney and muscle were all approximately twice those of young mice at the 15 micrograms/kg dose. These results suggest that advanced age may have differential effects on Ah receptor-mediated enzyme induction, while increased TCDD concentrations in certain tissues may have toxicological implications for older animals.
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Nishimura H, Sugawara K, Gao P, Muraki Y, Hongo S, Kitame F, Nakamura K. Identification of influenza C virus phosphoproteins. Microbiol Immunol 1995; 39:737-40. [PMID: 8577290 DOI: 10.1111/j.1348-0421.1995.tb03251.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The HMV-II cells infected with influenza C virus were labeled with inorganic [32P]phosphate to identify phosphorylated proteins. Analysis by radioimmunoprecipitation with antiviral serum or monoclonal antibodies revealed that three major structural proteins of the virus, hemagglutinin-esterase (HE), nucleoprotein (NP), and matrix protein (M1) are all phosphorylated in both infected cells and virions. It was also observed that, in the presence of trypsin (10 micrograms/ml), the unphosphorylated form of the HE glycoprotein was cleaved efficiently whereas the phosphorylated form was not, raising the possibility that phosphorylation of HE may influence its susceptibility to degradation by proteolytic enzymes.
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Mischke U, Fraudendienst-Egger G, Matthis P, Gao P, Trefz FK. KBS-DIAMET: database and expert system for diagnosis and treatment of patients with inborn errors of metabolism. J Inherit Metab Dis 1995; 18:224-6. [PMID: 7564253 DOI: 10.1007/bf00711773] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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283
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Saito S, Rojekittikhun W, Gao P, Yamashita T, Watanabe T, Sakato N, Sendo F. Characterization of the recognition specificity of autoreactive, polyspecific monoclonal antibodies obtained from spleen cells of parasite-infected BALB/c mice. Parasite Immunol 1994; 16:609-17. [PMID: 7708427 DOI: 10.1111/j.1365-3024.1994.tb00317.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We examined the specificity of four monoclonal antibodies (MoAbs) obtained from Schistosoma japonicum (1D, GAO3), Trypanosoma cruzi (TSLO), and Trichinella spiralis (TSY2) infected BALB/c mice. All four MoAbs reacted not only with autologous parasite antigens but also with various heterologous parasite antigens and normal tissues. The antigen recognition pattern seen on Western blots was almost identical in 1D and GAO3, and in TSLO and TSY2. Furthermore, certain bands were identical among all four MoAbs. The mechanisms responsible for these phenomena are discussed.
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Gao P, Su Y, Gao Y. [A murine model of mammary adenocarcinoma (VI TA2MA-891) with high rate of spontaneous metastases in the lungs]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1994; 16:147-52. [PMID: 7527302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The primary donor tumor was a spontaneous mammary tumor which arose in a 348-day-old female TA2 mouse. The pedigree number of that mouse was 0901-1423. The mouse was sacrificed for serial s.c. transplantation with 3 isogeneic hosts on January 19, 1989 and a total of 27 generations succeeded by the end of April, 1992. The primary donor tumor was diagnosed pathologically as a type B mouse mammary adenocarcinoma (Dunn 1959). The incidence of this serial s.c. transplantation tumor is 100% after inoculation. The latency period is 4-7 days and the lifetime of tumorbearing mice is about 47 days. The spontaneous metastatic rates in the lungs was 100% after the 11th generations. The earliest metastasis seen in the lung under light microscopy was on the 10th day after inoculation, and the earliest seen by gross examination was on about the 35th day. The transplanted tumor grew slowly from the 4th day to the 21st day after inoculation and then grew rather fast from the 22nd to the 47th day. The average size of the transplanted tumor obtained from 10 recipient mice on the 47th day after inoculation was 4.93cm3. Seven anticancer drugs were administered respectively for a sensitivity test. The taking rates of the transplanted tumor using 4 of the 7 drugs were as follows: 5-fluorouracil 29.27% (P < 0.05); thio-tepa 44.80% (P < 0.01); cyclophosphamide 95.31% (P < 0.01); and bleomycin 96.27% (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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Gao P. [Two high spontaneous lung and lymph node metastasis models derived from 615 mouse pulmonary adenocarcinoma (I615PAC-8811)]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1993; 15:266-73. [PMID: 8168206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The primary donor tumor of these 2 models was a spontaneous pulmonary adenocarcinoma which was originally developed in a 23-month-old male 615 mouse in our laboratory. That mouse was sacrificed for s.c. transplantation to 2 isogeneic hosts on November 12, 1988. A total of 50 generations for diffuse type and 30 generations for nodule type have since succeeded. Nodule type: The incidence of serial s.c. transplantation of this type of tumor was 100% with a latency period of 4-7d, and the lifetime of the tumor-bearing mice was about 44d. Spontaneous metastatic rate in the lungs was 100% from the 1st to the 20th generations. Diffuse type: The incidence of the s.c. transplantation tumor was 100%. The latency period was 3-6 d and the lifetime of the tumor-bearing mice was about 22 d. The spontaneous metastatic rate in the lungs and lymph nodes (after the 7th generation) was 100% from the 1st through the 35th generations. The origin of these 2 types was the same and their morphological features were similar. But several of their biological characteristics (including drug sensitivity and s.c. transplantation tumor growth speed) were different.
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Chou MW, Lu MH, Pegram RA, Gao P, Cao S, Kong J, Hart RW. Effect of caloric restriction on aflatoxin B1-induced DNA synthesis, AFB1-DNA binding and cell proliferation in Fischer 344 rats. Mech Ageing Dev 1993; 70:23-33. [PMID: 8231286 DOI: 10.1016/0047-6374(93)90056-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Young adult male Fischer rats maintained on a reduced calorie diet (60% of ad libitum food consumption) for 6 weeks showed a decrease in the binding of aflatoxin B1 (AFB1) to hepatic or renal nuclear DNA and a reduction of AFB1-induced hepatocellular damage. Repeated dosing of rats with AFB1 resulted in the inhibition of hepatic and renal DNA synthesis measured by [3H]thymidine incorporation. However, the rate of DNA synthesis was greater in ad libitum (AL) rats than in calorically restricted (CR) animals. Three days after AFB1 dosing, the rate of DNA synthesis had recovered to the control level. Cell cycle analyses measured by a flow cytometric method on kidney cells of both AL and CR rats showed that there were no significant changes in cell populations in the S phase between these two groups of rats. AFB1 inhibited the cell proliferation on an average of 33%. The restoration of the cell proliferation in kidney cells was found on the third day after AFB1 dosing. The rate of the regenerative cell proliferation was found to be slightly greater in AL rats than in CR animals. The AFB1-induced regenerative DNA synthesis in both liver and kidney was retarded by CR.
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Zhou WQ, Gao P. [Effect of youjiangzhi capsule on senile hyperlipidemia]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1993; 13:428-9, 390. [PMID: 8251730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
61 aged with hyperlipidemia were randomly divided into treatment and control group according to the ratio of 2:1, which were treated with Youjiangzhi capsule and Mai-an Powder respectively. After 8 weeks of administration, all of the four indexes of blood lipid (TC, TG, HDL-C, TC-HDL-C/HDL-C) were significantly improved in both groups, but the effective rate of TC-HDL-C/HDL-C was much better in treatment group than that in control. The result showed that there was a good effect of Youjiangzhi Capsule on the senile hyperlipidemia.
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Gao P. [The distribution of glycosaminoglycans in the temporomandibular ligament]. ZHONGHUA KOU QIANG YI XUE ZA ZHI = ZHONGHUA KOUQIANG YIXUE ZAZHI = CHINESE JOURNAL OF STOMATOLOGY 1992; 27:282-4, 318-9. [PMID: 1306441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The distribution of glycosaminoglycans (GAGs) in the adult dog's Temporomandibular ligament (TML) was studied by histochemical methods. Two staining methods were used, Alcian blue/PAS and Alcian blue with different concentration of MgCl2 (the Critical electrolyte concentration (CEC) method). It was found that GAGs were mainly localized in the TML, especially in the ligamental midsubstance and condylar attachment area, rather than in the capsule. Various GAGs distributed differently between the TML and capsule and they were also different among the different parts of the TML, although the majority of the CEC values was found corresponded to those of Chondroitin/Dematan Sulfate. It was suggested that the different topographical distribution of GAGs between the TML and capsule was probably related to their structure and function.
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Gao P, Chou MW. Effect of caloric restriction on hepatic nuclear DNA damage in male Fischer 344 rats treated with aflatoxin B1. Toxicol Lett 1992; 61:233-42. [PMID: 1641870 DOI: 10.1016/0378-4274(92)90150-i] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Caloric restriction is known to reduce chemically-induced tumor incidence in laboratory animals. The effect is believed to be mediated in part by modification of hepatic drug metabolism, including both phase I and phase II enzymes. Using aflatoxin B1 (AFB1) as a model carcinogen, we studied the effect of caloric restriction on the modification of rat liver nuclear DNA by AFB1 and DNA damage due to the formation of apurinic sites from the AFB1-DNA adduct removal process. Caloric restriction reduced the metabolic activation of AFB1 which resulted in a decrease of AFB1-DNA binding by more than 50%. The results of the study of the effect of caloric restriction on the AFB1-induced DNA strand breakage assayed by the alkaline unwinding technique showed that caloric restriction protected the formation of apurinic sites from the AFB1-DNA adducts and reduced the double strand DNA breakages by 1.3-2.5-fold. Thus, the lower initial AFB1-DNA binding and less DNA damage, presumably by the less apurinic sites formed during the depurination process of AFB1-DNA adducts, contributed to the protective effect of caloric restriction.
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Gao P, Xu Y. [Biochemical studies of the temporomandibular ligament in dogs]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1992; 23:37-40. [PMID: 1398621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The purpose of this investigation was to determine the biochemical composition of the normal adult dog's temporomandibular ligament (TML) along its ligament (TML) along its length. Water content and hexosamine concentration as an index of glycosaminoglycan content and collagen concentration were quantified; and the results compared statistically with anatomically identified TML segments. The TML contained lower water content and higher collagen, hexosamine concentration than capsule (P less than 0.05). All the contents of these components in different locations along the ligament were not significantly different, with the exception that on the insertion site of the temporal eminence the concentration of the hexosamine was less than that in other areas (P less than 0.05). This study provided useful data for the analysis of TML functions and its mechanical properties.
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Gao P, Mackley M. Surface treatment of ultra high molecular weight polyethylene to enhance adhesion and conductivity properties. POLYMER 1992. [DOI: 10.1016/0032-3861(92)90608-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Yu S, Chen Z, Chen Y, Jiang C, Guo T, Jiang B, Gao P, Kong X. The therapeutic and biological effects of total lymph node irradiation and autologous bone marrow infusion on malignant lymphoma patients. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 1991; 6:197-202. [PMID: 1813057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Forty patients with malignant lymphoma were treated by 60Co total lymphoid irradiation (TLI): 21 cases received 6 Gy and 19 received 8 Gy. Ten also received autologous bone marrow infusion (ABMI). Acute radiation damage with digestive tract reaction and hemopoietic and immunological depression was observed. Bone marrow was depressed. WBC and platelets decreased rapidly. Lymphocytes showed quantitative and qualitative changes even at the early stage. All these symptoms subsided within 40 days. TLI accompanied by irradiation of the tumor site could result in effective control. The 1-, 3-, and 5-year survival rates of malignant lymphoma patients were 30/40 (75%), 14/24 (58%) and 4/12 (33%), respectively, while in those with Hodgkin's disease alone, the 1- and 3-year survival rates were 10/13 (76%) and 5/7 (71.4%), respectively. ABMI hastened hemopoietic reconstitution, which recovered relatively quickly after TLI.
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Rauch U, Gao P, Janetzko A, Flaccus A, Hilgenberg L, Tekotte H, Margolis RK, Margolis RU. Isolation and characterization of developmentally regulated chondroitin sulfate and chondroitin/keratan sulfate proteoglycans of brain identified with monoclonal antibodies. J Biol Chem 1991; 266:14785-801. [PMID: 1907283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A panel of monoclonal antibodies prepared to the chondroitin sulfate proteoglycans of rat brain was used for their immunocytochemical localization and isolation of individual proteoglycan species by immunoaffinity chromatography. One of these proteoglycans (designated 1D1) consists of a major component with an average molecular size of 300 kDa in 7-day brain, containing a 245-kDa core glycoprotein and an average of three 22-kDa chondroitin sulfate chains. A 1D1 proteoglycan of approximately 180 kDa with a 150-kDa core glycoprotein is also present at 7 days, and by 2-3 weeks postnatal this becomes the major species, containing a single 32-kDa chondroitin 4-sulfate chain. The concentration of 1D1 decreases during development, from 20% of the total chondroitin sulfate proteoglycan protein (0.1 mg/g brain) at 7 days postnatal to 6% in adult brain. A 45-kDa protein which is recognized by the 8A4 monoclonal antibody to rat chondrosarcoma link protein copurifies with the 1D1 proteoglycan, which aggregates to a significant extent with hyaluronic acid. A chondroitin/keratan sulfate proteoglycan (designated 3H1) with a size of approximately 500 kDa was isolated from rat brain using monoclonal antibodies to the keratan sulfate chains. The core glycoprotein obtained after treatment of the 3H1 proteoglycan with chondroitinase ABC and endo-beta-galactosidase decreases in size from approximately 360 kDa at 7 days to approximately 280 kDa in adult brain. In 7-day brain, the proteoglycan contains three to five 25-kDa chondroitin 4-sulfate chains and three to six 8.4-kDa keratan sulfate chains, whereas the adult brain proteoglycan contains two to four chondroitin 4-sulfate chains and eight to nine keratan sulfate chains, with an average size of 10 kDa. The concentration of 3H1 increases during development from 3% of the total soluble proteoglycan protein at 7 days to 11% in adult brain, and there is a developmental decrease in the branching and/or sulfation of the keratan sulfate chains. A third monoclonal antibody (3F8) was used to isolate a approximately 500-kDa chondroitin sulfate proteoglycan comprising a 400-kDa core glycoprotein and an average of four 28-kDa chondroitin sulfate chains. In the 1D1 and 3F8 proteoglycans of 7-day brain, 20 and 33%, respectively, of the chondroitin sulfate is 6-sulfated, whereas chondroitin 4-sulfate accounts for greater than 96% of the glycosaminoglycan chains in the adult brain proteoglycans.(ABSTRACT TRUNCATED AT 400 WORDS)
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295
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Gao P, Mackley M. Effect of presolvent loading on the ultimate drawability of ultra-high molecular weight polyethylene. POLYMER 1991. [DOI: 10.1016/0032-3861(91)90133-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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296
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Liu YH, Wang XG, Gao P, Qian MX. Experimental and clinical trial of albendazole in the treatment of Clonorchiasis sinensis. Chin Med J (Engl) 1991; 104:27-31. [PMID: 1879192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Rats and dogs experimentally infected with Clonorchias sinensis metacercariae were treated orally with albendazole. Necropsy done seven days after treatment revealed that the worm reduction rates were 83.6% and 96.8% respectively. Clinically, 131 patients were treated with 3 different dosage regimens in 3 study groups. In patients receiving 5 mg/kg b.i.d. for 7 consecutive days, the stool egg negative conversion rates 1-month and 6-month post treatment were 90% and 92.6%, while in patients receiving 10 mg/kg b.i.d. for 7 consecutive days the rate were both 100%. In another group of patients receiving 10 mg/kg b.i.d. for 3 consecutive days, the 1-month and 3-month average stool egg conversion rates after treatment were only 40.0% and 28.3% respectively. The side reactions of albendazole were mild and transient. The liver and renal function tests, electrocardiography and blood and urine examinations showed no remarkable changes before and after treatment. The therapeutic effect of albendazole is comparable to praziquantel. It has the advantage of clearing various intestinal helminthic infections simultaneously, very low toxicity, excellent tolerance and relatively low cost, though its treatment course for clonorchiasis needs 7 days.
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297
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Yang T, Gao P. Stimulated four-photon mixing with crossed pump dividing in an optical fiber. OPTICS LETTERS 1990; 15:1002-1004. [PMID: 19770979 DOI: 10.1364/ol.15.001002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
An experimental study of stimulated four-photon mixing with crossed pump dividing in a birefringent optical fiber is described. The interactive four photons are all in the same mode but with different polarizations. The pump wave is distributed in two orthogonal linear polarizations, and the polarizations of Stokes and anti-Stokes waves are also orthogonal. It is shown that the Stokes shift of this stimulated four-photon mixing process is related not only to the material dispersion but also to the waveguide dispersion and is directly proportional to the birefringence.
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Gao P, Mackley M, Nicholson T. Development of anisotropy in ultra-high molecular weight polyethylene. POLYMER 1990. [DOI: 10.1016/0032-3861(90)90112-c] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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300
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Qin J, Wang L, Yuan DP, Gao P, Zhang BZ. Chaos and bifurcations in periodic windows observed in plasmas. PHYSICAL REVIEW LETTERS 1989; 63:163-166. [PMID: 10040796 DOI: 10.1103/physrevlett.63.163] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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