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Ichikawa J, Kuroki T, Dai J, Meltzer HY. Effect of antipsychotic drugs on extracellular serotonin levels in rat medial prefrontal cortex and nucleus accumbens. Eur J Pharmacol 1998; 351:163-71. [PMID: 9686999 DOI: 10.1016/s0014-2999(98)00308-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Amperozide, clozapine, olanzapine and risperidone are more potent serotonin (5-hydroxytryptamine, 5-HT)2A receptor antagonists than dopamine D2-like receptor antagonists. Haloperidol and S(-)-sulpiride are potent or selective dopamine D2-like receptor antagonists and lack 5-HT2A receptor antagonist properties. We studied the effect of these five proven antipsychotic drugs and one putative (amperozide) antipsychotic drug on extracellular 5-HT levels in the medial prefrontal cortex and the nucleus accumbens of awake, freely-moving rats, using in vivo microdialysis with dual probe implantation. Risperidone (1 mg/kg) and clozapine (20 mg/kg) significantly increased extracellular 5-HT levels in the medial prefrontal cortex and the nucleus accumbens, respectively. Amperozide (2 and 10 mg/kg) significantly increased extracellular 5-HT levels in both regions. Olanzapine (1 and 10 mg/kg), S(-)-sulpiride (10 and 25 mg/kg), haloperidol (0.1 and 1 mg/kg) and the selective 5-HT2A receptor antagonist MDL-100,907 (1 mg/kg) had no significant effect on extracellular 5-HT levels in either region. Thus, the ability to increase extracellular 5-HT levels in the medial prefrontal cortex and the nucleus accumbens by these antipsychotic drugs is not directly related to their affinity for 5-HT2A receptors since olanzapine and MDL-100,907 had no significant effect on extracellular 5-HT levels. A variety of mechanisms other than those involving 5-HT2A receptors, e.g., reuptake inhibition (amperozide) and blockade of alpha2-adrenoceptors (clozapine), may contribute to the ability to increase extracellular 5-HT levels in the brain. The increase in extracellular 5-HT levels in the medial prefrontal cortex or nucleus accumbens following amperozide, clozapine, or risperidone administration may not be related to the effect on psychotic symptoms but could be related to effects on other types of psychopathology such as depression, negative symptoms, or cognition.
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377
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Liu SY, Tappia PS, Dai J, Williams SA, Panagia V. Phospholipase A2-mediated activation of phospholipase D in rat heart sarcolemma. J Mol Cell Cardiol 1998; 30:1203-14. [PMID: 9689594 DOI: 10.1006/jmcc.1998.0685] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of phospholipase A2 (PLA2)-dependent release of unsaturated fatty acids (FA) on phospholipase D (PLD) function was examined in purified sarcolemmal (SL) membranes isolated from rat heart. PLD hydrolytic activity was determined by measuring either [14C] phosphatidic acid formation from exogenous [14C] phosphatidylcholine (PtdCho) or [3H] choline release from prelabelled SL Ptd[3H]choline. SL membranes with endogenous [3H] PtdCho that were prelabelled with [3H] myristic acid were used for testing PLD transphosphatidylation activity. Exogenous cis-unsaturated FA, arachidonate and oleate, significantly enhanced the [3H] choline formation at 50 and 100 microM, respectively; their effect was maximal at 250 microM and declined at higher concentrations. Use of melittin (which stimulates membrane-bound PLA2, thus releasing FA) or exogenous PLA2 reproduced the stimulatory effect of added arachidonate and oleate. Under melittin, PLA2-dependent FA release was strongly correlated (r = 0.99) to the PLD-dependent phosphatidic acid formation. Arachidonate- or melittin-enhanced PLD transphosphatidylation activity confirmed the augmented catalytic rate of PLD by these agents. Melittin-evoked PLD activation was completely blocked by 1 microM E-6-(bromomethylene) tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one, a selective inhibitor of Ca(2+)-independent v Ca(2-)-dependent PLA2, thus indicating that PLD stimulation under melittin occurred via PLA2. Activity measurement and Western blotting studies revealed the presence of a Ca(2+)-independent, high molecular weight (110 kDa) PLA2 in the SL membrane, and its immunoprecipitation by monoclonal antibodies significantly reduced the melittin-related PLD stimulation. These results suggest that Ca(2+)-independent PLA2 and subsequent endogenous mobilization of sn-2 unsaturated FA modulate PLD activity in heart SL membranes. This event may occur in physiological conditions via hormonal stimulation of membranal PLA2 as well as in heart diseases characterized by PLA2 pathological dysfunction.
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378
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Zhao E, Dai J, Chen D, Lin H. [Clinical diagnostic standard of mediopatellar plica syndrome]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 1998; 36:355-7. [PMID: 11825410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To increase the level of clinical diagnosis of mediopatellar plica syndrome. METHOD We reviewed the preoperative clinical symptoms of 67 knee joints that were proved to have pathologic mediopatellar plica by arthroscopy. RESULT Mediopatellar plica syndrome had the following clinical symptoms: painful knee and mediopatellar tenderness in all patients; tender bands in 56.7% patients; positive test of flexion or extension with internal femoral condyle pressed in 62.7% patients; positive Mcmarry's sign in 31.3% patients. CONCLUSION The clinical diagnostic standard of mediopatellar plica syndrome is that the first above-mentioned clinical symptom plus one of other three symptoms could suggest the diagnosis, while the first clinical symptom plus two or three of other three symptoms could define the diagnosis.
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379
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Dai J, Liu N, Feng L. Effect of the RF cavity temperature on low-energy injection at HLS. JOURNAL OF SYNCHROTRON RADIATION 1998; 5:372-373. [PMID: 15263514 DOI: 10.1107/s0909049597015082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/1997] [Accepted: 10/31/1997] [Indexed: 05/24/2023]
Abstract
The resonant frequency shift caused by the temperature of the RF cavity at the Hefei Light Source has been measured and the results analysed. The effect of this frequency shift on low-energy injection with a low cavity voltage is discussed, and a new injection mode is proposed.
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380
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Gerald N, Dai J, Ting-Beall HP, De Lozanne A. A role for Dictyostelium racE in cortical tension and cleavage furrow progression. J Cell Biol 1998; 141:483-92. [PMID: 9548725 PMCID: PMC2148450 DOI: 10.1083/jcb.141.2.483] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/1997] [Revised: 02/18/1998] [Indexed: 02/07/2023] Open
Abstract
The small GTPase racE is essential for cytokinesis in Dictyostelium. We found that this requirement is restricted to cells grown in suspension. When attached to a substrate, racE null cells form an actomyosin contractile ring and complete cytokinesis normally. Nonetheless, racE null cells fail completely in cytokinesis when in suspension. To understand this conditional requirement for racE, we developed a method to observe cytokinesis in suspension. Using this approach, we found that racE null cells attempt cytokinesis in suspension by forming a contractile ring and cleavage furrow. However, the cells form multiple blebs and fail in cytokinesis by regression of the cleavage furrow. We believe this phenotype is caused by the extremely low level of cortical tension found in racE null cells compared to wild-type cells. The reduced cortical tension of racE null cells is not caused by a decrease in their content of F-actin. Instead, mitotic racE null cells contain abnormal F-actin aggregates. These results suggest that racE is essential for the organization of the cortical cytoskeleton to maintain proper cortical integrity. This function of racE is independent of attachment to a substrate, but can be bypassed by other signaling pathways induced by adhesion to a substrate.
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381
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Dai J, Li J, Liu Y. [Imaging findings of primary sarcoma in the kidney]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1998; 20:137-9. [PMID: 10920966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
OBJECTIVE To reveal the characteristic findings of primary sarcoma of the kidney. METHODS From December 1988 through February 1996, seven cases of renal sarcoma confirmed by histo-pathology were retrospectively reviewed, including 3 leiomyosarcoma and 1 for each of liposarcoma, fibrosarcoma, malignant fibrous histiocytoma and malignant Schwannoma. Image material: CT in 6 cases, ultrasonography in 6 cases and MRI in 1 case. RESULTS The tumor was located in renal parenchyma in 6 cases and in renal pelvis in 1 case. On the images, it was commonly a large mass with irregular margin, indefinite, circumscribed and heterogeneous in density with necrosis inside as observed on the CT scan and 2 cases with median to hyperattenuation on the enhanced CT scan; 4/6 cases gave median heterogeneous mixed echo and 2/6 cases appeared as even hypoechoic mass on the ultrasonogram. On MRI, the mass gave isosignal intensity on T1WI and increased signal intensity with moderate heterogeneity was seen on T2WI or became more enhanced and heterogeneous but no more than renal parenchyma on the enhanced T1WI of MRI. Big tumor thrombus in the inferior vena cava and renal vein was noted in the fibrosarcoma. CONCLUSIONS Primary renal sarcomas give imaging findings characteristic of malignant tumor but without histological specificity and can not be differentiated from renal cell carcinoma. The enhanced CT and MRI capable of providing useful information of the localization, changes in density/signal and extent of invasion of the tumor, are beneficial to the differential diagnosis and managements.
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382
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Dai J, Liang S. A clinical observation on coronary heart disease treated by otopuncture at heart otopoint. J TRADIT CHIN MED 1998; 18:43-6. [PMID: 10437262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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383
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384
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Tian X, Yuan L, Li Y, Huo X, Han X, Xu M, Lu M, Dai J, Dong L. Ultrastructural observation on spermatocytogenesis in Taeniid cestodes. ZHONGGUO JI SHENG CHONG XUE YU JI SHENG CHONG BING ZA ZHI = CHINESE JOURNAL OF PARASITOLOGY & PARASITIC DISEASES 1998; 16:209-12. [PMID: 12078244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
AIM To study the spermatocytogenesis of taeniid cestodes at the ultrastructural leaves. METHODS Transmission electron microscopy. RESULTS The ultrastructural observation on spermatocytogenesis in Taenia solium, T. saginata and T. pisiformis were made by TEM. Two types of spermatogonia; type A and B, as well as the supporting cells surrounding the peripheral of spermatogonia are recognized. The type A spermatogonia are stem cells and the type B are mother cells which produce 16 primary spermatocytes by mitosis for 4 times with the cells unseparated. The primary spermatocytes are characterized by the ribosome masses in the cytoplasm. 32 secondary spermatocytes arranged in roselike were produced by reductive division of primary spermatocytes. The secondary spermatocytes become the spermatid quickly by short time development. CONCLUSION The dividing mode of spermatogonia in Taeniid cestodes is mitosis with cells unseparated.
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385
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Peng Y, Chen R, Sun S, Dai J, Wang J. [Immunodiagnosis of cysticercosis by simplified western blotting using recombinant fusion protein as antigen]. ZHONGGUO JI SHENG CHONG XUE YU JI SHENG CHONG BING ZA ZHI = CHINESE JOURNAL OF PARASITOLOGY & PARASITIC DISEASES 1998; 16:360-3. [PMID: 12078274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
AIM To provide simple and useful method for the immunodiagnosis of cysticercosis. METHODS Fusion protein of beta-galactosidase-Cysticercus cellulosae cDNA was analysed with simplified Western blot. RESULTS The positive rate was 93.5% when detecting 124 cases of human cysticercosis sera with four clones (cC1, cC2, cP1 and cH1) and 100% when detecting 38 cases of porcine cysticercosis sera with three clones (cC1, cC2 and cP1), being higher than those using monoclone fusion protein alone. Moreover, the fusion proteins did not react with other parasitosis sera. CONCLUSION Simplified Western blot analysis using recombinant fusion protein as antigen was highly sensitive and specific and easy to be operated.
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386
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Ren L, Shi D, Dai J, Ru B. Expression of the mouse metallothionein-I gene conferring cadmium resistance in a transgenic cyanobacterium. FEMS Microbiol Lett 1998; 158:127-32. [PMID: 9453164 DOI: 10.1111/j.1574-6968.1998.tb12811.x] [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: 02/06/2023] Open
Abstract
This paper reports the construction of a transgenic strain of cyanobacterium aimed at removing heavy metal pollution in waters. The mouse metallothionein-I (mMT-I) gene was inserted in the vector pRL-439 downstream of the strong psbA promoter. The resulting plasmid pRL-MT was ligated at the EcoRI site of the shuttle vector pKT-210 to generate the shuttle expression vector pKT-MT. This recombinant plasmid was introduced into Anabaena sp. PCC 7120 by triparental conjugative transfer. After selection on streptomycin, a stable transgenic Anabaena strain was obtained. The presence of the mMT-I gene was confirmed by DNA/DNA hybridization and its expression was demonstrated by immunodetection with specific antibodies. A metal tolerance experiment showed that this transgenic Anabaena strain had acquired higher metal resistance.
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387
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Dai J, Sheetz MP. Cell membrane mechanics. Methods Cell Biol 1997; 55:157-71. [PMID: 9352516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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388
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Krull IS, Liu X, Dai J, Gendreau C, Li G. HPCE methods for the identification and quantitation of antibodies, their conjugates and complexes. J Pharm Biomed Anal 1997; 16:377-93. [PMID: 9589395 DOI: 10.1016/s0731-7085(97)00071-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We review here much of the existing literature that deals with analysis, resolution, characterization, and (at times) quantitation of antibodies in capillary electrophoresis modes. Each major mode of CE shown applicable to antibody analysis is described, along with the major applications of that mode for antibodies. Discussions are presented as to the mechanisms of antibody resolution in CE, interactions of various buffer components with the proteins leading to resolution, and methods of quantitation for antibodies. The literature is critically reviewed with regard to true application of CE for antibody analysis, limitations, information possible, information implied, and which samples have actually been assayed by CE modes. The literature is critically reviewed up to and including 1996, both for the scientific and commercial literature, especially vendor applications and real world applications possible.
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389
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Cui K, Ding X, Xiao G, Dai J. [Analysis of triacylglycerol composition of perilla oil by combination of non-aqueous reversed-phase high performance liquid chromatography with gas chromatography]. Se Pu 1997; 15:470-3. [PMID: 15739324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023] Open
Abstract
Perilla oil was verified to be a rich source of polyunsaturated fatty acid (PUFA). Its linolenic content is 64.82%, the highest in the plants. Its triacylglycerol (TAG) components were isolated and identified first time in this paper by a combination of non-aqueous reversed-phase high performance liquid chromatography (RP-HPLC) with gas chromatography (GC). The TAG of perilla oil were isolated by HPLC with a Zorbax ODS column (5 microm, 4.6 mm i.d. x 250 mm; Dupont, Inc) and differential refractometer. The eluent was acetone/acetonitrile (80:20, V/V) with flow rate of 1.0 mL/min. The TAG component acyl groups were converted to fatty acid methyl esters (FAME). The acyl constituents for each TAG were determined by GC analysis. Gas chromatography of FAMEs was performed with a AC20 Carbowax 20M column (30 m x 0.32 mm i.d.). Detector and injection port temperatures were 260 degrees C. Column temperature was programmed from 120 degrees C, 1 min initially hold, then 8 degrees C/min to 220 degrees C and finally hold for 10 min. Nitrogen was the carrier gas. FAMEs peaks were identified by comparison of their retention times with those of standards. The retention times of the palmitic, stearic, oleic, linoleic, n-nonadecanoic acid (internal standard) and linolenic FAMEs were 10.7, 13.0, 13.3, 13.8, 14.2 and 14.7 min respectively. Five main components were determined. They were LnLnLn (34.10%), LnLnL (13.22%), LnLL (6.22%), LnLnO (11.38%) and LnLnP (9.17%). The TAG contents were corrected from their fatty acids content. The combination of non-aqueous RP-HPLC with GC is a simple and rapid method for the analysis of oil TAG structure and is also very helpful for the identification of oil quality.
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390
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Liu L, Dai J, Fandrich RR, Kardami E. Cell-cycle dependent anti-FGF-2 staining of chicken cardiac myocytes: movement from chromosomal to cleavage furrow- and midbody-associated sites. Mol Cell Biochem 1997; 176:153-61. [PMID: 9406157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Fibroblast growth factor-2 (FGF-2) promotes cardiac myocyte proliferation and has been detected in extracellular as well as cytoplasmic and nuclear compartments. As a first step in examining the participation of intracellular FGF-2 in cardiac myocyte cell cycle we have investigated its localization in proliferative chicken cells during interphase and the various stages of mitosis in culture. We have used a previously characterized and affinity-purified anti-FGF-2 antibody preparation which recognizes the 19-22 kDa variants of chick FGF-2. By immunofluorescence, bright, punctate anti-FGF-2 labelling was observed in 26% of interphase nuclei from myocytes derived from 5 day embryonic heart ventricles; these nuclei were positive for anti-bromodeoxyuridine staining indicating that they are at the S- or G2 phase of the cell cycle. In prophase and metaphase, bright anti-FGF-2 staining was detected in apparent association with chromosomes. During anaphase, however, anti-FGF-2 staining dissociated from chromosomal locations distinctly remaining in strand-like structures in the area of ensuing cleavage furrow formation. In late telophase and cytokinesis, strong staining persisted in the area of the midbody and reappeared in a small fraction of newly formed daughter nuclei. Absorption of the antibody preparation with immobilized FGF-2 eliminated all staining. This dynamic pattern of anti-FGF-2 staining suggests that chick FGF-2 or immunologically related protein(s) not only increase in DNA-synthesizing nuclei but they may play a role in subsequent stages of mitosis and cytokinesis.
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391
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Ku DD, Dai J. Expression of thrombin receptors in human atherosclerotic coronary arteries leads to an exaggerated vasoconstrictory response in vitro. J Cardiovasc Pharmacol 1997; 30:649-57. [PMID: 9388048 DOI: 10.1097/00005344-199711000-00016] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Alpha-thrombin can alter vascular tone by proteolytic cleavage of its cell-surface receptor, which exposes a tethered peptide sequence, Ser-Phe-Leu-Leu-Arg-Asn (SFLLRN) that activates the receptor. We investigated the effects of increasing severity of coronary atherosclerosis on SFLLRN-induced responses on 165 human coronary artery rings isolated fresh from 15 patients who underwent cardiac transplantation. In 40 coronary rings with minimal intimal proliferation, addition of 0.001-5 microM SFLLRN resulted in a dose- and endothelium-dependent relaxation reaching a maximum of -87.0 +/- 2.3% (mean +/- SEM) and median inhibitory concentration (IC50) of 0.1 microM. Increasing severity of atherosclerotic lesion, as determined by morphometric quantification of intimal thickening under light microscopy, resulted in graded decreases in both sensitivity and magnitude of the observed relaxation. The maximal relaxations in coronary arteries with mild and moderate intimal proliferation were -76.7 +/- 3.5% (mean +/- SEM of 41 rings) and -63.6 +/- 6.4% (mean +/- SEM of 22 rings), respectively. In the 21 coronary rings with severe intimal proliferation, no significant SFLLRN-induced relaxation was noted. Mechanical disruption of intimal endothelium abolished the SFLLRN-induced relaxation observed in the minimal to mild intimally thickened arteries, whereas in arteries with moderate and severe intimal thickening, a significant SFLLRN-induced contraction (19 +/- 10% and 43 +/- 7%, respectively) was observed. Similar endothelium-dependent relaxations in minimal atherosclerotic and endothelium-independent contraction in severe atherosclerotic coronary arteries were also observed with alpha-thrombin. These findings confirm a recent in situ hybridization and immunohistochemistry study reporting localization of cloned thrombin receptors only in endothelium of "normal appearing" human abdominal aortae and induced expression of thrombin receptors in intimal/medial regions of the atherosclerotic vessels and further demonstrate that similar expression of thrombin receptors in human atherosclerotic coronary arteries leads to an unmasking of a marked vasoconstrictory response.
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392
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Xue YC, Chen WJ, Dai J, Qi CQ, Zhen YS. [Antitumor activity of the clavam peptide antibiotic G0069A]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1997; 32:647-51. [PMID: 11596287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Antibiotic G0069A, produced by a Streptomyces strain isolated from a soil sample collected in Yunnan Province, China, has been verified as a clavam peptide. Determined by MTT assay, G0069A showed highly potent cytotoxicity to cancer cells with multidrug resistance. The IC50 values of G0069A to KB and KB/VCR cells were 0.60 and 0.46 mumol.L-1, and to MCF-7 and MCF-7/ADM cells were 1.4 and 1.2 mumol.L-1, respectively. G0069A displayed equally potent cytotoxicity to the parent cell lines and their resistant sublines. When administered by i.v. or i.p. route at tolerable doses, G0069A exhibited markedly inhibitory effect on the growth of sarcoma 180 and hepatoma 22 in mice. At dose level of 3 mg.kg-1, i.v., x3, sarcoma 180 and hepatoma 22 were suppressed by 87%(P < 0.01) and 72%(P < 0.01), respectively. The results indicate that G0069A is a beta-lactam antibiotic showing antitumor activity.
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393
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Fallon MB, Abrams GA, Luo B, Hou Z, Dai J, Ku DD. The role of endothelial nitric oxide synthase in the pathogenesis of a rat model of hepatopulmonary syndrome. Gastroenterology 1997; 113:606-14. [PMID: 9247483 DOI: 10.1053/gast.1997.v113.pm9247483] [Citation(s) in RCA: 150] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND & AIMS The hepatopulmonary syndrome occurs when intrapulmonary vasodilatation causes impaired arterial gas exchange in liver disease. The pathogenesis is poorly understood, although nitric oxide may be involved. Common bile duct ligation in the rat is a model of the hepatopulmonary syndrome, but no studies have evaluated NO in pulmonary vasodilatation in this model. The aim of this study was to determine whether NO contributes to intrapulmonary vasodilatation after bile duct ligation. METHODS Endothelial and inducible NO synthase (NOS) levels and localization and NO activity in pulmonary artery rings were assessed after bile duct ligation. RESULTS Pulmonary endothelial NOS levels increased and alveolar vascular staining was enhanced after bile duct ligation. No change in pulmonary inducible NOS levels or localization was detected. Increased endothelial NOS levels correlated with alterations in gas exchange and were accompanied by enhanced NO activity and a blunted response to phenylephrine, reversible by NOS inhibition, in pulmonary artery rings. Portal-vein-ligated animals, which do not develop intrapulmonary vasodilatation, had no changes in pulmonary NOS production or in NO activity in pulmonary artery rings. CONCLUSIONS NO, derived from pulmonary vascular endothelial NOS, contributes to intrapulmonary vasodilation in animal hepatopulmonary syndrome.
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394
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Dai J, Harrington JA. High-peak-power, pulsed CO(2) laser light delivery by hollow glass waveguides. APPLIED OPTICS 1997; 36:5072-5077. [PMID: 18259317 DOI: 10.1364/ao.36.005072] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Flexible hollow glass waveguides with internal metallic and dielectric coatings have been used to deliver high-peak-power transversely excited atmosphere CO(2) laser energy. The straight guide loss is as low as 0.17 dB/m for 1000-mum-bore guides and 0.46 dB/m for 530-mum-bore guides propagating the HE(11) mode. The loss increases to 0.93 and 1.36 dB/m, respectively, when guides are bent to a radius of 0.25 m. The hollow glass waveguides have been used to deliver pulsed CO(2) laser energy successfully with a peak power of 0.7 MW and an energy of 350 mJ per pulse with a gas purge through the hollow core. The delivered average power is as high as 27 W. It is concluded that these waveguides are promising candidates for pulsed CO(2) laser delivery in medical and surgical applications.
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395
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Dai J, Swaab DF, Buijs RM. Distribution of vasopressin and vasoactive intestinal polypeptide (VIP) fibers in the human hypothalamus with special emphasis on suprachiasmatic nucleus efferent projections. J Comp Neurol 1997; 383:397-414. [PMID: 9208989 DOI: 10.1002/(sici)1096-9861(19970714)383:4<397::aid-cne1>3.0.co;2-y] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The human suprachiasmatic nucleus (SCN) is located in the basal part of the anterior hypothalamus and is considered as the biological clock that generates circadian rhythms and synchronizes the daily activity pattern with the environmental light-dark cycle. However, the mechanisms and pathways by which the SCN transmits its information to the other brain areas are unknown. Therefore, in the present study, we investigated the efferent projections of the SCN by the immunocytochemical staining of two major peptidergic SCN neurotransmitters: vasopressin (VP) and vasoactive intestinal polypeptide (VIP). It confirmed that these peptides are present in different subdivisions of the SCN. The results of this investigation show that VP and VIP fibers arising from the SCN were detected to branch extensively and hence seem to innervate the SCN itself and the central and medial part of the anteroventral hypothalamic area (AVH), the area below the paraventricular nucleus (sub-PVN), the ventral part of the paraventricular nucleus (PVN), and the dorsomedial nucleus of the hypothalamus (DMH). There appeared to be substantial congruity between the presumptive human SCN projections and those as observed by tracing in rat or hamster. Regarding the anatomical organization of the human SCN projections, the main projection areas appeared to be the AVH, the sub-PVN, the ventral part of the PVN, and the DMH. The observation that VIP and in particular VP fibers pass between the SCN and the PVN suggests that the human SCN and the PVN may have a direct anatomical connection. In addition, VP and VIP fibers were detected in several other hypothalamic areas that are not known to have clear direct connections to the SCN. The possible origin of these VP and VIP fibers is discussed.
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396
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Dai J, Ting-Beall HP, Sheetz MP. The secretion-coupled endocytosis correlates with membrane tension changes in RBL 2H3 cells. J Gen Physiol 1997; 110:1-10. [PMID: 9234166 PMCID: PMC2229359 DOI: 10.1085/jgp.110.1.1] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Stimulated secretion in endocrine cells and neuronal synapses causes a rise in endocytosis rates to recover the added membrane. The endocytic process involves the mechanical deformation of the membrane to produce an invagination. Studies of osmotic swelling effects on endocytosis indicate that the increased surface tension is tightly correlated to a significant decrease of endocytosis. When rat basophilic leukemia (RBL) cells are stimulated to secrete, there is a dramatic drop in the membrane tension and only small changes in membrane bending stiffness. Neither the shape change that normally accompanies secretion nor the binding of ligand without secretion causes a drop in tension. Further, tension decreases within 6 s, preceding shape change and measurable changes in endocytosis. After secretion stops, tension recovers. On the basis of these results we suggest that the physical parameter of membrane tension is a major regulator of endocytic rate in RBL cells. Low tensions would stimulate endocytosis and high tensions would stall the endocytic machinery.
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Chen J, Dai J, Grant RL, Doctor RB, Sheetz MP, Mandel LJ. Loss of cytoskeletal support is not sufficient for anoxic plasma membrane disruption in renal cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 272:C1319-28. [PMID: 9142858 DOI: 10.1152/ajpcell.1997.272.4.c1319] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The goal of this study was to determine whether anoxic membrane disruption is initiated by loss of cytoskeletal support in rabbit renal proximal tubules (PT). We specifically tested 1) whether cytoskeletal perturbation affects membrane integrity under normoxia, 2) whether cytoskeletal perturbation potentiates anoxic membrane damage, and 3) whether the membrane protection by glycine depends on cytoskeletal integrity. Cytoskeletal perturbation was achieved with 10 microM cytochalasin D (CD) because it selectively disturbs F-actin organization and has similar effects as anoxia on the cytoskeleton of PT. During normoxia, CD caused decreased basal F-actin content, microvillar breakdown, and membrane-cytoskeleton dissociation, as revealed by the use of laser tweezers. However, membrane integrity was not altered by CD, as monitored by lactate dehydrogenase release. CD pretreatment of PT did not potentiate anoxic membrane damage. Finally, plasma membrane protection by glycine during anoxia remained in CD-pretreated PT despite loss of cytoskeletal support. These results demonstrate that loss of cytoskeletal support is not sufficient for anoxic plasma membrane disruption.
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398
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Yu A, Barron MD, Romero RM, Christy M, Gold B, Dai J, Gray DM, Haworth IS, Mitas M. At physiological pH, d(CCG)15 forms a hairpin containing protonated cytosines and a distorted helix. Biochemistry 1997; 36:3687-99. [PMID: 9132022 DOI: 10.1021/bi9625410] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
To investigate potential structures of d(CGG/CCG)n that might relate to their biological function and association with triplet repeat expansion diseases (TREDs), the structure of a single-stranded (ss) oligonucleotide containing d(CCG)15 [ss(CCG)15] was examined by studies of the pH and temperature dependence of electrophoretic mobility, UV absorbance, circular dichroism, chemical modification, and P1 nuclease digestion. ss(CCG)15 had an unusually high pKa (7.7 +/- 0.2). At pH 8.5, ss(CCG)15 formed a relatively unstable (Tm = 30 degrees C in 1 mM Na+) hairpin containing CpG base-pair steps. At pH 7.5, the hairpin contained protonated cytosines but no detectable C x +C base pairs, increased thermal stability (Tm = 37 degrees C), increased stacking of the CpG base-pair steps, and a single cytosine that was flipped away from the central portion of the helix. Examination of ss(CCG)18 and ss(CCG)20, which were designed to adopt hairpins containing alternative GpC base-pair steps, revealed hairpins containing CpG base-pair steps, pKas of approximately 8.2 and approximately 8.4, respectively, and distorted helices. The results suggest that DNA sequences containing (CCG)(n > or = 15) adopt hairpin conformations that contain CpG rather than GpC base-pair steps; the mismatched cytosines are protonated at physiological pH but are not H-bonded. We propose that protonation arises from the stacking of two cytosines in the minor groove of a distorted helix.
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399
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Dai J, Jiang L, Zhang Y. [Imaging findings of malignant fibrous histiocytoma in the lung]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1997; 19:130-3. [PMID: 10743078] [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 show the characteristic findings of the image of primary malignant fibrous histiocytoma (PMFH) in the lung. METHODS Fifty-one cases of pulmonary PMFH were reviewed, 7 from our hospital and 44 from the literature including chest radiograms 51 cases; CT scans 9 cases and MRI 1 case. RESULTS Primary MFH comprises 0.01% of all pulmonany malignant tumors seen in the same period. The mean age was 55 years. The most common complaints were cough, hemoptysis and chest pain. In 40 cases who were followed, recurrence/metastasis developed in 42.9% with 80% appearing within one year. The sites of the lesion were: right lobe in 34 cases and left lobe in 17 cases. It was peripheral in 49 (96.1%) cases and central in 2 (3.9%). The finding of the image was a large solitary mass (> 5 cm, 68.6%) with regular or irregular margin. Most of the tumors were well circumscribed (56.9%) or lobulated (43.1%) showing homogeneous attenuation (64.7%). Cystic changes or cavitation was observed in a few cases. On CT, the lesion shows low attenuation and involves the adjacent structures. CONCLUSION PMFH gives images which are not pathognomonic. Yet, its regular, well defined border, less lobulated configuration could differentiate itself from the common malignant and benign lesionsin the lung. CT and MRI can provide useful information in demonstrating the nature and extent of invasion of the tumor.
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400
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Zhang J, Wang C, Dai J, Chen X, Ge K. Palm oil diet may benefit mildly hypercholesterolaemic Chinese adults. Asia Pac J Clin Nutr 1997; 6:22-25. [PMID: 24394648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The effects on serum lipids and platelet function of diets prepared with palm oil (PA) and peanut oil (PE) were studied in two groups of mild hypercholesterolaemic volunteers (serum TC between 5.5 - 7.0 mmol/L, aged 32-68). There were 15 men and 11 women in PE group and 16 men and 9 women in PA group. Dietary fat provided about 30% of total calories, and the test oil accounted for 60-65% of total dietary fat. During the 3 weeks of pretest period, diets were prepared with peanut oil, the local habitual cooking oil for all subjects. During the next 6 weeks the subjects in PA group consumed a diet prepared with palm oil while subjects in PE group continued to consume a diet prepared with peanut oil. Compared to the entry-level values, the concentrations of serum TC (total cholesterol), LDL-C (low density lipoprotein cholesterol), TC/HDL-C (high density lipoprotein cholesterol) ratio and plasma TXB2/6-keto-PGF1a ratio were significantly decreased in PA group (-6.5%, -9.0%, -11.5%, and -22.4%) while not appreciably altered in PE group by the end of the test. No significant change was observed on the whole blood platelet aggregation in both groups. In connection with the results from our previous study in normocholesterolaemic Chinese volunteers, palm oil, used as cooking oil in Chinese diet, will not lead to any adverse effect on blood lipids and thus will not increase CVD risks.
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