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Lozanoff S, Johnston J, Ma W, Jourdan-Le Saux C. Immunohistochemical localization of Pax2 and associated proteins in the developing kidney of mice with renal hypoplasia. J Histochem Cytochem 2001; 49:1081-97. [PMID: 11511678 DOI: 10.1177/002215540104900903] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Pax2 has been identified as a key regulatory protein associated with renal developmental malformations. The purpose of this study was to determine whether Pax2 protein expression, and that of other proteins important for normal renal development, is abnormally distributed in the prenatal kidney of the Brachyrrhine (Br) mouse that displays heritable renal hypoplasia. Embryonic 3H1 +/+ and Br/Br mice were collected between E11.0 and E18.0. Routine light microscopy and immunohistochemical analysis using antibodies to Pax2, E-cadherin, fibronectin, laminin, and Type IV collagen were applied to sequential tissue sections. E-cadherin stained consistently in the renal tubules of both normal and mutant animals. Whereas the initial expression of Pax2 corresponded between normal and mutant kidneys, it became progressively limited to the nephrogenic zone in +/+ animals, while distributing erratically in the Br/Br kidney. Fibronectin was not expressed in the normal nephrogenic zone but remained abundantly distributed throughout the Br/Br kidney. Luminin and Type IV collagen staining revealed a deficiency in renal vasculature formation in Br/Br kidneys. Results suggest that initial morphological differentiation occurs normally in the Br kidney but that subsequent nephric formation is associated with abnormal distribution of Pax2 and ECM proteins. (J Histochem Cytochem 49:1081-1097, 2001)
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Yang Z, Zhu T, Ma G, Yin H, Qian W, Zhang F, Cao K, Ma W. Apolipoprotein E polymorphism in the early onset of coronary heart disease. Chin Med J (Engl) 2001; 114:983-5. [PMID: 11780396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE To assess the relationship between apolipoprotein E (apoE) polymorphism and the early onset of coronary heart disease (CHD) and the effect of apoE on lipids and lipoproteins in healthy Chinese subjects. METHODS Sixty-eight patients with CHD younger than 55 years (CHD1), 136 patients with CHD older than 65 years (CHD2), and 136 healthy subjects were enrolled, and their plasma levels of triglyceride (TG), total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) were determined. The apoE genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism. RESULTS apoE 3/4 genotype and E4 allele frequency in the CHD1 group were higher than those in the CHD2 group and healthy subjects, while no differences were found between CHD2 and healthy subjects. Meanwhile, the plasma levels of TC and low density lipoprotein cholesterol (LDL-C) were higher in the CHD2 group than in both CHD1 group and healthy subjects. Each apoE isoprotein has variable TC and LDL-C levels that is E2 (E2/2 + E2/3) < E3(E3/3) < E4(E4/4 + E3/4). CONCLUSION apoE is one of the genetic factors that affect TC and LDL-C levels, and apoE 4 has a very close relation to CHD, suggesting that apoE 4 is an independent genetic factor of the early onset of CHD.
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278
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Shaffer KM, Lin HJ, Maric D, Pancrazio JJ, Stenger DA, Barker JL, Ma W. The use of GABA(A) receptors expressed in neural precursor cells for cell-based assays. Biosens Bioelectron 2001; 16:481-9. [PMID: 11544042 DOI: 10.1016/s0956-5663(01)00162-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
GABA(A) receptors are known targets for certain classes of environmental neurotoxins and pharmaceutical compounds. Since few neural cell lines express functional GABA(A) receptors, the capacity to rapidly screen for compounds that affect GABA(A) receptor function is presently limited. Previous work has demonstrated that rat neural precursor cells express functional GABA(A) receptors that can be monitored via Ca(2+) imaging. This study examined GABA(A) receptor subunit expression to determine whether GABA(A) receptor function and its interactions with neurotoxins is preserved after passaging. Neural precursor cells isolated from embryonic day 13 rat brain were expanded in serum-free medium containing basic fibroblast growth factor and passaged three times. Reverse transcription-polymerase chain reaction analysis demonstrated early expression of abundant mRNAs encoding various GABA(A) receptor subunits. Ca(2+) imaging showed that the highly proliferating precursor cells in passaged cultures maintained expression of functional GABA(A) receptors. In addition, we showed that trimethylolpropane phosphate, a neurotoxin generated during partial pyrolysis of a synthetic ester turbine engine lubricant, potently inhibited muscimol (GABA(A) receptor agonist) but not depolarization-induced cytosolic Ca(2+) increase. The findings of this study suggest that neural precursor cells may be well suited for the evaluation of certain environmental neurotoxins with convulsant activity. The potential use of neural precursor cells in high-throughput screens for compounds acting on GABA(A) receptors is discussed.
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Li L, Yang Q, Huang J, Xu X, Chen Y, Chen Y, Ma W, Chen Z, Fu S. Treatment of hepatic failure with artificial liver support system. Chin Med J (Engl) 2001; 114:941-5. [PMID: 11780387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE To assess the effectiveness of artificial liver support system (ALSS) treatment in patients with hepatic failure. METHODS 235 cases of hepatic failure were treated with ALSS in our hospital. All data were analyzed by SPSS. The effectiveness of ALSS treatment was compared according to different stages (i.e., early, middle and end stages). RESULTS 108 patients survived after therapy of ALSS. After each ALSS treatment, the liver function of these patients was greatly improved, the serum endotoxin and HBV-DNA concentrations were significantly decreased, and the serum concentration of aromatic amino acids (AAA) such as methionine decreased while the ratio of branched chain amino acids and aromatic amino acids (BCAA/AAA ratio) increased; patients treated with ALSS in the early or middle stages of disease had much higher survival rates than patients in the end stage of disease. CONCLUSION ALSS is a reliable therapy for advanced liver diseases and treatment at early or middle stages is appropriate.
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Ma W, Wang J, Liang C, Qi R, Yang M. [Anaerobic hydrolysis of terramycin crystallizing mother solution]. HUAN JING KE XUE= HUANJING KEXUE 2001; 22:41-4. [PMID: 11769226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The terramycin crystallizing mother solution contained high organics and high nitrogen. There were many kinds of bioinhibition in it but not enough electronic donor. Anaerobic hydrolysis of terramycin crystallizing mother solution was completed with up anarobic sludge bed in order to improve the biodegradability of wastewater and electronic donor in it. The variations of pH, COD, NH4+, and SO4(2-) were monitored. The COD removal was in a narrow range between 10% and 16.4% even when the HRT of the reactor was changed from 1.5 h to 6 h. pH increased because of formation of NH3 and reduction of SO4(2-). Most of SO4(2-) was reduced to S2- when the HRT was longer than 2 h. Batch experiments on hydrolyzed wastewater demonstrated that reaction rates of nitrification and denitrification increased by 90.9% and 45.2%, respectively.
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Ma W, Pancrazio JJ, Andreadis JD, Shaffer KM, Stenger DA, Li BS, Zhang L, Barker JL, Maric D. Ethanol blocks cytosolic Ca2+ responses triggered by activation of GABA(A) receptor/Cl- channels in cultured proliferating rat neuroepithelial cells. Neuroscience 2001; 104:913-22. [PMID: 11440820 DOI: 10.1016/s0306-4522(01)00084-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
GABA(A) receptor/Cl- channels and voltage-gated Ca2+ channels are believed to be important sites of ethanol action in the CNS. Acute exposure of ethanol potentiates GABA(A) receptor/Cl- channel activity and inhibits voltage-gated Ca2+ channels in a number of preparations, mostly post-mitotic neurons. The effects of ethanol on these channels in primary cultures of undifferentiated neural precursor cells remain unknown. To address this issue, we examined the effects of ethanol on GABA(A) agonist-activated elevation of cytosolic Ca2+ in an in vitro model of the cortical neuroepithelium derived from rat basic fibroblast growth factor-expanded neural precursor cells. We found a potent inhibition of GABA(A)-activated elevation of cytosolic Ca2+ by ethanol in actively proliferating cells. Since we had recently demonstrated that GABA(A) receptor activation depolarizes these cells and elevates their cytosolic Ca2+, we tested whether the effects of ethanol involved both GABA(A) receptors and voltage-gated Ca2+ channels. Both extracellular K+- and muscimol-induced cytosolic Ca2+ elevations were abolished by nitrendipine, indicating that both depolarizing stimuli triggered Ca2+ influx through L-type voltage-gated Ca2+ channels. Exposure of proliferating cells to different concentrations of ethanol revealed that the drug was more potent in blocking muscimol-induced compared to K+-evoked cytosolic Ca2+ elevations. These results raise the possibility that ethanol blocks GABAergic stimulation of cytosolic Ca2+ levels in proliferating precursors primarily by interacting with GABA(A) receptor/Cl- channels and secondarily with voltage-gated Ca2+ channels.
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282
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Zhang F, Huang Q, Ma W, Jiang S, Fan Y, Zhang H. Amplification and cloning of the full-length genome of Japanese encephalitis virus by a novel long RT-PCR protocol in a cosmid vector. J Virol Methods 2001; 96:171-82. [PMID: 11445147 DOI: 10.1016/s0166-0934(01)00331-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A novel and rapid full-length long RT-PCR technique was established to produce genome-length cDNA from Japanese encephalitis virus. In vitro positive strand RNA transcripts from the full-length RT-PCR amplicon including T7 promoter sequences at the 5' end were proved to be infectious upon transfection. The full-length amplicon without the T7 promoter was cloned into a cosmid vector under the SP6 promoter. This stable clone, designated as pJEV-1, was characterised further and used as a genetic resource for generation of infectious RNA transcripts, gene manipulation and expression. The 'run-off' transcript from pJEV-1 with vector sequences at the either end of the insert was not infectious, but transcripts of the full-length PCR amplicon from pJEV-1 produced infectious virus upon transfection. A transcript with an engineered Xho I site from two ligated PCR fragments amplified from pJEV-1 was also infectious. Furthermore, the coding region for premembrane and envelope proteins (preM-E) from pJEV-1 was subcloned and expressed in the Drosophila Expression System. The expressed protein showed correct molecular size and was immunoreactive with a Japanese encephalitis virus E protein-specific antibody. The derivation of genome-size cDNA from Japanese encephalitis virus and the stable clone will facilitate investigation of this virus and elucidation of its pathogenesis at the molecular level.
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MESH Headings
- Animals
- Cell Line
- Cloning, Molecular/methods
- Cosmids/genetics
- DNA, Complementary/genetics
- Encephalitis Virus, Japanese/genetics
- Encephalitis Virus, Japanese/pathogenicity
- Encephalitis, Japanese/virology
- Gene Amplification
- Genetic Vectors/genetics
- Genome, Viral
- Mice
- Mice, Inbred BALB C
- RNA, Viral/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Analysis, DNA
- Transcription, Genetic
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283
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Oste LA, Dolfing J, Ma W, Lexmond TM. Cadmium uptake by earthworms as related to the availability in the soil and the intestine. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2001; 20:1785-1791. [PMID: 11491563 DOI: 10.1897/1551-5028(2001)020<1785:cubear>2.0.co;2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The free metal concentration in the soil solution is often considered a key parameter for metal uptake by and toxicity to soft-bodied soil organisms. The equilibrium partitioning theory, which assumes a relationship between the contaminant concentration in pore water and the contaminant concentration in the body tissue, can be used to describe uptake by earthworms. This theory has proved useful for organic chemicals, but its applicability is less clear for metals. In this study, the Cd concentration in soil pore water (pw) was varied by increasing the soil pH by the addition of lime (Ca(OH)2) and by adding manganese oxide (MnO2), which has a high metal binding capacity. Both lime (0.135% w/w) and MnO2 (1% w/w) decreased [Cd2+]pw by a factor of 25, while Cdworm was reduced only by a factor of 1.3 in lime-treated soils and 2.5 in MnO2-treated soils. Cadmium uptake was weakly related to the free metal concentration (R2adj = 0.66). Adding pH as an explanatory variable increased R2adj to 0.89, indicating that Cd uptake from pore water is pH dependent, which might be attributed to competition of protons and Cd at the surface of the earthwororm body. However, previous earthworm experiments in reconstituted groundwater showed a conspicuously smaller pH dependency of Cd uptake. The differences in metal uptake between earthworms in lime- and MnO2-treated soils are therefore more likely to reflect the predominance of pH-independent intestinal uptake of Cd. Equilibrating the soil with a solution of 0.01 M CaCl2 and 0.1 M triethanolamine (buffered at pH 7.2), simulating the conditions prevailing in the worm intestine, yielded free Cd concentrations that were closely (R2adj = 0.83) and linearly related to the Cd concentration in the earthworm tissue.
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284
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Stenger DA, Gross GW, Keefer EW, Shaffer KM, Andreadis JD, Ma W, Pancrazio JJ. Detection of physiologically active compounds using cell-based biosensors. Trends Biotechnol 2001; 19:304-9. [PMID: 11451472 DOI: 10.1016/s0167-7799(01)01690-0] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cell-based biosensors are portable devices that contain living biological cells that monitor physiological changes induced by exposure to environmental perturbations such as toxicants, pathogens or other agents. Methods of detecting physiological changes include extracellular electrical recordings, optical measurements, and, in the future, functional genomics and proteomics. Several technical developments are occurring that will increase the feasibility of cell-based biosensors for field applications; these developments include stem cell and 3D culture technologies. Possible scenarios for the use of cell-based biosensors include broad-range detectors of unknown threat agents and functional assessment of identified agents.
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285
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Fujimori K, Ma W, Moriuchi-Kawakami T, Shibutani Y, Takenaka N, Bandow H, Maeda Y. Chemiluminescence method with potassium permanganate for the determination of organic pollutants in seawater. ANAL SCI 2001; 17:975-8. [PMID: 11708103 DOI: 10.2116/analsci.17.975] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A chemiluminescence method with potassium permanganate was developed for use as an indicator of organic pollutants in fresh water. This method could be applied to the determination of organic pollutants in seawater as well. However, the flow chemiluminescence method suffered from the interference of chloride ions at the same concentration of seawater because of the production of manganese dioxide in the oxidation of chloride ions with permanganate. The conditions (concentrations of potassium permanganate and sulfuric acid and sample volume, i.e. flow injection method) were chosen to minimize the interference of chloride ions. The chemiluminescence method shows a good correlation with the chemical oxygen demand method on fresh water added artificial sea salt and seawater samples. Natural seawater was analyzed by the chemiluminescence method. The results obtained were compared with those obtained by chemical oxygen demand under the alkaline condition and total organic carbon methods. The chemiluminescence method has higher sensitivity and reproducibility than the conventional chemical oxygen demand and total organic carbon methods.
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286
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Li L, Wu Z, Ma W, Yu Y, Chen Y. Changes in intestinal microflora in patients with chronic severe hepatitis. Chin Med J (Engl) 2001; 114:869-72. [PMID: 11780370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE To investigate changes in intestinal microflora in patients with chronic severe hepatitis (CSH), and their role in this life-threatening disease. METHODS We classified nineteen patients with chronic severe hepatitis as the CSH group, thirty patients with chronic hepatitis (CH) as the CH group and thirty-one healthy volunteer as the control group. Fecal flora from all subjects were analyzed. Concentrations of plasma endotoxin, serum cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) and liver function were assessed. RESULTS The number of fecal bifidobacterium (P < 0.001, P < 0.05 respectively), as well as bacteroidaceae (P < 0.001, P < 0.01 respectively) were significantly deceased in patients with chronic severe hepatitis compared with the CH and control groups, while the number of enterobacteriaceae (P < 0.001, P < 0.05 respectively) and yeasts (P < 0.01, P < 0.05 respectively) were significantly increased. Levels of plasma endotoxin, serum TNF-alpha, IL-1 beta and total bilirubin (TBiL) were significantly increased in the CSH group. The concentration of endotoxin positively correlated with levels of both TNF-alpha, IL-1 beta and TBiL (P < 0.001, respectively). Levels of plasma endotoxin were positively correlated with the number of fecal enterobacteriaceae and negatively correlated with bifidobacterium (P < 0.05, P < 0.001, respectively). CONCLUSION Intestinal flora in patients with chronic severe hepatitis were severely disturbed and gut microbiological colonization resistance was impaired. Changes in intestinal flora may have a pivotal role in both the elevation of plasma endotoxin and further hepatic lesions resulting in liver failure.
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287
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Ma W, Feng B, Tao Q. Murine antibody against E2 can capture hepatitis C virus in vitro. Chin Med J (Engl) 2001; 114:860-3. [PMID: 11780368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE To find neutralizing antibody candidates against hepatitis C virus (HCV) infection. METHODS We constructed two eukaryotic expression vectors which contained the E1 and E2 gene of HCV, and detected their expression in mammalian cells with transient expression. BALB/c mice were given subculaneous injections of constructed vectors combined with the IL-2 gene intraepidermally and evaluated for induced humoral immune responses by enzyme-linked immunosorbent assay (ELISA). We used an antibody-virus interaction assay to analyze the interaction of the antisera and HCV viral particles in vitro. RESULTS Anti E1 and anti-E2 antisera were obtained from immunized mice. The serum of mice immunized with the E2 gene immunoprecipitated the HCV isolate in source serum and reacted with the isolates unrelated to the original one. CONCLUSIONS Anti-E2 antibody in induced mice can cross-reactively capture HCV particles, highlighting the possibility of generating broadly reactive anti-E2 antibodies.
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288
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Xia C, Ma W, Stafford LJ, Marcus S, Xiong WC, Liu M. Regulation of the p21-activated kinase (PAK) by a human Gbeta -like WD-repeat protein, hPIP1. Proc Natl Acad Sci U S A 2001; 98:6174-9. [PMID: 11371639 PMCID: PMC33441 DOI: 10.1073/pnas.101137298] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The family of p21-activated protein kinases (PAKs) is composed of serine-threonine kinases whose activity is regulated by the small guanosine triphosphatases (GTPases) Rac and Cdc42. In mammalian cells, PAKs have been implicated in the regulation of mitogen-activated protein cascades, cellular morphological and cytoskeletal changes, neurite outgrowth, and cell apoptosis. Although the ability of Cdc42 and Rac GTPases to activate PAK is well established, relatively little is known about the negative regulation of PAK or the identity of PAK cellular targets. Here, we describe the identification and characterization of a human PAK-interacting protein, hPIP1. hPIP1 contains G protein beta-like WD repeats and shares sequence homology with the essential fission yeast PAK regulator, Skb15, as well as the essential budding yeast protein, MAK11. Interaction of hPIP1 with PAK1 inhibits the Cdc42/Rac-stimulated kinase activity through the N-terminal regulatory domains of PAK1. Cotransfection of hPIP1 in mammalian cells inhibits PAK-mediated c-Jun N-terminal kinase and nuclear factor kappa B signaling pathways. Our results demonstrate that hPIP1 is a negative regulator of PAK and PAK signaling pathways.
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289
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Zhang D, Zhang J, Ma W, Chen D, Han H, Shu H, Liu G. Analysis of trace amino acid neurotransmitters in hypothalamus of rats after exhausting exercise using microdialysis. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 758:277-82. [PMID: 11486837 DOI: 10.1016/s0378-4347(01)00187-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A simple but effective coupling of microdialysis and capillary electrophoresis with laser induced fluorescence detection technique was applied to analysis of amino acid neurotransmitters in the hypothalamus of rats after acute exhausting exercise. The separation of amino acids was achieved using an uncoated fused-silica capillary (57 cm x 75 microm I.D.) with a buffer of 10 mM disodium tetraborate at pH 10 and an applied voltage of 12.5 kV. The detection limit was 10(-10) M for each amino acid. It is sufficiently sensitive and rapid for the determination of amino acids in a 5-microl Microdialysate. In comparison to pre-exercise, a significant increase in the levels of six hypothalamic amino acids (arginine, glycine, lysine, glutamic acid, alanine, gamma-amino-n-butyric acid) was found after exercise. These results demonstrate that the increase of metabolic amino acids in the hypothalamus of rats can be induced by exhausting exercise and suggests that amino acid neurotransmitters may play functional roles in the central effects of exercise.
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290
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Sam M, Vora S, Malnic B, Ma W, Novotny MV, Buck LB. Neuropharmacology. Odorants may arouse instinctive behaviours. Nature 2001; 412:142. [PMID: 11449261 DOI: 10.1038/35084137] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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291
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Zhang L, Rubinow DR, Xaing G, Li BS, Chang YH, Maric D, Barker JL, Ma W. Estrogen protects against beta-amyloid-induced neurotoxicity in rat hippocampal neurons by activation of Akt. Neuroreport 2001; 12:1919-23. [PMID: 11435923 DOI: 10.1097/00001756-200107030-00030] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The cellular mechanisms underlying the neuroprotective effects of estrogen are only beginning to be elucidated. Here we examined the role of protein kinase B (Akt) activation in 17beta-estradiol (E2) inhibition of beta-amyloid peptide (31-35) (Abeta31-35)-induced neurotoxicity in cultured rat hippocampal neurons. Abeta31-35 (25-30 betaM) significantly decreased the total number of microtubule associated protein-2 positive cells (MAP2+). This decrease was significantly reversed by pre-treatment with 100 nM E2. Further, 100 nM E2 alone significantly increased the total number of protein kinase B and microtubule associated protein-2 positive cells compared with controls. Such E2-induced increases were inhibited by LY294002 (20 microM), a specific PI3-K inhibitor, as well as by tamoxifen, an estrogen receptor antagonist/selective estrogen receptor modulator. These results indicate that the neuroprotective effects of E2 may be mediated at least in part via estrogen receptor-mediated protein kinase B activation.
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Carper D, John M, Chen Z, Subramanian S, Wang R, Ma W, Spector A. Gene expression analysis of an H(2)O(2)-resistant lens epithelial cell line. Free Radic Biol Med 2001; 31:90-7. [PMID: 11425494 DOI: 10.1016/s0891-5849(01)00561-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Gene expression patterns were examined in lens epithelial cells conditioned to grow in 125 microM hydrogen peroxide in order to define the protective mechanisms that may be involved in survival during oxidative stress. RNA was extracted from normal and hydrogen peroxide-resistant alphaTN4 mouse lens epithelial cells. Gene expression was evaluated using Differential Display (DD) and RT-PCR. Upregulation of mRNAs for antioxidant and cellular defense enzymes was observed. The highest elevation detected was a 14-fold increase in catalase in the hydrogen peroxide-resistant cells. Glutathione peroxidase, ferritin, and alphaB-crystallin were upregulated 2-fold, and reticulocalbin was upregulated 6-fold in the resistant cells. alphaA-crystallin was downregulated 5-fold, while aldose reductase and mitochondrial gene products were unchanged. Thus, in the alphaTN4 mouse lens cell line, long-term exposure to high levels of hydrogen peroxide elicited an upregulation of transcripts for enzymes involved in hydrogen peroxide degradation, metal binding, and chaperone function. Since mitochondrial gene transcription is sensitive to hydrogen peroxide, the presence of normal levels of mitochondrial transcripts, in this study, demonstrates the effectiveness of the antioxidant defense systems.
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Sun H, Chen L, Yue Z, Sun G, Ma W. [Measurement of chlorodifluoromethane(HCFC-22) in the atmosphere by using an O2-induced electron capture detector (ECD)]. HUAN JING KE XUE= HUANJING KEXUE 2001; 22:21-4. [PMID: 11569107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Chlorodifluoromethane (CHClF2, HCFC-22), a typical substitute of dichlorodifluoromethane(CF2Cl2, CFC-12), which atmospheric concentration was only at 10(-12) V/V level. After preconcentrated air sample, O2-Induced method was used to enhance sensitivity of ECD response to HCFC-22. When O2 concentration in carrier gas was 0.54%, there was the greatest value of S/N(signal to noise) and ECD response increased by about 500 times. With the study of other conditions, such as selection of the ECD temperature, programing of the column oven temperature and carrier gas flow, a practicable analysis method with high sensitivity of ECD was established.
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294
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Tian Y, Ma W, Zhang Y. [Influence of cytokine gene polymorphism on renal transplantation]. ZHONGHUA YI XUE ZA ZHI 2001; 81:719-21. [PMID: 11798953] [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 investigate the influence of cytokine gene polymorphism on renal transplantation. METHODS The cytokine genotypes of cytokines TNF-alpha, IL-10, TGF-beta(1), and L-6 among 91 consecutive kidney recipients were detected by PCR-SSP. The distribution frequencies of different cytokine genotypes and the influence of cytokine gene polymorphism on renal transplantation were analyzed. RESULTS Among the 91 renal recipients, the dominant genotypes of IL-10 and TNF-alpha were low producer genotype with the frequencies of 90.1% and 79.1% respectively; and the dominant genotypes of TGF-beta(1) and IL-6 were high producer genotypes (79.1% and 100% respectively). The kidney recipients with TNF-alpha high producer genotype and IL-10 high or intermediate producer genotype were associated with more acute rejection episodes than those with low producer genotypes. The acute rejection episodes in the kidney recipients with IL-10 high or intermediate producer genotype were mainly vascular acute rejection. CONCLUSION The cytokine gene polymorphism has significant influence on incidence and severity of acute rejection after renal transplantation. Detecting the cytokine genotype before renal transplantation is beneficial to predict the outcome of transplantation accurately.
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295
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Pancrazio JJ, Keefer EW, Ma W, Stenger DA, Gross GW. Neurophysiologic effects of chemical agent hydrolysis products on cortical neurons in vitro. Neurotoxicology 2001; 22:393-400. [PMID: 11456340 DOI: 10.1016/s0161-813x(01)00028-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The neurophysiologic effects of chemical agent hydrolysis products were examined on cultured cortical neurons using multielectrode array (MEA) recording and the whole-cell patch clamp technique. Measurement of neuronal network extracellular potentials showed that the primary hydrolysis product of soman, pinacolyl methylphosphonic acid (PMPA), inhibited network mean burst and spike rates with an EC50 of approximately 2 mM. In contrast, the degradation product of sarin, isopropyl methylphosphonic acid (IMPA), and the final common hydrolysis product of both soman and sarin, methylphosphonic acid (MPA), failed to affect neuronal network behavior at concentrations reaching 5 mM. Closer examination of the effects of PMPA (2 mM) on discriminated extracellular units revealed that mean spike amplitude was slightly diminished to 95 +/- 1% (mean +/- S.E.M., n = 6, P < 0.01) of control. Whole-cell patch clamp records under current clamp mode also showed a PMPA-induced depression of the firing rate of spontaneous action potentials (APs) to 36 +/- 6% (n = 5, P < 0.001) of control. In addition, a minor depression with exposure to PMPA was observed in spontaneous and evoked AP amplitude to 93 +/- 3% (n = 5, P < 0.05) of control with no change in either the baseline membrane potential or input resistance. Preliminary voltage clamp recordings indicated a reduction in the occurrence of spontaneous inward currents with application of PMPA. These findings suggest that PMPA, unlike MPA or IMPA, may more readily interfere with one or more aspects of excitatory synaptic transmission. Furthermore, the data demonstrate that the combination of extracellular microelectrode array and patch clamp recording techniques facilitates analysis of compounds with neuropharmacologic effects.
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Shi X, Ma W, Sun C, Wu S. The aggregation behavior of collagen in aqueous solution and its property of stabilizing liposomes in vitro. Biomaterials 2001; 22:1627-34. [PMID: 11374464 DOI: 10.1016/s0142-9612(00)00320-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The aim of this study is to acquire the relationship between the aggregation behavior of collagen in aqueous solution and its property of stabilizing liposomes in vitro. Firstly, we used an intramolecular charge transfer compound 3-methoxy-4'-N,N-dimethylamino flavone derivative (DMMF) as a fluorescence probe to detect collagen association in aqueous solution. Results showed that, when collagen concentration was increased to 0.5 mg/ml or above, the fluorescence intensity of DMMF at 465 nm increased dramatically. This indicated that collagen could associate in aqueous solution. The subsequent fluorescence polarization study on the same collagen solutions also proved that the aggregation behavior existed in the aqueous solution of collagen. Secondly. to evaluate the in vitro stability of small unilamellar vesicles (SUV), made from soybean phosphatidylcholine (PC) and coated with collagen, 5(6)-carboxyfluorescein was used as a fluorescence probe to determine the change of their permeability. We found that the coating with a collagen/PC weight ratio of 2:1, significantly decreased the permeability of liposomal membranes. The likely weight ratio of collagen and PC was mainly dependent on the critical aggregation concentration of collagen in aqueous solution. In addition, the fluorescence polarization method was also used to study the influence of a coating with collagen at the above ratio on the fluidity of liposomal membranes, employing DMMF as a fluorescence probe. The fluidity of liposomal membranes coated with collagen showed no obvious change, indicating that SUV coated with collagen at an appropriate ratio, could significantly improve the in vitro stability of liposomal membranes without disturbing their fluidity. It is thus clear that collagen self-association behavior is closely correlated to its coating liposomes to improve their stability.
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Abstract
We studied the results of 245 valgus producing high tibial osteotomies performed with the use of an opening wedge technique and rigid internal fixation followed by early passive and active motion of the knee. Previous studies have used iliac bone grafts or hemicollastasis held by an external fixator for opening the osteotomy. In our series the opening was obtained by a block of cement interposed in the postero-medial part of the osteotomy. This series confirms that the opening wedge osteotomy allows good accuracy for the correction. Ninety-three percent of the knees had a correction adjusted between 180 and 187 degrees for the hip-knee-ankle angle. Survivorship analysis showed an expected rate of survival, with conversion to a total knee on the end point, of 94% at 5 years, 85% at 10 years and 68% at 15 years. Conversion to a total knee arthroplasty was accomplished without difficulty in the patients who had this procedure done. We recommend opening wedge tibial osteotomy with acrylic cement bone cement as bone substitute, rigid internal fixation, and early motion for patients who undergo high tibial osteotomy.
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298
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Nomura M, Kaji A, Ma W, Miyamoto K, Dong Z. Suppression of cell transformation and induction of apoptosis by caffeic acid phenethyl ester. Mol Carcinog 2001; 31:83-9. [PMID: 11429785 DOI: 10.1002/mc.1043] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Caffeic acid phenethyl ester (CAPE), which is derived from the propolis of honeybee hives, has been shown to block tumor promotion and to have toxic effects on several cancer cells. The mechanism of the anti-tumor promotion activity of CAPE is unclear, however. In this study, we found that CAPE suppressed 12-O-tetradecanoylphorbol-13-acetate-induced cell transformation and induced apoptosis in mouse epidermal JB6 Cl 41 cells. No difference in induction of apoptosis was observed between normal lymphoblasts and sphingomyelinase-deficient cell lines. Although CAPE treatment of two p53 mutant tumor cell lines, NCI-H358 and SK-OV-3, and p53-deficient (p53(-/-)) cells caused the cleavage of caspase-3 as well as DNA fragmentation, caspase-3 cleavage was seen early (at 6 h) only in cells expressing wild-type p53 (p53(+/+)) and Cl 41 cells. These results suggested that p53 may be involved in the early stage of CAPE-induced apoptosis. The p53-dependent transcription activation occurred 2 h after treatment with CAPE and reached a maximum at 6 h in Cl 41 p53 DNA-binding sequence stable transfectant cells. In addition, phosphorylation of p53 at serine 15 and serine 392 was induced in Cl 41 cells within 6 h after treatment with CAPE. Therefore, CAPE may induce apoptosis through p53-dependent and p53-independent pathways and its anti-tumor promotion activity may have occurred through the induction of apoptosis.
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299
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Wang J, Ma W. [The diagnosis and treatment of large cervical vascular injury]. ZHONGHUA ER BI YAN HOU KE ZA ZHI 2001; 36:224-6. [PMID: 12761931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
OBJECTIVE To study the diagnosis and treatment of large cervical vascular injury, and to improve the treatment. METHODS Clinical data of 18 cases of large cervical vascular injury between 1974 and 1999 in the Medical College Second Affiliated Hospital of Zhejiang University were analyzed retrospectively. RESULTS The following injuries were found, including common carotid artery involvement in 7, external carotid artery in 4, internal carotid artery in 2, subclavian artery in 1, internal jugular vein in 4. The type of injury included incision injury in 8, laceration injury in 5, break injury in 2, inflammatory injury in 2, tumor injury in 1. Fifteen cases were diagnosed by active bleeding of wound in neck, 2 cases by color Duplex ultrasound, 1 case by exploration. Operation included vascular repair in 8, vascular ligation in 10. The result showed that 14 patients were cured, one patient developed light hemiplegia, one patient performed amputation of the arm due to necrosis after subclavian artery ligation, two patients died, the mortality rate was 11.1%. CONCLUSION Active profuse bleeding from the neck wound is the basis of diagnosis basis. Rational surgical treatments are needed immediately.
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Zhang X, Chen J, Peng Q, Wang D, Ma W, Dai S, Chen D. [Analysis of the lineshape of laser frequency modulation]. GUANG PU XUE YU GUANG PU FEN XI = GUANG PU 2001; 21:257-262. [PMID: 12947640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this paper, we analyze the dependence of the output signal spectral lineshape and intensity on the modulation, waveform and modulation index in first- and second-harmonic detection of triangle modulation, square demodulation and saw modulation square demodulation. The signal lineshape in the case of saw modulation, square demodulation is quite different from, whereas the signal lineshape in the case of triangle modulation, square demodulation is similar to that in traditional sine modulation, sine demodulation. Experiments of tunable IR laser frequency modulation absorption spectrum of methane are also done to verify the theoretical analysis. Then we reach a conclusion; the lineshape and intensity of frequency modulation spectrum can be influenced by modulation waveform, demodulation waveform and modulation index. Calculation results can be used to choose better experimental parameters and optimize experimental designs.
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