176
|
Nie Y, Schoepp DD, Klaunig JE, Yard M, Lahiri DK, Kubek MJ. Thyrotropin-releasing hormone (protirelin) inhibits potassium-stimulated glutamate and aspartate release from hippocampal slices in vitro. Brain Res 2005; 1054:45-54. [PMID: 16055093 DOI: 10.1016/j.brainres.2005.06.077] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Revised: 06/17/2005] [Accepted: 06/25/2005] [Indexed: 10/25/2022]
Abstract
Excess excitatory amino acid release is involved in pathways associated with seizures and neurodegeneration. Thyrotropin-releasing hormone (TRH; protirelin), a brain-derived tripeptide, has shown efficacy in the treatment of such disorders, yet its mechanism of neuroprotection is poorly understood. Using superfused hippocampal slices, we tested the hypothesis that TRH could inhibit evoked glutamate/aspartate release in vitro. Rat hippocampal slices were first equilibrated in oxygenated Krebs buffer (KRB) (120 min) then superfused for 10 min with KRB (control), or KRB containing 0.1, 1, or 10 microM TRH respectively, prior to and during 5 min depolarization with high potassium KRB (50 mM [K(+)] +/- TRH). Fractions (1 min) were collected during the 5 min stimulation and for an additional 10 min thereafter and analyzed for glutamate and aspartate by HPLC. TRH had no effect on baseline glutamate/aspartate release, while all three TRH doses significantly (P < 0.05) inhibited peak 50 mM [K(+)]-stimulated glutamate/aspartate release, and glutamate remained below control (P < 0.05) at 15 min post stimulation. A 5 min pulse of TRH (10 microM) had no affect on basal glutamate/aspartate release, whereas the TRH pre-pulsed slices failed to release glutamate/aspartate by [K(+)]-stimulation given 15 min later. These results are the first to show a potent and prolonged inhibitory effect of TRH on evoked glutamate/aspartate release in vitro. These initial studies suggest that exogenous and/or endogenous TRH may function, in part, to modulate excess glutamate release in specific CNS loci. Additional studies are in progress to fully understand the mechanism of this potent effect of TRH and its implication in various CNS disorders.
Collapse
|
177
|
Zeng H, Ge KY, Nie Y, Yan W, Yang XK. [Factors related to false positive results of treadmill electrocardiogram test for the detection of coronary heart disease]. ZHONGHUA NEI KE ZA ZHI 2004; 43:669-71. [PMID: 15500779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
OBJECTIVE To investigate the clinical factors related to false positive results of electrocardiogram treadmill exercise test (TET) for the detection of coronary heart disease (CHD). METHODS 258 patients with chest pain undergoing TET and coronary angiography (CAG) were on rolled. The case history and various clinical parameters were collected. (1) The results of TET and CAG were compared to evaluate the sensitivity, specificity and accuracy of TET; (2) Clinical informations of the true positive group and the false positive group were compared and a statistic analysis was carried out. RESULTS The sensitivity, specificity and accuracy of TET for diagnosing CHD was 77.3%, 65.9%, and 69.8% respectively. The number of female in the false positive group was larger than that in the true positive group; The number of patients with typical chest pain, hyperlipidemic history, smoking history and family history of CHD was smaller than that in the true positive group. In the false positive group, the change of ST segment was mainly in II, III, aVF. The number of patients with change of more than 0.2 mV in ST and with angina induced during exertion was lower in the false positive group than in the true positive group. The difference was significant. CONCLUSION Factors including sex, typical chest pain, risk factors of CHD, the location and extent of ECG changes and angina induced by exertion are closely related to false positive results of TET.
Collapse
|
178
|
Nie Y, Luo SQ. [The study of human brain soft-tissue deformations based on the finite element method]. ZHONGGUO YI LIAO QI XIE ZA ZHI = CHINESE JOURNAL OF MEDICAL INSTRUMENTATION 2002; 26:342-6. [PMID: 16104264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
This paper presents the recent progress of the study of human brain soft-tissue deformations based on finite element method. Some possible problems and issues about the implementation of the methods are also discussed.
Collapse
|
179
|
Pancook JD, Beuerlein G, Pecht G, Tang Y, Nie Y, Wu H, Huse WD, Watkins JD. In vitro affinity maturation of human IgM antibodies reactive with tumor-associated antigens. HYBRIDOMA AND HYBRIDOMICS 2002; 20:383-96. [PMID: 11839257 DOI: 10.1089/15368590152740798] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Human lymphocytes secreting tumor cell-specific IgM antibodies were enriched in vitro following the stimulation of allogeneic human splenocytes from nontumor-bearing donors with cytostatic tumor cells or tumor cell plasma membrane fractions. The antibodies were generally of the IgM class and displayed low intrinsic affinity (K(d) > 100 nM). Nonetheless, the avidity arising from multivalent binding sites permitted the identification of multiple monoclonal antibodies (MAbs) displaying specificity for cultured tumor cells. Five antibodies were cloned from the B cells and two of these were expressed as human Fabs with IgG(1) constant regions. Although the avidity of the human IgM antibodies was sufficient to permit detection in the original screening, the monovalent Fabs displayed low binding activities, consistent with their low intrinsic affinity. Thus, in vitro affinity maturation was used to rapidly generate multiple variants of both antibodies displaying greater than 100-fold higher affinity. Two of the antibodies were characterized further and shown to have distinct specificities. One of the targets, LH11238, is associated both with the plasma membrane and with lysosomes and is rapidly internalized following incubation of the antibody with intact live cell monolayers. The second antigen, designated LH13, is a secreted antigen that has been enriched 200-fold from conditioned media and consists of two reactive bands at 42 and 45 kDa on denaturing Western blots. The stimulation and enrichment of human lymphocytes in culture coupled with rapid in vitro affinity maturation of low affinity antibodies potentially enables the discovery of human antibodies to a broader range of epitopes, including those that might be of greater therapeutic relevance.
Collapse
|
180
|
Nakashima M, Nie Y, Li QL, Friedman TC. Up-regulation of splenic prohormone convertases PC1 and PC2 in diabetic rats. REGULATORY PEPTIDES 2001; 102:135-45. [PMID: 11730986 DOI: 10.1016/s0167-0115(01)00311-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Organisms respond to infection in a complex manner involving bidirectional interactions between the neuroendocrine and immune systems. Many of the bioactive endocrine/immune factors are synthesized in a precursor form and are expected to be activated by prohormone convertases (PCs). Since patients with both type 1 and type 2 diabetes have an increased incidence and severity of infections, we hypothesized that in a condition of hyperglycemia, these processing enzymes would be activated in an immune tissue, the spleen. To test this hypothesis, we treated rats with intraperitoneal streptozotocin (STZ) (50 mg/kg/day) daily for 5 days and measured splenic PC1 and PC2 mRNA by ribonuclease protection assay. We found that PC1 mRNA was increased 6.0+/-0.02-fold (P<0.05) and PC2 mRNA was increased 1.80+/-0.01-fold (P<0.005) in the spleen of rats that received STZ compared to rats that received vehicle. Western blot indicated that the 75-kDa form of PC1 was the only form of PC1 present in the spleen and that this form increased with STZ treatment. Immunohistochemistry revealed that PC1 was found in both the white pulp (T-lymphocytes) and red pulp (monocytes and macrophages) and that its increase in immunoreactivity occurred primarily in the white pulp. PC2 and pro-opiomelanocortin (POMC, a possible splenic substrate for PC1/PC2) immunoreactivity was found predominantly in the red pulp. STZ induced an increase in splenic PC1 and POMC, but not PC2 protein levels. We conclude that in the STZ model of diabetes, splenic PCs are induced, which could lead to an increased activation of many immune-derived hormones. We speculate that this up-regulation of prohormone converting enzymes may be related to the increased infections seen in patients with both type 1 and type 2 diabetes.
Collapse
|
181
|
Nie Y, Yang G, Song Y, Zhao X, So C, Liao J, Wang LD, Yang CS. DNA hypermethylation is a mechanism for loss of expression of the HLA class I genes in human esophageal squamous cell carcinomas. Carcinogenesis 2001; 22:1615-23. [PMID: 11577000 DOI: 10.1093/carcin/22.10.1615] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The three human leukocyte antigen (HLA) class I antigens, HLA-A, HLA-B and HLA-C, play important roles in the elimination of transformed cells by cytotoxic T cells. Frequent loss of expression of these antigens at the cell surface has been observed in many human cancers. Various mechanisms for post-transcriptional regulation have been proposed and tested but the molecular mechanisms for transcriptional regulation are not clear. We show by immunohistochemistry that the HLA class I antigens are absent in 26 of 29 (89%) samples of human esophageal squamous cell carcinomas (ESCC). Eleven of the 26 ESCC samples lost mRNA expression for at least one of the HLA genes, as shown by RT-PCR. DNA from the 29 pairs of ESCC and neighboring normal epithelium were examined for CpG island hypermethylation, homozygous deletion, microsatellite instability (MSI) and loss of heterozygosity (LOH). DNA from normal epithelial tissues had no detectable methylation of the CpG islands of any of these gene loci. Thirteen of 29 ESCC samples (45%) exhibited methylation of one or more of the three HLA loci and six samples (21%) exhibited methylation of all three loci. The HLA-B gene locus was most frequently methylated (38%). HLA-B mRNA expression in an ESCC cell line, where HLA-B was hypermethylated and did not express mRNA, was activated after treatment with 5-aza-2'-deoxycytidine. Homozygous deletion of these three gene loci was not observed. Relatively low rates of LOH and MSI were observed for the microsatellite markers D6S306, D6S258, D6S273 and D6S1666, close to the HLA-A, -B and -C loci, although a high ratio of LOH was observed at a nearby locus (represented by the markers D6S1051 and D6S1560), where the tumor suppressor gene p21(Waf1) resides. A strong correlation between genetic alterations and mRNA inactivation was observed in the ESCC samples. Our results indicate that HLA class I gene expression was frequently down-regulated in ESCC at both the protein and mRNA levels and that hypermethylation of the promoter regions of the HLA-A, -B and -C genes is a major mechanism of transcriptional inactivation.
Collapse
|
182
|
Nie Y, Hu CH, Li X, Yong W, Dou JM, Sun J, Jin RS, Zheng PJ. Three monoalkoxy-substituted nido-platinaboranes: [(PPh3)2PtB10H11-8-(OCH3)], [(PPh3)2PtB10H11-8-[OCH-(CH3)2]] and [(PPh3)2PtB10H10-9-[OCH(CH3)2]]. Acta Crystallogr C 2001; 57:897-9. [PMID: 11498605 DOI: 10.1107/s0108270101007788] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2001] [Accepted: 05/10/2001] [Indexed: 11/10/2022] Open
Abstract
Each of the title compounds, 8-methoxy-7,7-bis(triphenylphosphine-P)-8,9:10,11-di-muH-7-platina-nido-undecaborane dichloromethane hemisolvate, [Pt(CH(14)B(10)O)(C(18)H(15)P)(2)].0.5CH(2)Cl(2), (I), 8-isopropoxy-7,7-bis(triphenylphosphine-P)-8,9:10,11-di-muH-7-platina-nido-undecaborane dichloromethane solvate, [Pt(C(3)H(18)B(10)O)(C(18)H(15)P)(2)].CH(2)Cl(2), (II), and 9-isopropoxy-7,7-bis(triphenylphosphine-P)-8,9:10,11-di-muH-7-platina-nido-undecaborane dichloromethane solvate, [Pt(C(3)H(18)B(10)O)(C(18)H(15)P)(2)].CH(2)Cl(2), (III), has an 11-vertex nido polyhedral skeleton, with the 7-platinum centre ligating to two exo-polyhedral PPh(3) groups and an alkoxy-substituted polyhedral borane ligand. Compounds (II) and (III) are isomers. The Pt-B distances are in the range 2.214 (7)-2.303 (7) A for (I), 2.178 (16)-2.326 (16) A for (II) and 2.205 (6)-2.327 (6) A for (III).
Collapse
|
183
|
Nie Y, Ke Y, Chen J, Ding M. [Construction of the full-length cDNA clone of Chinese virulent strain--F114]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 2001; 41:452-6. [PMID: 12552911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Seven subclones covered the complete genome of classical swine fever virus Chinese virulent strain F114 were obtained by reverse transcription PCR. The complete nucleotide sequence of the genome of strain F114 was determined by sequencing. The cDNA fragments were then assembled and inserted downstream of a T7 promoter in pBluescript II sk+ plasmid vector to obtain the full-length cD-NA clone sk-12297. Homology comparison of the nucleotide and amino acid sequence of strain F114 with the known sequences of HCLV, Brescia and Alfort showed 95.70%, 96.80%, 86.03% identity in nucleotide and 97.41%, 98.54%, 93.33% identity in amino acid respectively.
Collapse
|
184
|
Nie Y, Zhang J, Xi S, Yang Z. [Emissions of biogenic sulfur gases from wheat fields]. HUAN JING KE XUE= HUANJING KEXUE 2001; 22:25-8. [PMID: 11569108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Emission rates of carbonyl sulfide (COS), carbon disulfide (CS2) and dimethyl sulfide (DMS) to the atmosphere from wheat fields treated with different fertilizers were measured by using the closed chamber method. The results showed that the emission rate of COS, CS2 and DMS was affected by wheat growth and COS was absorbed by the plants. DMS and CS2 were the predominant sulfur gases emitted from these fields. The diurnal variations of emission rates of COS and CS2 were obvious. The sulfur flux in the plot treated with organic fertilizer was higher than that in the other plots. The sulfur fluxes from different plots were in the range of -1.40 to 0.79 mg.m-2.
Collapse
|
185
|
Nie Y, Li Y, Sha W, Dai S, She Q, Wu H. [Effect of octreotide on intragastric pH in patients with duodenal ulcer bleeding]. ZHONGHUA YI XUE ZA ZHI 2001; 81:520-2. [PMID: 11809113] [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 evaluate the effect of octreotide on the intragastric pH of patients with duodenal ulcer bleeding during the period of 24 hours and to observe if it can advance the effect of hemostasis by endoscopic injection of epinephrine. METHODS Twenty-four patients with duodenal ulcer bleeding were randomly divided into three groups, eight in each. Patients in group 1 received an intravenous injection of 0.1 mg of octreotide followed by continuous intravenous drip of octreotide at a constant speed of 25 microg/h for 24 hours. The patients in group 2 received an intravenous injection of 0.1 mg of octreotide followed by continuous intravenous drip of octreotide at a constant speed of 42 microg/h for 24 hours. The patients in group 3 received an intravenous injection of 40 mg of omeprazole followed by continuous intravenous drip of omeprazole at a constant speed of 8 mg/h for 24 hours. Intragastric pH was continuously recorded with a pH meter. The patients with active ulcer bleeding was treated with injection of epinephrine via endoscope and then received intravenous drip of octreotide (with the same dosage as in group 1, n = 42) or omeprazole (with the same dosage as in group 3, n = 54) for 72 hours and were given omeprazole (20 mg Bid). RESULTS The mean and median intragastric pH values among the patients in group 2 treated by a larger dosage of octreotide (6.7 +/- 0.5 and 6.9 +/- 0.4) were similar to those in the group 3 treated by omeprazole (6.8 +/- 0.4 and 7.0 +/- 0.4). There was no statistically significant difference between these two groups in percentage of intragastric pH above 4, 6, and 7 The mean and median of intragastric pH among the patients in group 1 treated by a smaller dosage of octreotide were statistically significantly smaller (5.2 +/- 0.5 and 5.4 +/- 0.4) than those in the omeprazole group. There was no statistically significant difference between octreotide treatment and omeprazole treatment in terms of volume of blood transfusion (0.7 +/- 0.5 vs. 0.6 +/- 0.4 L), rebleeding rate (11.6% vs. 12.9%), emergency operation rate (7.1% vs. 3.7%), and mortality (2.3% vs. 3.7%). CONCLUSION Octreotide effectively inhibits the secretion of gastric acid. However, the dosage in common use clinically fails to increase the intragastric pH to the best situation needed for effective hemostasis. Only a large dosage (1.10 mg/d) works.
Collapse
|
186
|
Guo F, Sun W, Wang D, Zhao L, Lu Z, Nie Y. Optical limiting of pentaazadentate metal complexes for picosecond pulses in solution. APPLIED OPTICS 2001; 40:1386-1388. [PMID: 18357126 DOI: 10.1364/ao.40.001386] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The optical-limiting performances for four pentaazadentate metal complexes in tetrahydrofuran have been measured at 532 nm for 35-ps pulses, in which reverse saturable absorption from the singlet-singlet excited states should be responsible for the limiting mechanism. The excited-state parameters are calculated according to a six-level model. The limiting threshold at T/T0 = 0.5. is 44 mJ/cm2, and the throughput is limited to 27 mJ/cm2 as incident fluence reaches 0.35 J/cm2 for carboxyl pentaazadentate cadmium. The limiting thresholds and the throughput values are strongly influenced by peripheral substituents and central metal ions of the complexes.
Collapse
|
187
|
Wang H, Nie Y. Remedial strategies for municipal solid waste management in China. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2001; 51:264-272. [PMID: 11256501 DOI: 10.1080/10473289.2001.10464264] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The purpose of this investigation is to evaluate the current status and to identify the problems of municipal solid waste (MSW) management in China to determine appropriate remedial strategies. This is the second of two papers proposed on this topic. Major problems or difficulties identified in MSW management in China include MSW land, air, and water pollution, commingled collection, poor administration, shortage of funds, lack of facilities, and problems of training and public awareness. In order to solve these problems and to improve MSW management in China, remedial strategies in three areas are recommended: institutional reform, technology development, and legislation and administrative improvement. The primary principle involved in institutional reform is unifying legislative responsibilities into one body and developing a market mechanism for handling MSW. Composting, landfills, and incineration should be equally developed in accordance with China's needs. The feasibility of developing technology to handle MSW in China is discussed. Also recommended is the establishment of sound regulatory systems, including a service fee system, a source separation system, and a training program. China is presently undergoing economic and institutional reform at the national and local levels. Results of this study will provide useful information on MSW management in China.
Collapse
|
188
|
Wang H, Nie Y. Municipal solid waste characteristics and management in China. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2001; 51:250-263. [PMID: 11256500 DOI: 10.1080/10473289.2001.10464266] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The purpose of this investigation is to evaluate the current status and identify the problems of municipal solid waste (MSW) management in China in order to determine appropriate remedial strategies. This is the first of two papers, discussing primarily the general characteristics of MSW and its management in China. The second paper focuses on specific remedial strategies. MSW generation in China has increased rapidly in the past 20 years from 31.3 million tons in 1980 to 113.0 million tons in 1998. The annual rate of increase is 3-10%. The average generation per capita is 1.0 kg/day (0.38 t/year). Nearly one-half of the waste generated is dumped in the suburbs, where the accumulated quantity has reached 6 billion tons, which has caused heavy environmental pollution. This paper provides information on MSW management in China, such as MSW generation and its physical, chemical, and biological properties. Low calorific value and high moisture content characterize China's municipal waste. Other issues related to MSW management in China are also discussed, including the factors that influence MSW generation quantity and
Collapse
|
189
|
He F, Nie Y, Han Z. [Production of phage-displayed anti-idiotypic antibody single chain variable fragments to MG7 monoclonal antibody directed against gastric carcinoma]. ZHONGHUA YI XUE ZA ZHI 2001; 81:33-6. [PMID: 11798849] [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 generate phage-displayed anti-idiotypic antibody single chain variable fragments (anti-Id ScFv) MG7 to monoclonal antibody directed against gastric carcinoma so as to lay a foundation for developing anti-Id ScFv vaccine of the cancer. METHODS Balb/c mice were immunized i.p. with purified MG7 monoclonal antibody conjugated with keyhole limpet hemocyanin. mRNA was isolated from the spleens of immunized mice. Heavy and light chain genes (VH and VL) of antibody were amplified separately and assembled into ScFv genes with a specially constructed linker DNA by RT-PCR. The ScFv genes were ligated into the phagemid vector pCANTAB5E and the ligated sample was transformed into competent E. coli TG1. The transformed cells were infected with M13KO7 helper phage to yield recombinant phage, which displayed ScFv fragments as a fusion with gene 3 protein on the tips of M13 phage. After four rounds of panning with monoclonal antibody MG7, the MG7-positive clones were selected with the enzyme-linked immunosorbent assay (ELISA) from the enriched phages. The types of the anti-Id ScFv displayed on the selected phage clones were primarily identified by competition ELISA. RESULTS The VH, VL and ScFv DNAs were about 340, 320 and 750 bp respectively. Twenty-four MG7-positive clones were selected from 40 enriched phage clones. Five of the 24 clones displayed beta or gamma type anti-Id ScFv. CONCLUSION The anti-Id ScFv frangments to MG7 monoclonal antibody can be successfully selected by recombinant phage antibody technique, which paves a way for the study of prevention and cure of gastric carcinoma using anti-Id ScFv.
Collapse
|
190
|
He F, Chen B, Nie Y, Han Z, Qiao T, Fan D. [Production of phage-displayed single chain variable fragments of monoclonal antibody MGb1]. ZHONGHUA NEI KE ZA ZHI 2000; 39:585-7. [PMID: 11798521] [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 lay a foundation for obtaining a tumor-targeting vehicle for in vivo study on diagnosis and treatment of gastric carcinoma by generating single chain variable fragments (ScFv) of monoclonal antibody MGb1 directed against the cancer. METHODS mRNA was isolated from MGb1-producing mouse hybridoma cell line, and the variable regions of heavy and light chain cDNAs were amplified separately and assembled into ScFv DNAs with a specially constructed linker DNA by PCR. The ScFv DNAs were ligated into the phagemid vector pCANTAB5E and the ligated sample was transformed into competent E. coli TG1. The transformed cells were infected with M13KO7 helper phage to yield recombinant phage, which display ScFv fragments as a fusion with gene 3 protein on the tips of the phage M13. After two rounds of panning with gastric carcinoma cell line KATO III highly expressing MGb1-binding antigen, the phage clones displayed ScFv fragments of the antibody were selected by enzyme-linked immunosorbent assay (ELISA) from the enriched phages. The affinity of the positive phage clones was detected by competition ELISA. RESULTS The VH, VL and ScFv DNAs were about 340 bp, 320 bp and 750 bp respectively. 17 phage clones displayed ScFv of MGb1 were selected from 40 enriched phage clones. 4 out of the 17 phage clones could strongly compete with the original hybridoma antibody MGb1 for binding to the antigen expressed on KATOIII cells. CONCLUSION The phage-displayed ScFv fragments of monoclonal antibody MGb1 are successfully produced by phage antibody technology, which may be useful to widen the range of application of the antibody.
Collapse
|
191
|
Cai YC, Yang GY, Nie Y, Wang LD, Zhao X, Song YL, Seril DN, Liao J, Xing EP, Yang CS. Molecular alterations of p73 in human esophageal squamous cell carcinomas: loss of heterozygosity occurs frequently; loss of imprinting and elevation of p73 expression may be related to defective p53. Carcinogenesis 2000; 21:683-9. [PMID: 10753204 DOI: 10.1093/carcin/21.4.683] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
p73 is structurally and functionally related to p53 and is possibly a tumor suppressor gene. Using 15 surgically resected frozen esophageal specimens containing both squamous cell carcinomas (ESCC) and neighboring normal epithelia, we studied p73 gene alterations and mRNA expression. Loss of heterozygosity of the p73 loci was found in nine of 14 informative cases (64%). A polymorphism at codon 173 (Thr) of p73 was identified (eight samples had ACC and seven had ACT), but mutation was not detected in tumor samples. Nine of the 15 ESCC samples (60%) displayed significantly elevated expression of p73 over the neighboring normal epithelium; of these nine samples, four displayed loss of imprinting (LOI) and one switched the expressed allele. Hypermethylation of exon 1 of the p73 gene was not detected, using the bisulfite modification method, in normal or tumor samples. Twelve of the 15 (80%) ESCC samples contained p53 defects, including missense mutation, non-frameshift small deletion or insertion, non-detectable transcripts and protein accumulation. The ESCC samples with p53 defects were significantly correlated with those which had elevated expression of p73 (Fisher's exact test, P < 0.05). The results suggest that increased expression of p73, including that by LOI, could be a partial compensatory mechanism for defective p53.
Collapse
|
192
|
Shi M, Liang Z, Du X, Jiang X, Nie Y. [A molecular epidemiological investigation on Leptospira interrogans serovar hebdomadis and australia in China]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 2000; 21:91-3. [PMID: 11860762] [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 In order to confirm whether cattle serve the source of infection for patients with Leptospira interrogans serovar hebdomadis and australia. METHODS 12 field strains of leptospira interrogans serovar hebdomadis and australia were isolated from blood samples of patients with leptospirosis and farm cattle urine. An analysis of chromosome DNA restriction endonuclease patterns (REP) and restriction fragments length polymorphism (RFLP) of 16S + 23S rRNA gene were processed by digestion of chromosome DNA using EcoR I. RESULTS The same serovar field strains of Leptospira interrogans from blood samples of patients with leptospirosis and farm cattle urine resulted in unique restriction endonuclease patterns (REP) and ribosomal types (RT). The chromosome DNAs from field strains that belonged to different serovars of Leptospira interrogans caused different restriction endonuclease patterns and ribosomal types. CONCLUSION In accordance with this results, we recognize that farm cattle serve the infectious source of leptospirosis serovar hebdomadis and australia thus may have realistic significance in the control of leptospirosis serovar epidemic of hebdomadis and australia in China.
Collapse
|
193
|
Nie Y, Nakashima M, Brubaker PL, Li QL, Perfetti R, Jansen E, Zambre Y, Pipeleers D, Friedman TC. Regulation of pancreatic PC1 and PC2 associated with increased glucagon-like peptide 1 in diabetic rats. J Clin Invest 2000; 105:955-65. [PMID: 10749575 PMCID: PMC377475 DOI: 10.1172/jci7456] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The pancreatic processing enzymes, PC1 and PC2, convert proinsulin to insulin and convert proglucagon to glucagon and glucagon-like peptide 1 (GLP-1). We examined the effect of streptozotocin (STZ) treatment on the regulation of these enzymes and the production of insulin, glucagon, and GLP-1 in the rat. Pancreatic PC1 and PC2 mRNA increased >2-fold and >4-fold, respectively, in rats receiving intraperitoneal STZ (50 mg/kg) daily for 5 days. Immunocytochemistry revealed that, although pancreatic islet cells in the STZ-treated rats were sparse and atrophic PC1, PC2, glucagon, and GLP-1 immunoreactivity increased dramatically in the remaining islet cells. Heightened PC1 and PC2 expression was seen in cells expressing glucagon but not in insulin-expressing cells. Furthermore, in STZ-treated rats, bioactive GLP-1(7-36 amide) accumulated in pancreatic extracts and serum 3- and 2.5-fold, respectively, over control animals. This treatment also caused a 2-fold increase in the ratio of amidated forms of GLP-1 immunoreactivity to total glucagon immunoreactivity in the pancreas but did not affect the ratio of proinsulin to insulin. We conclude that hyperglycemic rats have an increased expression of prohormone converting enzymes in islet alpha cells, leading to an increase in amidated GLP-1, which can then exert an insulinotropic effect on the remaining beta cells.
Collapse
|
194
|
Li Y, Sha W, Nie Y, Wu H, She Q, Dai S, Jia L, Yu W. Effect of intragastric pH on control of peptic ulcer bleeding. J Gastroenterol Hepatol 2000; 15:148-54. [PMID: 10735538 DOI: 10.1046/j.1440-1746.2000.02055.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND We have performed series studies to investigate the effect of intragastric pH on control of peptic ulcer bleeding. In laboratory and animal studies, both platelet aggregation and gastric mucosal bleeding time were shown to be extremely sensitive to different pH levels. Platelet aggregation decreased significantly at pH > or = 6.8 and gastric mucosal bleeding time fell significantly at pH > or = 6.4. In a prospective clinical trial, primed infusions of different dosages of omeprazole (8 or 4 mg/h) after a bolus (40 mg) produced consistently high intragastric pH values in patients with bleeding duodenal ulcer. These results were not significantly different from that obtained from omeprazole 40 mg bolus treatment every 12 h (P > 0.05). However, primed injection with cimetidine (800 mg/12 h) was less effective (P < 0.05). METHODS In a retrospective analysis, 303 patients with bleeding peptic ulcer who were treated with cimetidine and 326 patients who were treated with omeprazole were compared. RESULTS The emergency surgery (4.91%) and mortality rates (1.84%) in the omeprazole group were not significantly different (P > 0.05) from those (7.28 and 1.99%) in the cimetidine group. However, the standardized emergency surgery rate of the omeprazole group (3.28%) was significantly lower than that (9.28%) of the cimetidine group (P < 0.05). CONCLUSION We conclude that increased intragastric pH to at least 6.4 with omeprazole is helpful in controlling peptic ulcer bleeding. Chinese patients require a lower dose of omeprazole than their Western counterparts to control ulcer bleeding.
Collapse
|
195
|
Nie Y, Li HH, Bula CM, Liu X. Stimulation of p53 DNA binding by c-Abl requires the p53 C terminus and tetramerization. Mol Cell Biol 2000; 20:741-8. [PMID: 10629029 PMCID: PMC85189 DOI: 10.1128/mcb.20.3.741-748.2000] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The carboxyl terminus of p53 is a target of a variety of signals for regulation of p53 DNA binding. Growth suppressor c-Abl interacts with p53 in response to DNA damage and overexpression of c-Abl leads to G(1) growth arrest in a p53-dependent manner. Here, we show that c-Abl binds directly to the carboxyl-terminal regulatory domain of p53 and that this interaction requires tetramerization of p53. Importantly, we demonstrate that c-Abl stimulates the DNA-binding activity of wild-type p53 but not of a carboxyl-terminally truncated p53 (p53Delta363C). A deletion mutant of c-Abl that does not bind to p53 is also incapable of activating p53 DNA binding. These data suggest that the binding to the p53 carboxyl terminus is necessary for c-Abl stimulation. To investigate the mechanism for this activation, we have also shown that c-Abl stabilizes the p53-DNA complex. These results led us to hypothesize that the interaction of c-Abl with the C terminus of p53 may stabilize the p53 tetrameric conformation, resulting in a more stable p53-DNA complex. Interestingly, the stimulation of p53 DNA-binding by c-Abl does not require its tyrosine kinase activity, indicating a kinase-independent function for c-Abl. Together, these results suggest a detailed mechanism by which c-Abl activates p53 DNA-binding via the carboxyl-terminal regulatory domain and tetramerization.
Collapse
|
196
|
Wu H, Nie Y, Huse WD, Watkins JD. Humanization of a murine monoclonal antibody by simultaneous optimization of framework and CDR residues. J Mol Biol 1999; 294:151-62. [PMID: 10556035 DOI: 10.1006/jmbi.1999.3141] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Optimal protein function often depends on co-operative interactions between amino acid residues distant in the protein primary sequence yet spatially near one another following protein folding. For example, antibody affinity is influenced by interactions of framework residues with complementarity-determining region (CDR) residues. However, despite the abundance of antibody structural information and computational tools the humanization of rodent antibodies for clinical use often results in a significant loss of affinity. To date, antibody engineering efforts have focused either on optimizing CDR residues involved in antigen binding or on optimizing antibody framework residues that serve critical roles in preserving the conformation of CDRs. In the present study a new approach which permits the rapid identification of co-operatively interacting framework and CDR residues was used to simultaneously humanize and optimize a murine antibody directed against CD40. Specifically, a combinatorial library that examined eight potentially important framework positions concomitantly with focused CDR libraries consisting of variants containing random single amino acid mutations in the third CDR of the heavy and light chains was expressed. Multiple anti-CD40 Fab variants containing as few as one murine framework residue and displaying up to approximately 500-fold higher affinity than the initial chimeric Fab were identified. The higher affinity humanized variants demonstrated a co-operative interaction between light chain framework residue Y49 and heavy chain CDR3 residue R/K101 (coupling energy, DeltaGI=0.9 kcal/mol). Screening of combinatorial framework-CDR libraries permits identification of monoclonal antibodies (mAb) with structures optimized for function, including instances in which the antigen induces conformational changes in the mAb. Moreover, the enhanced humanized variants contain fewer murine framework residues and could not be identified by sequential in vitro humanization and affinity muturation strategies. This approach to identifying co-operatively interacting residues is not restricted to antibody-antigen interactions and consequently, may be used broadly to gain insight into protein structure-function relationships, including proteins that serve as catalysts.
Collapse
|
197
|
Xing EP, Nie Y, Song Y, Yang GY, Cai YC, Wang LD, Yang CS. Mechanisms of inactivation of p14ARF, p15INK4b, and p16INK4a genes in human esophageal squamous cell carcinoma. Clin Cancer Res 1999; 5:2704-13. [PMID: 10537333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The 9p21 gene cluster, harboring growth suppressive genes p14ARF, p15INK4b, and p16INK4a, is one of the major aberration hotspots in human cancers. It was shown that p14ARF and p16INK4a play active roles in the p53 and Rb tumor suppressive pathways, respectively, and p15INK4b is a mediator of the extracellular growth inhibition signals. To elucidate specific targets and aberrations affecting this subchromosomal region, we constructed a detailed alteration map of the 9p21 gene cluster by analyzing homozygous deletion, hypermethylation, and mutation of the p14ARF, p15INK4b, and p16INK4a genes individually in 40 esophageal squamous cell carcinomas (ESCCs) and compared the genetic alterations with mRNA expression in 18 of these samples. We detected aberrant promoter methylation of the p16INK4a gene in 16 (40%), of p14ARF in 6 (15%), and of p15INK4b in 5 (12.5%) tumor samples. Most p16INK4a methylations were exclusive, whereas all but one of the p14ARF/p15INK4b methylations were accompanied by concomitant p16INK4a methylation. We detected homozygous deletion of p16INK4a in 7 (17.5%), of p14ARF-E1beta in 13 (33%), and of p15INK4b in 16 (40%) tumor samples. Most deletions occurred exclusively on the E1beta-p15INK4b loci. Two samples contained p14ARF deletion but with p16INK4a and p15INK4b intact. No mutation was detected in the p14ARF and p16INK4a genes. Comparative RT-PCR showed good concordance between suppressed mRNA expression and genetic alteration for p15INK4b and p16INK4a genes in the 18 frozen samples, whereas 5 of the 13 cases with suppressed p14ARF mRNA expression contained no detectable E1beta alteration but aberrations in the p16INK4a locus. Our results show that in human ESCCs, p14ARF is a primary target of homozygous deletion along with p15INK4b, whereas p16INK4a is the hotspot of hypermethylation of the 9p21 gene cluster. The frequent inactivation of the p14ARF and p16INK4a genes may be an important mechanism for the dysfunction of both the Rb and p53 growth regulation pathways during ESCC development.
Collapse
|
198
|
Nie Y, Hu CH, Sun J, Jin RS, Zheng PJ. An exo-polyhedral bicyclic 11-vertex closo-ruthenaborane: [(PPh 3)(CH 3COS) 2RuB 10H 8]. Acta Crystallogr C 1999. [DOI: 10.1107/s010827019900462x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
199
|
Nie Y, Li Y, Wu H, Sha W, Du H, Dai S, Wang H, Li Q. Colloidal bismuth pectin: an alternative to bismuth subcitrate for the treatment of Helicobacter pylori--positive duodenal ulcer. Helicobacter 1999; 4:128-34. [PMID: 10382127 DOI: 10.1046/j.1523-5378.1999.98281.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND Bismuth triple therapy provides consistently good results in Helicobacter pylori eradication worldwide, whereas quadruple therapy using a combination of omeprazole and bismuth triple regimen has produced cure rates in excess of 90%. The prevalence of metronidazole-resistant strains was 26.8% in our area. Colloidal bismuth pectin (CBP) is a new, lower-priced bismuth salt made in China. The purpose of this study was to investigate the efficacy and safety of CBP triple and quadruple regimens in the treatment of H. pylori-positive duodenal ulcer. MATERIALS AND METHODS In this prospective trial, 205 patients with H. pylori-positive duodenal ulcer were allocated randomly to receive one of four regimens: metronidazole, 200 mg; amoxicillin, 250 mg; and colloidal bismuth subcitrate (CBS), 120 mg (group 1), or CBP, 100 mg qid (group 2) for 2 weeks, then continued CBS, 240 mg, or CBP, 200 mg bid for a further 2 weeks. A quadruple regimen using a combination of omeprazole, 20 mg bid, and CBS triple therapy (group 3) or CBP triple therapy (group 4), respectively, was given to patients for 1 week, followed by omeprazole, 20 mg once daily for a further 3 weeks. Further endoscopy was performed at least 4 weeks after cessation of the treatment. H. pylori status was determined by histology, a 14C urea breath test, and a urease test. RESULTS The per-protocol H. pylori cure rates were 85% (22 of 26 patients), 90% (35 of 39), 96% (46 of 48), and 95% (75 of 79) for groups 1 through 4. In the intention-to-treat analysis, cure rates were 79% (22 of 28), 83% (35 of 42), 90% (46 of 51), and 89% (75 of 84), respectively. The cure rates of quadruple therapy were higher than those of triple therapy; an 8.2% difference was not statistically significant (95% confidence interval [CI], 2.3-18.7%). The ulcer-healing rates were 88%, 87%, 98%, and 97%, respectively, for groups 1 through 4. The ulcer pain was relieved more rapidly in quadruple- than in triple-therapy regimens. Two patients discontinued treatment prematurely owing to drug-related side effects. CONCLUSION One-week quadruple therapy is highly effective and safe in H. pylori eradication in Chinese patients. CBP is as effective as CBS.
Collapse
|
200
|
Feng X, Qin J, Liang Z, Shi M, Wang Y, Nie Y. [Analysis of rRNA gene restriction fragments length polymorphism of Leptospira in China]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1999; 39:241-6. [PMID: 12555541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Sixty-four Leptospira international and domestic reference strains, which belonging to fifty-four serovars, and twenty-seven field strains were examined by using EcoR I restriction endonuclease analysis of genomic DNA and restriction fragments length polymorphism of rRNA gene, fifty-six Leptospiral ribotypes(RTs) were described. Most serovars gave specific patterns. Serovars in the same serogroup possess common core-segments, but we found RTs of reference strains from China and other countries are different. Most field strains have RTs with correspond of reference strains, only a few bands were shown different if RTs were different. A notable result was that the field strains of serovar pomona have the same Rt as the international reference strain but different from the domestic reference strain.
Collapse
|