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Zhu T, Wu R, Hang J, Lin X, Sun Y. Toward Human-Like Grasp: Functional Grasp by Dexterous Robotic Hand Via Object-Hand Semantic Representation. IEEE Trans Pattern Anal Mach Intell 2023; 45:12521-12534. [PMID: 37134035 DOI: 10.1109/tpami.2023.3272571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Intelligent robotic manipulation is a challenging study of machine intelligence. Although many dexterous robotic hands have been designed to assist or replace human hands in executing various tasks, how to teach them to perform dexterous operations like human hands is still a challenge. This motivates us to conduct an in-depth analysis of human behavior in manipulating objects and propose an object-hand manipulation representation. This representation provides an intuitive and clear semantic indication of how the dexterous hand should touch and manipulate an object based on the object's own functional areas. At the same time, we propose a functional grasp synthesis framework, which does not require real grasp label supervision, but relies on the guidance of our object-hand manipulation representation. In addition, in order to obtain better functional grasp synthesis results, we propose a network pre-training method that can make full use of easily obtained stable grasp data, and a network training strategy to coordinate the loss functions. We conduct object manipulation experiments on a real robot platform, and evaluate the performance and generalization of our object-hand manipulation representation and grasp synthesis framework.
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Wu R, Zhu T, Peng W, Hang J, Sun Y. Functional Grasp Transfer Across a Category of Objects From Only one Labeled Instance. IEEE Robot Autom Lett 2023. [DOI: 10.1109/lra.2023.3260725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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Zhang Y, Hang J, Zhu T, Lin X, Wu R, Peng W, Tian D, Sun Y. FunctionalGrasp: Learning Functional Grasp for Robots Via Semantic Hand-Object Representation. IEEE Robot Autom Lett 2023. [DOI: 10.1109/lra.2023.3264760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Affiliation(s)
- Yibiao Zhang
- School of Information and Communication Engineering, Dalian University of Technology, Dalian, China
| | - Jinglue Hang
- School of Information and Communication Engineering, Dalian University of Technology, Dalian, China
| | - Tianqiang Zhu
- School of Information and Communication Engineering, Dalian University of Technology, Dalian, China
| | - Xiangbo Lin
- School of Information and Communication Engineering, Dalian University of Technology, Dalian, China
| | - Rina Wu
- School of Information and Communication Engineering, Dalian University of Technology, Dalian, China
| | - Wanli Peng
- School of Information and Communication Engineering, Dalian University of Technology, Dalian, China
| | - Dongying Tian
- School of Information and Communication Engineering, Dalian University of Technology, Dalian, China
| | - Yi Sun
- School of Information and Communication Engineering, Dalian University of Technology, Dalian, China
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Zhang Y, Xiang J, Han Y, Huang M, Hang J, Abbas AE, Li H. Initial experience of robot-assisted Ivor-Lewis esophagectomy: 61 consecutive cases from a single Chinese institution. Dis Esophagus 2018; 31:5032891. [PMID: 29873693 DOI: 10.1093/dote/doy048] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This study aims to report the technical details and preliminary outcomes of robot-assisted Ivor-Lewis esophagectomy (RAILE) using two different types of intrathoracic anastomosis from a single institution in China. From May 2015 to October 2017, 61 patients diagnosed with mid-lower esophageal cancer were treated with RAILE. The RAILE procedure was performed in two stages. The first 35 patients underwent circular end-to-end stapled intrathoracic anastomosis (stapled group), and the remaining 26 patients had a double-layered, completely hand-sewn intrathoracic anastomosis (hand-sewn group). Patient characteristics, surgical techniques, postoperative complications, and pathology outcomes were analyzed. The mean operating time and mean blood loss were 315.6 ± 59.4 minutes and 189.3 ± 95.8 mL, respectively. There was one patient who underwent conversion to thoracotomy. The 30-day and in-hospital mortality rates were 0%. Overall complications were observed in 22 patients (36.1%) according to the Clavien-Dindo (CD) and the Esophagectomy Complications Consensus Group (ECCG) classifications, of whom 6 patients (9.8%) had anastomotic leakage (ECCG, Type II). The median length of hospitalization (LOH) was 10 days (IQR, 5 days). Complete (R0) resection was achieved in all cases. The mean tumor size was 3.2 ± 1.5 cm, and the mean number of totally dissected lymph nodes was 19.3 ± 9.2. Regarding the operative outcomes between stapled and hand-sewn groups, there were no significant differences in the operative time (325.4 ± 66.6 vs. 302.3 ± 45.9 min, P = 0.114), blood loss (172.9 ± 74.1 vs. 211.5 ± 117.0 mL, P = 0.147), conversion rate (2.9 vs. 0%, P = 1.000), overall complication rate (37.1 vs. 34.6%, P = 0.839) or LOH (10 vs. 9.5 days, P = 0.415). RAILE using both stapled and hand-sewn intrathoracic anastomosis is safe and technically feasible with satisfactory perioperative outcomes for the treatment of mid-lower thoracic esophageal cancer.
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Affiliation(s)
- Y Zhang
- Department of Thoracic Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - J Xiang
- Department of Thoracic Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Y Han
- Department of Thoracic Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - M Huang
- Department of Epidemiology, MD Anderson Cancer Center, University of Texas, Houston, Texas
| | - J Hang
- Department of Thoracic Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - A E Abbas
- Department of Thoracic Medicine and Surgery, Temple University Health System, Lewis Katz School of Medicine, Philadelphia, Pennsylvania, USA
| | - H Li
- Department of Thoracic Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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Xiao YZ, Chen Q, Hang J, Shi YY, Xiao YZ, Wu J, Hong YZ, Wang YP. Selective induction, purification and characterization of a laccase isozyme from the basidiomyceteTrametessp. AH28-2. Mycologia 2017. [DOI: 10.1080/15572536.2005.11832993] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | | | | | - Y. Y. Shi
- Laboratory of Structure Biology, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, P.R. of China
| | | | | | | | - Y. P. Wang
- Laboratory of Microorganism and Gene Technology, School of Life Sciences, Anhui University, Hefei, Anhui, 230039, P.R. of China
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Xiang J, Zang W, Che J, Chen K, Hang J. Regulation network analysis in the esophageal squamous cell carcinoma. Eur Rev Med Pharmacol Sci 2012; 16:2051-2056. [PMID: 23280018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND The incidence of esophageal squamous cell carcinoma (ESCC) has high regional selectivity. The molecular mechanisms of ESCC are complex and involve multiple oncogenes, tumor suppressor genes, receptor tyrosine kinases, cytoplasmic enzymes, and tumor interstitial elements. AIM Here we used bioinformatics to obtain some important genes and pathways involved in ESCC. MATERIALS AND METHODS In this article, we did Affymetrix microarray data collection from three big databases, and then selected all the differentially expressed genes (DEGs) according to some principles. On this basis, we carried out regulation network analysis and pathway enrichment analysis, obtaining ESCC related regulation network analysis, after which we selected significant pathways on regulation network and established TF-pathway regulation network. RESULTS In the transcription factors (TFs) regulation network we found SP1, E2F1, USF2 and SP3 form a local network which suggested that these TFs might play a more important role in ESCC. Some key pathways were also identified, such as P53 signaling pathway, melanoma and prostate cancer pathways. CONCLUSIONS The identification of crucial molecular pathways involved in ESCC would ultimately improve therapeutic effects and facilitate the development of new treatment strategies.
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Affiliation(s)
- J Xiang
- Department of Thoracic Surgery, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Xu W, Hang J, Gao W, Zhao Y, Guo L. Job stress associated with blood pressure among Chinese workers: results from Shiso study. Heart 2011. [DOI: 10.1136/heartjnl-2011-300867.299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Li BZ, Lei W, Zhang CY, Zhou F, Li N, Shi SS, Feng XL, Chen ZL, Hang J, Qiu B, Wan JT, Shao K, Xing XZ, Tan XG, Wang Z, Xiong MH, He J. Increased expression of paxillin is found in human oesophageal squamous cell carcinoma: a tissue microarray study. J Int Med Res 2008; 36:273-8. [PMID: 18380937 DOI: 10.1177/147323000803600209] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Oesophageal cancer is one of the most common cancers worldwide. Currently, the tumour, node, metastasis (TNM) staging system is the primary method for determining its extent and prognosis, however, data suggest this system does not predict prognosis accurately. Research has, therefore, concentrated on searching for specific biomarkers. Paxillin has been shown to play an important role in controlling cell spread and migration. Its over-expression is considered to correlate with the prognosis of some types of cancers, however, the relationship between paxillin expression and clinical outcome in oesophageal cancer has not been investigated. This study determined the expression of paxillin by immunohistochemistry on the tissue microarray of 100 oesophageal squamous cell cancer patients followed up for a mean of 55 months. Paxillin was over-expressed in tumours in 27/100 cases, compared with 6/100 cases for adjacent non-tumoural cells. No correlation occurred between expression of paxillin and overall patient survival, hence paxillin is not an effective prognostic marker in these patients.
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Affiliation(s)
- B-Z Li
- Department of Thoracic Surgery, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
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Xiao YZ, Hong YZ, Li JF, Hang J, Tong PG, Fang W, Zhou CZ. Cloning of novel laccase isozyme genes from Trametes sp. AH28-2 and analyses of their differential expression. Appl Microbiol Biotechnol 2006; 71:493-501. [PMID: 16283298 DOI: 10.1007/s00253-005-0188-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Revised: 09/06/2005] [Accepted: 09/07/2005] [Indexed: 10/25/2022]
Abstract
Three novel laccase isozyme genes, lacA, lacB, and lacC, have been identified from basidiomycete Trametes sp. AH28-2. These genes display a high similarity with other basidiomycete laccases at the amino acid level. An inferred TATA box and several putative CAAT, MRE, XRE, and CreA consensus sequences were identified in the lacA, lacB, and lacC promoter regions. Different from the TATA boxes of lacA and lacB at about -100, the TATA box of lacC is located at -172. For all the isozymes, copper ion is essential for laccase synthesis in Trametes sp. AH28-2. More interestingly, different aromatic compounds can selectively induce the production of distinct laccase isozymes, with o-toluidine inducing the expression of laccase A (LacA) while 3,5-dihydroxytoluene mainly stimulating the production of laccase B (LacB). Quantitative reverse transcriptase-polymerase chain reaction showed that the accumulation of laccase messenger RNA transcripts is accompanied by the increase of corresponding enzyme activity in cultures. The glucose-repression effect on laccase expression in Trametes sp. AH28-2 was also observed. Furthermore, lower Cu2+ concentration (lower than 0.5 mM) can induce LacA and a novel laccase (LacC), and the latter will disappear when Cu2+ concentration is increased up to 1-2 mM. Upon induction by 3,5-dihydroxytoluene, the ratio of LacA to LacB decreased in the later phase of induction.
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Affiliation(s)
- Y Z Xiao
- School of Life Science & Modern Experiment Center, Anhui University, 230039, Hefei, People's Republic of China.
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He J, Zhang C, Hang J, Shao K. P-045 Decreased expression and novel mutation of HYAL1 in patients with non-small cell lung cancer. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80539-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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11
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Xiao YZ, Chen Q, Hang J, Shi YY, Wu J, Hong YZ, Wang YP. Selective Induction, Purification and Characterization of a Laccase Isozyme from the Basidiomycete Trametes sp. AH28-2. Mycologia 2004. [DOI: 10.2307/3761984] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Xiao YZ, Chen Q, Hang J, Shi YY, Xiao YZ, Wu J, Hong YZ, Wang YP. Selective induction, purification and characterization of a laccase isozyme from the basidiomycete Trametes sp. AH28-2. Mycologia 2004; 96:26-35. [PMID: 21148825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The white-rot fungus Trametes sp. AH28-2 can synthesize extracellular laccase by induction in cellobiose-based liquid culture medium. Both yields and composition of laccase isozymes, produced by Trametes sp. AH28-2, would be quite different with induction by different small-molecule aromatic compounds, o-toluidine, guaiacol and 3,5-dihydroxytoluene, which affected microbial growth and the synthesis of laccase isozymes differentially. Higher concentrations of the three inducers could considerably increase laccase isozymes yields but not change the laccase composition. Coculturing of Trametes sp. AH28-2 with either Aspergillus oryzae or Gloeophyllum trabeum showed a few effects on laccase production. Laccase isozyme, laccase B, was selectively induced by 3,5-dihydroxytoluene and purified to homogeneity by two-step chromatography. Purified laccase B appeared as blue, with a broad peak at about 600 nm and a shoulder peak at about 330 nm. The ratio of absorbance at 280 nm to that at 600 nm was 21. Every molecule of laccase B had approximately four copper atoms. Molecular mass of laccase B was estimated to be 74 kDa on SDS-PAGE, 72 kDa by FPLC and was determined to be 71 454 Da by mass spectrum. After being treated with N-glycosidase F, laccase B lost 25% of its molecular mass. The isoelectric point of laccase B was 4.0. Its optimal pH and temperature for oxidizing guaiacol were respectively 4.7 and 45 C. The half-life of the enzyme at 60 C was 14.0 min. The enzyme showed a good stability in a range of pH value of 3.5-7.5. The K(m) values of the enzyme toward substrates syringaldazine, guaiacol, ABTS, and DMOP were respectively 28.0, 1249.0, 177.0 and 109.8 μM. The corresponding V(max) are 504.0, 1910.0, 117.4 and 159.0 μM min(-1) mg(-1). In addition, activity of laccase B was inhibited strongly by sodium azide and cyanide, mildly by SDS and trifluoroacetic acid, but only weakly by dimethyl sulfoxide.
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Affiliation(s)
- Y Z Xiao
- Laboratory of Structure Biology, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, P.R. of China
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Wang H, Hang J, Shi Z, Li M, Yu D, Kandimalla E, Agrawal S, Zhang R. Antisense oligonucleotide targeted to RIα subunit of cAMP-dependent protein kinase (GEM231) enhances therapeutic effectiveness of cancer chemotherapeutic agent irinotecan in nude mice bearing human cancer xenografts: in vivo synergistic activity, pharmacokinetics and host toxicity. Int J Oncol 2002. [DOI: 10.3892/ijo.21.1.73] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Hang J, Tian SK, Tang L, Deng L. Asymmetric synthesis of alpha-amino acids via cinchona alkaloid-catalyzed kinetic resolution of urethane-protected alpha-amino acid N-carboxyanhydrides. J Am Chem Soc 2001; 123:12696-7. [PMID: 11741442 DOI: 10.1021/ja011936q] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J Hang
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, USA
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Gong HC, Hang J, Kohler W, Li L, Su TZ. Tissue-specific expression and gabapentin-binding properties of calcium channel alpha2delta subunit subtypes. J Membr Biol 2001; 184:35-43. [PMID: 11687876 DOI: 10.1007/s00232-001-0072-7] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2001] [Indexed: 10/28/2022]
Abstract
We report here the tissue-specific expression and gabapentin-binding properties of calcium channel alpha2delta subunits. Northern blot analysis demonstrated that human alpha2delta-1, -2, and -3 mRNA all had high levels of expression in brain, heart and skeletal muscle. However, the highest expression of human alpha2delta-2 mRNA was found in lung. Human alpha2delta-1, -2, and -3 mRNAs were detected in all portions of brain tested. Western blotting revealed that alpha2delta-2 protein was predominantly expressed in cerebellar cortex (brain) and undetectable in lung. The dissociation between mRNA and protein levels of human alpha2delta-2 in lung suggests possible post-transcriptional regulation. Although mouse alpha2delta-1 proteins exhibited a similar tissue distribution profile as that of human, tissue distribution of mouse alpha2delta-2 and -3 mRNA revealed a different profile. Mouse alpha2delta-3 mRNA was restricted to brain and mouse alpha2delta-2 mRNA was not detectable in lung. Gel electrophoresis under a reduced condition resulted in a mobility shift of both alpha2delta-1 and alpha2delta-2 proteins, suggesting that alpha2 and delta of alpha2delta-2 protein are linked by disulfide bond as are alpha2 and delta of alpha2delta-1. Scatchard plots revealed a single population of gabapentin binding sites for human alpha2delta-2 with the KD value twofold higher than that of porcine alpha2delta-1 (156 +/- 25 nm vs. 72 +/- 9 nm). Inhibition of gabapentin binding to alpha2delta-2 by selected amino acids and gabapentin analogs produced a binding profile similar, but not identical to that of alpha2delta-1.
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Affiliation(s)
- H C Gong
- Department of Molecular Sciences, Pfizer Global Research and Development, Ann Arbor, MI 48105, USA
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Xiao YZ, Zhang M, Wu J, Wang YP, Hang J, Zeng WY, Shi YY. [Factors of laccase producing and fermentation conditions by a new white-rot fungus AH28-2]. Sheng Wu Gong Cheng Xue Bao 2001; 17:579-83. [PMID: 11797226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
White-rot fungus AH28-2, a newly isolated strain, produced effectively laccase by induction when grown on a synthetic medium. Aromatic compounds of low molecular weight had an inducing influence on laccase production and its isoenzyme compositions. The using of o-toluidine or syringic acid had the best inducing effect. Cu2+ concentration in medium had distinguished effect on laccase production. Enzyme activity was notably increased by Cu2+ and reached the maximum when Cu2+ final concentration was 5 mumol/L. Mn2+ inhibited the synthesis of laccase. Carbon and nitrogen limitation were not beneficial to laccase synthesis, while high nutrient organic medium was beneficial to the growth of cell and the synthesis of laccase. Using cellobiose as the sole carbon source, the highest level enzyme activity reached 82,923. 7 u/L under the condition of optimum fermentation with ABTS as substrate. This enzyme activity was 2.9-fold higher compared to the reported data on international references in recent years.
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Affiliation(s)
- Y Z Xiao
- School of Life Sciences, Anhui University, Hefei 230039, China.
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Lazarev VV, Roth RA, Kazakevich Y, Hang J. Detection of premalignant oral lesions in hamsters with an endoscopic fluorescence imaging system. Int J Oral Maxillofac Surg 2000. [DOI: 10.1034/j.1399-0020.2000.290519-3.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Hang J, Shi H, Li D, Liao Y, Lian D, Xiao Y, Xue H. Ligand binding and structural properties of segments of GABAA receptor alpha 1 subunit overexpressed in Escherichia coli. J Biol Chem 2000; 275:18818-23. [PMID: 10764739 DOI: 10.1074/jbc.m000193200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The gamma-aminobutyric acid, type A (GABA(A)), receptor is the target for numerous therapeutic compounds. In the present study, the Gln(28)-Leu(296), Gln(28)-Arg(276), Gln(28)-Arg(248), and Gln(28)-Glu(165) (numbering of bovine precursor protein) segments of its alpha(1) subunit were overexpressed in Escherichia coli, along with Cys(166)-Leu(296) produced previously, for structural analysis by circular dichroism and ligand binding studies by fluorescence spectroscopy. Results showed that the protein segments were rich in beta-sheet structures. Binding of the fluorescent benzodiazepine Bodipy-FL Ro-1986 was evident from fluorescence resonance energy transfer and fluorescence anisotropy measurements. The binding affinity was in the micromolar range. The binding was attributable more to Cys(166)-Leu(296) than to Gln(28)-Glu(165) and was inhibited by known central benzodiazepine site ligands. Three point mutations, Y187A, T234A, and Y237A, were found to perturb protein secondary structures. Studies with the single Trp mutants W198Y and W273Y indicated that Trp(273) was closer to the binding site than Trp(198).
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Affiliation(s)
- J Hang
- Department of Biochemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
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Cai S, Liu X, Hang J. [Community characteristics of rare trees at Dalaoling of Three-Gorge reservoir area in western Hubei Province]. Ying Yong Sheng Tai Xue Bao 2000; 11:165-8. [PMID: 11767585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The quantitative characteristics, plant frequency in layers and species diversity of David involucrata var. vilnoriniara, Euptlea pleiosperma, Stewartia sinensis and Pterostyrax psilophtila communities at Dalaoling National Forest Park Reserve of Yichang were studied qualitatively and quantitatively. The community composition and structure were made clear, the succession courses and stages of the communities were revealed, and the role of these rare trees on the succession course of communities and the cause of being in imminent danger were analyzed, which provided a theoretical basis for protecting the rare trees in the Three-Gorge reservoir area.
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Affiliation(s)
- S Cai
- Hubei Forestry Academy, Wuhan 430075
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Yan X, Xue H, Liu H, Hang J, Wong JT, Zhu G. NMR studies of Bacillus subtilis tRNA(Trp) hyperexpressed in Escherichia coli. Assignment of imino proton signals and determination of thermal stability. J Biol Chem 2000; 275:6712-6. [PMID: 10702225 DOI: 10.1074/jbc.275.10.6712] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
15N-Labeled Bacillus subtilis tRNA(Trp) wild type and a series of mutants were hyperexpressed in Escherichia coli and purified for NMR studies with the use of two-dimensional nuclear Overhauser effect spectroscopy (NOESY) and heteronuclear single quantum correlation (HSQC) and three-dimensional NOESY-HSQC techniques. These made possible chemical shift assignments of imino protons and determination of the thermal stability of the tRNA(Trp) molecules. Almost all of the imino protons in the helical regions and the tertiary base pairs were assigned, except three imino protons of the AU base pairs whose peaks were not clearly observed. Several base triplets found in the crystal structure of tRNA were observed in the present study as well. These studies also revealed two components of tRNA(Trp), which could not be separated by high pressure liquid chromatography, corresponding to s(4)U and U at position 8 of the tRNA(Trp), as indicated by two different sets of peaks for the TpsiC and D arms. The modification at position 8 altered the local conformation of the core region of the tRNA. Thermal unfolding experiments showed that the unfolding process is cooperative in the presence of a high concentration of magnesium ions and that the component corresponding to the s(4)U8 is more stable than the U8 component, thus providing evidence that the thiolation of U8 stabilizes the tertiary structure of tRNA.
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Affiliation(s)
- X Yan
- Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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Zhu GP, Xu C, Teng MK, Tao LM, Zhu XY, Wu CJ, Hang J, Niu LW, Wang YZ. Increasing the thermostability of D-xylose isomerase by introduction of a proline into the turn of a random coil. Protein Eng 1999; 12:635-8. [PMID: 10469823 DOI: 10.1093/protein/12.8.635] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Thermostability can be increased by introducing prolines at suitable sites in target proteins. Two single (G138P, G247D) mutants and one double (G138P/G247D) mutant of xylose isomerase from Streptomyces diastaticus No.7, strain M1033 have been constructed by site-directed mutagenesis. With respect to the wild-type enzyme, G138P showed about a 100% increase in thermostability, and G247D showed an increased catalytic activity. Significantly, the double mutant, G138P/G247D displayed even higher activity than G247D and better heat stability than G138P. Its half life was about 2.5-fold greater than the wild-type enzyme, using xylose as a substrate. Molecular modelling suggested that the introduction of a proline residue in the turn of a random coil may cause the surrounding conformation to be tightened by reducing the backbone flexibility. The change in thermostability can, therefore, be explained based on changes in the molecular rigidity. Furthermore, the improvements in the properties of the double mutant indicated that the advantages of two single mutants can be combined effectively.
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Affiliation(s)
- G P Zhu
- Department of Molecular Biology and Cell Biology and The Key Lab of Structural Biology, USTC, CAS, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, China
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22
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Abstract
BACKGROUND Various methods of detecting cancer with fluorescence have been developed. One type of fluorescence is based on the tumor-localizing properties of certain dyes. However, the phototoxicity of most known tumor-localizing dyes hinders the safe use of such diagnostic methods. The authors have developed a fluorescence imaging system to detect the distribution of a nontoxic dye, fluorescein, and they have evaluated the feasibility of the system by using it to detect oral dysplastic lesions in hamsters. METHODS Dysplasia was induced in the cheek pouches of hamsters by application of the carcinogen 9,10-dimethyl-1,2-benzantracene. Fluorescein was administered to the hamsters either intravenously or orally before the fluorescence examination. The endoscopic fluorescence system produced dye-distribution images of both treated and control pouches. Two fluorescence images in different spectral regions were processed for each dye image. Biopsy material from both pouches was examined histopathologically. RESULTS The accumulation of fluorescein was detected in 22 of 23 specimens containing dysplastic lesions. CONCLUSIONS These results demonstrate the utility of this fluorescein accumulation method in the detection of dysplasia. The accumulation of fluorescein in dysplastic lesions may point to acidification of interstitial medium in such lesions.
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Affiliation(s)
- V V Lazarev
- Laser Research Laboratory, Lahey Clinic Medical Center, Burlington, Massachusetts 01805, USA
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23
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Xue H, Hang J, Chu R, Xiao Y, Li H, Lee P, Zheng H. Delineation of a membrane-proximal beta-rich domain in the GABAA receptor by progressive deletions. J Mol Biol 1999; 285:55-61. [PMID: 9878387 DOI: 10.1006/jmbi.1998.2317] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The type A gamma-aminobutyric acid (GABAA) receptor plays a major inhibitory role in the central nervous system. Structural elucidation of the GABAA receptor has been impeded by the large size of the receptor. We present here the delineation of a minimal structural domain as the first step of dissecting the receptor structure. This was achieved through prediction-assisted progressive deletions: the prediction of a candidate structural domain rich in beta-strands with no close similarity to known structures was tested by deleting putative secondary structure elements from the ends of the proposed domain, as well as mutations within the terminal secondary structures. Such progressive deletions revealed the limits of an integral domain, spanning Cys180 to Met293 (numbering of human alpha1 subunit). Below these limits the intact domain structure, as indicated by its circular dichroism, collapses. Based on its putative position, this domain is provisionally designated the membrane-proximal beta-rich domain of GABAA receptor. The inclusion of sequences from the first two out of four previously suggested transmembrane segments and one of the two conserved Cys residues in this domain defines important constraints to the receptor structure.
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Affiliation(s)
- H Xue
- Department of Biochemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
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24
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Hang J, Rillema JA. Possible involvement of P13K in prolactin-stimulated milk product formation and iodide transport in mouse mammary explants. Proc Soc Exp Biol Med 1998; 219:154-9. [PMID: 9790174 DOI: 10.3181/00379727-219-44329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The in vitro effect of wortmannin, an inhibitor of P13 kinase, on prolactin (PRL) stimulated p70S6K, iodide transport, and milk product synthesis were investigated in cultured mouse mammary tissues. Mouse mammary gland explants were initially incubated for 24 hr in media M199 containing 1 microg/ml insulin and 10(-7)M cortisol. A subsequent treatment with wortmannin impeded, in a dose-dependent fashion, the PRL stimulation of casein, lipid, and lactose synthesis as well as the PRL stimulation of iodide transport. Rapamycin (25 ng/ml), an inhibitor of p70S6K, also inhibited the effect of PRL on iodide transport; this drug was earlier shown to inhibit PRL effects on milk product synthesis. These results suggest the possible involvement of p70S6K and P13-kinase in PRL-stimulated milk product formation and iodide transport in mouse mammary explants. Since wortmannin caused a diminished cellular content of p70S6K and a reduced extent of P70S6K migration in polyacrylamide gels (likely due to dephosphorylation), P13-kinase likely lies upstream in the PRL signaling pathway for p70S6K activation.
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Affiliation(s)
- J Hang
- Department of Physiology, School of Medicine, Wayne State University, Detroit, Michigan 48201, USA
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25
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Abstract
GABA(A) receptor plays a major role in inhibitory synaptic transmission in the central nervous system and is the target of drugs such as the benzodiazepine tranquilizers. The polymeric membrane protein nature of GABA(A) receptor has rendered structural elucidation of the receptor a formidable task, greatly hampering structure-based drug design. We report here the first expression in Escherichia coli of a fragment of GABA(A) receptor. This 131-residue fragment, spanning Cys166 to Leu296 of human GABAA receptor alpha1 subunit, contains residues previously suggested to be involved in benzodiazepine binding. The overexpressed non-fusion recombinant protein was purified to near homogeneity and characterized by circular dichroism (CD), which showed that the recombinant protein has well defined secondary structures where beta-strands are dominant. The stability of the secondary structures was demonstrated by CD spectra at high pH and elevated temperature. Excluding part of the sequences from the carboxyl terminal of the fragment resulted in dramatic changes in the secondary structures comparable to the effects caused by SDS denaturation. Our results therefore suggest that the 131-residue fragment harbors an integral structural domain of the receptor. The overexpression of the recombinant protein fragment thus opens the way to the biochemical and structural studies of a functionally important region of the receptor, and exemplifies an effective approach of expression and characterization that potentially may be extended to other members of the ligand gated channel receptor superfamily, to which the GABA(A) receptor belongs.
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Affiliation(s)
- H Xue
- Department of Biochemistry, Hong Kong University of Science and Technology, Clear Water Bay.
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26
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Hang J, Rillema JA. Effect of rapamycin on prolactin-stimulated S6 kinase activity and milk product formation in mouse mammary explants. Biochim Biophys Acta 1997; 1358:209-14. [PMID: 9332457 DOI: 10.1016/s0167-4889(97)00057-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The in vitro effects of rapamycin on prolactin (PRL)-stimulated S6 kinase activity and milk product synthesis were investigated in cultured mouse mammary tissues. Mouse mammary gland explants were initially incubated for 24 h in M199 media containing 1 microgram/ml insulin and 10(-7) M cortisol. A subsequent treatment of the tissues with 1 microgram/ml PRL for 12 h caused a 98% increase in S6 kinase activity in the cytosolic fraction; effects were not observed at earlier times. PRL at or above 500 ng/ml was needed to elicit a maximum stimulation of S6 kinase activity, and this response was specific for lactogenic hormones (PRL, hPL, hGH). Rapamycin, an inhibitor of 70 K S6 kinase, was employed to assess the possible physiological role of S6 kinase in the PRL stimulation of milk product formation. Rapamycin (25-100 ng/ml) impeded, in a dose-dependent fashion, the PRL stimulation of casein, lipid and lactose synthesis in concert with its inhibition of cytoplasmic S6 kinase activity. These results suggest a possible role for the activation of 70 K kinase in the signalling pathway for the PRL regulation of milk product synthesis in the mammary gland.
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Affiliation(s)
- J Hang
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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27
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Hang J, Rillema JA. Prolactin's effects on lipoprotein lipase (LPL) activity and on LPL mRNA levels in cultured mouse mammary gland explants. Proc Soc Exp Biol Med 1997; 214:161-6. [PMID: 9034134 DOI: 10.3181/00379727-214-44083] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The in vitro effects of prolactin (PRL) on lipoprotein lipase (LPL) activity and on LPL mRNA levels were studied in cultured mammary tissues derived from mid-pregnant mice. Mouse mammary gland tissues were initially incubated for 24 hr in M199 media containing 1 microg/ml insulin and 10(-7) M cortisol. A subsequent treatment of the tissues with 1 microg/ml PRL caused a 76% increase in heparin-releasable LPL (hrLPL) activity after 24 hr. A significant increase in LPL activity was detected 16 hr after PRL addition, but not at earlier times. PRL at 100 ng/ml elicited a maximum stimulation of LPL activity. When Northern hybridization techniques were employed, PRL was also found to increase the tissue content of LPL mRNA; this effect was initially detected after a 6-hr PRL treatment employing PRL concentrations of 50 ng/ml and above. Specificity studies revealed that only lactogenic hormones stimulated LPL activity and LPL mRNA accumulation in cultured mammary tissues. PRL also expressed a small (25% increase), but significant, effect on ATP citrate-lyase activity in mammary tissues cultured for more than 6 hr with the hormone.
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Affiliation(s)
- J Hang
- Department of Physiology, Wayne State University, Detroit, Michigan 48201, USA
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28
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Mathieu-Costello O, Agey PJ, Wu L, Hang J, Adair TH. Capillary-to-fiber surface ratio in rat fast-twitch hindlimb muscles after chronic electrical stimulation. J Appl Physiol (1985) 1996; 80:904-9. [PMID: 8964755 DOI: 10.1152/jappl.1996.80.3.904] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We examined the relative plasticity of capillaries and fiber mitochondria in rat fast-twitch hindlimb muscles in response to chronic electrical stimulation. Specifically we addressed whether the size of the capillary-fiber interface increases in proportion to fiber mitochondrial volume, inasmuch as fiber aerobic capacity increases severalfold with chronic stimulation. Tibialis anterior and extensor digitorum longus muscles of six rats [367 +/- 17 (SD) g body wt] were stimulated (10 Hz, 8 h/day, 7 days/wk) for 28 consecutive days. Subsequently they were perfusion fixed in situ and stimulated, and contralateral control samples from the midbelly were processed for electron microscopy and morphometry. Capillary length density, capillary-to-fiber ratio, and fiber mitochondrial volume density increased two- to threefold in stimulated muscles, with no change in fiber or capillary diameter. Capillary-to-fiber surface area ratio per fiber unit mitochondrial volume was unchanged in stimulated muscles compared with contralateral controls, indicating a proportional increase in the size of the capillary-fiber interface and fiber mitochondrial volume in the muscles after chronic electrical stimulation.
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Affiliation(s)
- O Mathieu-Costello
- Department of Medicine, University of California, San Diego, La Jolla 92093-0623, USA
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29
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Abstract
Vascular endothelial growth factor (VEGF; also called vascular permeability factor) is a secreted mitogen with distinct target cell specificity for vascular endothelial cells. Hypoxia upregulates VEGF expression, making it a likely mediator of the angiogenesis that occurs in poorly perfused tissues. The purpose of this study was to determine whether VEGF gene expression is upregulated in chronically stimulated skeletal muscles, where hypoxia is thought to trigger the growth of blood vessels. The right anterior tibialis and extensor digitorum longus muscles of 12 rats were stimulated electrically (10 Hz, 300 microseconds pulses) for up to 21 days by way of the peroneal motor nerve. The contralateral muscles served as control. Northern analysis showed that VEGF mRNA levels increased by approximately sixfold after 4 days of stimulation and then decreased gradually over the next several days. VEGF mRNA levels were still elevated by two- to threefold after 21 days of stimulation. Higher VEGF mRNA levels in the early stages of muscle stimulation and gradually decreasing levels in later stages are consistent with a metabolic hypothesis in which tissue oxygenation controls VEGF expression. These studies support the hypothesis that VEGF has a physiological role in promoting angiogenesis in stimulated skeletal muscle.
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Affiliation(s)
- J Hang
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson 39216-4505, USA
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30
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Adair TH, Hang J, Wells ML, Magee FD, Montani JP. Long-term electrical stimulation of rabbit skeletal muscle increases growth of paired arteries and veins. Am J Physiol 1995; 269:H717-24. [PMID: 7653637 DOI: 10.1152/ajpheart.1995.269.2.h717] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We tested whether chronic stimulation of skeletal muscle can increase the growth of paired arteries and veins in rabbit extensor digitorum longus muscle (EDL). The right EDL of female New Zealand White rabbits was stimulated via the common peroneal nerve at 10 Hz using 300 microseconds square waves at 3-4 V. Two-hour periods of stimulation was alternated with 4-h periods of rest, 7 days/wk for approximately 60 days. The left EDL served as control. The hindlimb vascular system was maximally dilated and perfuse-fixed with 3% glutaraldehyde and 2% paraformaldehyde at arterial and venous pressures of 80-100 and 15-20 mmHg, respectively. Muscles were postfixed in OsO4 and embedded in EPOX 812 resin. One millimeter-thick transverse sections were cut at uniform locations through the entire breadth of the muscle and analyzed using videomicroscopy along with computerized morphometric and stereological techniques. All paired arteries and veins on each full muscle section were analyzed. Chronic muscle stimulation caused the wall volume of paired arteries and veins to increase by an average of approximately twofold and the lumen volume to increase by an average of approximately threefold compared with the contralateral muscles. The wall-to-lumen area ratio of the arteries and veins was not affected. Muscle stimulation also caused the numerical density of arteries having a diameter > 100 microns to increase by approximately fourfold and the density of veins having a perimeter > 500 microns to increase by approximately 10-fold.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T H Adair
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson 39216-4505, USA
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31
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Hang J, Fleming JB, Wells ML, Adair TH. Miniaturized electrical stimulator with controllable duty cycles. Am J Physiol 1995; 268:H1373-8. [PMID: 7900890 DOI: 10.1152/ajpheart.1995.268.3.h1373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A stimulator with adjustable duty cycles is described for chronic electrical stimulation of skeletal muscles by way of a motor nerve. The stimulator is unique in that it can stimulate a muscle or group of muscles for 2-h intervals that alternate with variable periods of rest (2, 4, 6, 8, or 10 h). A given duty cycle is selected with a rotary switch at the beginning of an experiment and will continue automatically, without human intervention, for the duration of the experiment. Other features include an adjustable voltage output, a stimulation indicator light-emitting diode (LED), and a low-battery indicator LED. The stimulator is powered by two 9-V batteries or can be used with a bench-top power supply. The stimulation frequency (10 Hz) and pulse width (300 microseconds) are fixed in our design but can be changed to other values by substituting two of the resistors and one capacitor in accordance with simple formulas. We have used the stimulator in rat and rabbit experiments to stimulate the anterior tibialis and extensor digitorum longus muscles for up to 60 days. The timing and output of the stimulator were found to be stable and accurate over the entire 60-day period. The stimulator and batteries were carried in a jacket worn by the rabbits. In the rat experiments, the stimulator was used in a remote fashion with the electrical leads connected to the animals by way of a tethering system. In both animals, the electrodes were implanted adjacent to the common peroneal nerve.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J Hang
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson 39216
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32
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Abstract
We developed a stereological method for quantitating length density (Lv; vessel length per unit reference volume) of the arterial system. Accurate estimation of Lv for a sparse system of blood vessels in a three-dimensional specimen requires information on individual vessel orientation. The method we present extracts the necessary information on vessel orientation from profile geometry. Major and minor diameters of elliptical profiles of sectioned tubular structures are used to calculate Lv. The method does not require special sectioning alignment and does not assume a prior distribution of blood vessels; however, the method does assume that arteries are cylindrical. A physical model consisting of boiled spaghetti mixed with agar in a cylinder was used to test the stereological method. Measurements of over 1,000 elliptical profiles in 5 separate trials have demonstrated that the method can accurately estimate Lv with < 5% error even when tortuosity is high, i.e., when anisotrophy coefficient is 1.55. This method may facilitate a better understanding of the mechanisms of artery growth by making it possible to quantify linear growth of the arterial system.
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Affiliation(s)
- T H Adair
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson 39216-4505
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33
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Han G, Mack D, Hang J, Hunter E, Zeidan H, Han P. Evidence for heat-stable liver cytosol substance(s) capable of causing oxidative activation of fructose 1,6-bisphosphatase. Biochem Biophys Res Commun 1992; 182:600-8. [PMID: 1310387 DOI: 10.1016/0006-291x(92)91775-l] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The endogenous fructose 1,6-bisphosphatase (FBPase) in chicken liver extract undergoes a drastic increase in activity if the pH of the extract is in the alkaline range. Greater and more consistent activation occurs when purified FBPase, placed inside dialysis sack, is incubated in liver extract. Maximal activation (over 16-fold) is accompanied by the disappearance of 4 highly reactive sulfhydryl groups (SH) per molecule of enzyme. The activating effect of the extract remains essentially unchanged after heating to 100 degrees C. Activation can be reversed by dithiothreitol. These data show the existence in liver cytosol of heat-stable substance(s) capable of activating FBPase presumably by forming disulfide bonds with the enzyme's highly reactive SH groups.
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Affiliation(s)
- G Han
- Department of Chemistry, Morehouse College, Atlanta, Georgia 30314
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