251
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Levitt T, Fugelsang J, Xue Q, Crossley M. Predicting memory change following temporal lobectomy: Functional adequacy versus functional reserve. Arch Clin Neuropsychol 1998. [DOI: 10.1093/arclin/13.1.117a] [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: 11/13/2022] Open
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252
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Xue Q, Wang L, Newman R, Newman C, Graham H. Influence of the Hulless, Waxy Starch and Short-awn Genes on the Composition of Barleys. J Cereal Sci 1997. [DOI: 10.1006/jcrs.1996.0114] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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253
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Cane DE, Shim JH, Xue Q, Fitzsimons BC, Hohn TM. Trichodiene Synthase. Identification of Active Site Residues by Site-Directed Mutagenesis. Biochemistry 1997. [DOI: 10.1021/bi975011s] [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: 11/29/2022]
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254
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Cane DE, Xue Q, Van Epp JE, Tsantrizos YS. Enzymatic Formation of Isochamigrene, a Novel Sesquiterpene, by Alteration of the Aspartate-Rich Region of Trichodiene Synthase J. Am. Chem. Soc. 1996, 118, 8499−8500. J Am Chem Soc 1997. [DOI: 10.1021/ja975410a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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255
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Xue Q, Masuda K. A biomechanical study of fast throwing movements of the shoulder in baseball pitching. Chin Med J (Engl) 1997; 110:220-4. [PMID: 9594345] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE To define the biomechanic function of the shoulder in fast throwing movements in baseball pitching. METHODS Using NAC high-speed video and PIAS LA-555 computer system, overhand pitching movements carried out by 12 healthy Japanese professional baseball pitchers were analyzed in three dimensions. The pitching motion was displayed as stick to sick figures dynamically. RESULTS Pitching motion was a combination of translational and rotational movements. Acceleration and deceleration, being two typical motion patterns, worked sequentially through the anatomic link system from the pivot leg to the pitching hand. During the acceleration phase, the shoulder joint acted as a junction point and a fulcrum, supporting the rotational acceleration motion, shoulder forward flexion and elbow extension. According to the changing glenohumeral angles of the pitching shoulder, shearing force turned into tension force which worked on the anterior shoulder structures and then shifted to the posterior part of the joint. CONCLUSIONS In fast throwing motion, the shoulder functions as an important fulcrum to support the pitching arm during the acceleration phase. Avoiding excessive stress and shearing force on the joint components and enhancing coordination of muscle action are important to a successful throwing motion and the prevention of shoulder injury.
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Affiliation(s)
- Q Xue
- Department of Orthopaedics, Beijing Hospital, China
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256
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Abstract
Microfabricated multiple-channel glass chips were successfully interfaced to an electrospray ionization mass spectrometer (ESI-MS). The microchip device was fabricated by standard photolithographic, wet chemical etching, and thermal bonding procedures. A high voltage was applied individually from each buffer reservoir for spraying sample sequentially from each channel. With the sampling orifice of the MS grounded, it was found that a liquid flow of 100-200 nL/min was necessary to maintain a stable electrospray. The detection limit of the microchip MS experiment for myoglobin was found to be lower than 6 x 10(-8) M. Samples in 75% methanol were successfully analyzed with good sensitivity, as were aqueous samples. The parallel mutliple-channel microchip system allowed ESI-MS analysis of different samples of standard peptides and proteins in one chip.
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Affiliation(s)
- Q Xue
- Barnett Institute, Northeastern University, Boston, Massachusetts 02115, USA
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257
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Abstract
Ventricular late potentials (LP's) are high-frequency low-amplitude signals obtained from signal-averaged electrocardiograms (ECG's) [SAECG's]. LP's are useful in identifying patients prone to ventricular tachycardia (VT), spontaneous or inducible during electrophysiology testing. A combination of self-organizing and supervised artificial neural network (ANN) models was developed to identify patients with a positive electrophysiology (PEP) test for inducible ventricular tachycardia from patients with a negative electrophysiology (NEP) test using LP's. We have added morphology information of vector magnitude waveform to original set of three time-domain features of LP's, which are total QRS duration (TQRSD), high-frequency low-amplitude signal duration (HFLAD), and root-mean-square voltage (RMSV). Pattern recognition results from an ANN model with this combination feature set are superior to the results from Bayesian classification model based on conventional three time-domain features of SAECG. In order to increase the robustness of the recognition, a filtered QRS offset point is randomly shifted +/- 8 ms to form a fuzzy training set, which was to simulate the possible error in detecting QRS offset point of filtered SAECG. We also found that nonlinear transformation through the hidden layer of developed ANN model could increase Euclidean distance between PEP and NEP patterns.
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Affiliation(s)
- Q Xue
- Marquette Electronics Inc., Milwaukee, WI 53223 USA.
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258
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Huang G, Xue Q, Sun C. [Impingement syndrome of the subacromial area: analysis of 42 cases]. Zhonghua Wai Ke Za Zhi 1997; 35:35-7. [PMID: 10374506] [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: 02/12/2023]
Abstract
To create a new classification of subacromial impingement phenomena according to different etiology, we treated 42 cases of impingement syndrome. They were 29 male, and 23 females, with an average age of 45 years. 29 patients had typical subacromial pain are signs. Positive impingement test was found in 30 patients. Roentgenographic findings showed that the high density of the great tuberosity (GT) in 27 cases, 8 cases got the cystic changes around the CT, and exostosis formed on the G. T. in 3 cases. The abnormal acromion with sloped or over hanging form was found in 6 cases. 11 cases had an irregular inferior surface of the acromion in two cases with the spur formed at inferior surface of acromion. Four patients combined with calcium deposit at subacromial space. Space narrowing of the AH interval was in noted 12 cases. According to the X-ray findings, 35 cases were classified into the abnormal anatomy structure group. The other 7 patients were in dynamic impingement group. 13 cases of impingement syndrome combined with the complication of rotator cuff tear were treated by the Mclaughlin's procedure for repairing the rotator cuff with the acromion plasty. 11 patients were followed up for more than 6 months after operation. 7 cases had excellent results and 4 cases good results. This classification includes two kinds of impingement syndromes: anatomical of structural and dynamic or dysfunction.
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Affiliation(s)
- G Huang
- Department of Othopedics, Beijing Hospital
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259
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Xue Q, Dunayevskiy YM, Foret F, Karger BL. Integrated multichannel microchip electrospray ionization mass spectrometry: analysis of peptides from on-chip tryptic digestion of melittin. Rapid Commun Mass Spectrom 1997; 11:1253-1256. [PMID: 9276971 DOI: 10.1002/(sici)1097-0231(199708)11:12<1253::aid-rcm17>3.0.co;2-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In continuation of our work to develop an integrated multichannel microchip interfaced to electrospray mass spectrometry (ESI-MS), this paper demonstrates one of several applications of this approach in monitoring tryptic digestion products. The multichannel microchip allowed integration of sample preparation onto the microchip to facilitate the analysis process. Melittin was selected as a model oligopeptide because it possesses a cluster of four adjacent basic residues which enable probing the site specificity of trypsin as a function of digest times. Reactions were performed on-chip in different wells for specific time periods and then analyzed by infusion from the microchip by ESI-MS, using leucine enkephalin as internal standard. The rate of formation and disappearance of the molecular ion and individual fragments was followed for a melittin to trypsin concentration ratio of 300:1. The results indicate the potential of integrating enzymatic reactions with multichannel microchip ESI-MS for automated optimization of reaction condition while consuming only small amounts of sample.
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Affiliation(s)
- Q Xue
- Barnett Institute, Northeastern University, Boston, MA 02115, USA
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260
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Xia JL, Yang BH, Tang ZY, Sun FX, Xue Q, Gao DM. Inhibitory effect of the angiogenesis inhibitor TNP-470 on tumor growth and metastasis in nude mice bearing human hepatocellular carcinoma. J Cancer Res Clin Oncol 1997; 123:383-7. [PMID: 9260590 DOI: 10.1007/bf01240121] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [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: 02/05/2023]
Abstract
The antitumor and anti-metastatic effects of a potent angiogenesis inhibitor, O-(chloroacetyl-carbamoyl)fumagillol (TNP-470), was investigated in a highly metastatic model of human hepatocellular carcinoma-LCI-D20. Small pieces of LCI-D20 tumor tissue were implanted subcutaneously into the right axillary region of 24 nude mice; the mice were then randomized into two groups. To one group, TNP-470 30 mg/kg was given as a subcutaneous injection every other day from day 1 to day 15 and the mice were sacrificed on day 26. An antitumor effect of TNP-470 was clearly demonstrated by tumor weight (0.97 +/- 0.34 g compared to 2.04 +/- 0.34 g, P < 0.001) and alpha-Fetoprotein value (93 +/- 59 micrograms/L compared to 769 +/- 282 micrograms/L, P < 0.001). There was also an anti-metastatic effect of TNP-470. Lung metastases developed in only 1 of 12 mice in the treated group, while they developed in 6 of mice of the control group. No severe side-effect of TNP-470 was found in this study. In vitro study revealed that the purified hepatoma cells were insensitive to TNP-470 (the 50% inhibitory concentration was 43 micrograms/ml). These results suggest that the angiogenesis inhibitor TNP-470 has both strong antitumor and anti-metastatic effects on a human hepatocellular carcinoma model in nude mice.
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Affiliation(s)
- J L Xia
- Liver Cancer Institute, Zhongshan Hospital, Shanghai Medical University, People's Republic of China
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261
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Cane DE, Xue Q, Fitzsimons BC. Trichodiene synthase. Probing the role of the highly conserved aspartate-rich region by site-directed mutagenesis. Biochemistry 1996; 35:12369-76. [PMID: 8823172 DOI: 10.1021/bi961344y] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.7] [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: 02/02/2023]
Abstract
Trichodiene synthase catalyzes the cyclization of farnesyl diphosphate to the sesquiterpene hydrocarbon trichodiene. The enzyme normally requires a divalent cation, Mg2+, which can be substituted by Mn2+. Trichodiene synthase from Fusarium sporotrichioides has a highly conserved aspartate rich region, aa 100-104 (DDSKD). Three mutants were constructed by site-directed mutagenesis in which each aspartate residue was individually replaced by glutamate. The mutants were each overexpressed and purified to homogeneity. The importance of Asp100 and Asp101 for catalysis was established by the observation of an increase in Km as well as a reduction in kcat in the corresponding Glu mutants. Replacement of the Asp104 residue with Glu had little effect on either Km or kcat. All three mutants produced anomalous sesquiterpene products in addition to trichodiene when incubated with farnesyl diphosphate. Interestingly, when Mg2+ was replaced by Mn2+ in the incubation buffer, the kcat/Km of both wild type trichodiene synthase and the D104E dropped significantly, while those of the other two mutants were not much affected. The proportion of anomalous products increased significantly when the D100E and D101E mutants were incubated in the presence of Mn2+. These observations all lend weight to the proposal that the aspartate residues mediate substrate binding by chelation of the divalent metal ion. Asp100 and Asp101 appear to play a relatively more important role than Asp104.
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Affiliation(s)
- D E Cane
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA.
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262
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Cane DE, Xue Q, Van Epp JE, Tsantrizos YS. Enzymatic Formation of Isochamigrene, a Novel Sesquiterpene, by Alteration of the Aspartate-Rich Region of Trichodiene Synthase. J Am Chem Soc 1996. [DOI: 10.1021/ja961897w] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- David E. Cane
- Department of Chemistry, Box H Brown University Providence, Rhode Island 02912
| | - Qun Xue
- Department of Chemistry, Box H Brown University Providence, Rhode Island 02912
| | - James E. Van Epp
- Department of Chemistry, Box H Brown University Providence, Rhode Island 02912
| | - Youla S. Tsantrizos
- Department of Chemistry and Biochemistry Concordia University 1455, de Maisonneuve Boulevard West Montreal, Québec H3G 1M8 Canada
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263
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Sun FX, Tang ZY, Liu KD, Xue Q, Gao DM, Yu YQ, Zhou XD, Ma ZC. Metastatic models of human liver cancer in nude mice orthotopically constructed by using histologically intact patient specimens. J Cancer Res Clin Oncol 1996; 122:397-402. [PMID: 8690749 DOI: 10.1007/bf01212878] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [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: 02/01/2023]
Abstract
In this study of orthotopic implantation of histologically intact surgical specimens, the authors constructed metastatic models of human hepatocellular carcinoma (HCC) in nude mice. Histologically intact human liver cancer specimens, derived from patients, were implanted directly into the liver of nude mice, and their orthotopic growth and metastases were observed. The transplantability and metastatic rate of two specimen groups (primary and metastatic lesions) were analysed. alpha-Fetoprotein (AFP) was also determined in transplanted tumours by an immunohistochemical method. Orthotopic growth was observed in 14 of 30 transplanted specimens and formation of metastases in 7 cases, which exhibited the variety of clinical behaviours seen in patients with HCC. These behaviours included local growth, regional invasion, spontaneous intrahepatic, lymph node and lung metastasis and peritoneal seeding. In two groups the growth rate of metastatic lesions following implantation was clearly higher than that of primary tumours. Chromosome analysis from locally growing tumours confirmed their morphologically human origin. An immunohistochemical study showed that implanted tumours originating from AFP-positive specimens maintained AFP expression. These results indicated that the animal models should prove valuable for developing new treatment modalities and studying the mechanism of metastasis of human HCC.
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Affiliation(s)
- F X Sun
- Liver Cancer Institute, Shanghai Medical University, P.R. China
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264
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Sun FX, Tang ZY, Lui KD, Ye SL, Xue Q, Gao DM, Ma ZC. Establishment of a metastatic model of human hepatocellular carcinoma in nude mice via orthotopic implantation of histologically intact tissues. Int J Cancer 1996. [PMID: 8603818 DOI: 10.1002/(sici)1097-0215(19960410)66:2<239::aid-ijc17>3.0.co;2-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A highly metastatic LCI-D20 model of human hepatocellular carcinoma (HCC) was obtained via orthotopic implantation of a histologically preserved metastatic tumour selected from 1 of 30 surgical specimens, and had been maintained for 18 passages in nude mice. All mice with transplanted tumours exhibited 100% transplantability and metastatic ability, as well as various manifestations reminiscent of tumour behaviour in HCC patients. These included: local growth, regional invasion, spontaneous metastasis to liver, lymph nodes and lungs, and peritoneal seeding. Histological characteristics of the LCI-D20 tumour were similar to those of the original tumour. Karyotypic analysis revealed heteroploid cells. Immunohistochemically, expression of AFP and HBxAG was shown. Our nude mouse model with its high metastatic rate and short latency period could be an interesting tool for the study of human HCC.
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Affiliation(s)
- F X Sun
- Liver Cancer Institute, Shanghai Medical University, People's Republic of China
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265
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Sun FX, Tang ZY, Lui KD, Ye SL, Xue Q, Gao DM, Ma ZC. Establishment of a metastatic model of human hepatocellular carcinoma in nude mice via orthotopic implantation of histologically intact tissues. Int J Cancer 1996; 66:239-43. [PMID: 8603818 DOI: 10.1002/(sici)1097-0215(19960410)66:2<239::aid-ijc17>3.0.co;2-7] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.9] [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: 01/31/2023]
Abstract
A highly metastatic LCI-D20 model of human hepatocellular carcinoma (HCC) was obtained via orthotopic implantation of a histologically preserved metastatic tumour selected from 1 of 30 surgical specimens, and had been maintained for 18 passages in nude mice. All mice with transplanted tumours exhibited 100% transplantability and metastatic ability, as well as various manifestations reminiscent of tumour behaviour in HCC patients. These included: local growth, regional invasion, spontaneous metastasis to liver, lymph nodes and lungs, and peritoneal seeding. Histological characteristics of the LCI-D20 tumour were similar to those of the original tumour. Karyotypic analysis revealed heteroploid cells. Immunohistochemically, expression of AFP and HBxAG was shown. Our nude mouse model with its high metastatic rate and short latency period could be an interesting tool for the study of human HCC.
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Affiliation(s)
- F X Sun
- Liver Cancer Institute, Shanghai Medical University, People's Republic of China
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266
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Duan X, Li X, Xue Q, Abo-el-Saad M, Xu D, Wu R. Transgenic rice plants harboring an introduced potato proteinase inhibitor II gene are insect resistant. Nat Biotechnol 1996; 14:494-8. [PMID: 9630927 DOI: 10.1038/nbt0496-494] [Citation(s) in RCA: 224] [Impact Index Per Article: 8.0] [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: 02/07/2023]
Abstract
We introduced the potato proteinase inhibitor II (PINII) gene (pin2) into several Japonica rice varieties, and regenerated a large number of transgenic rice plants. Wound-inducible expression of the pin2 gene driven by its own promoter, together with the first intron of the rice actin 1 gene (act1), resulted in high-level accumulation of the PINII protein in the transgenic plants. The introduced pin2 gene was stably inherited in the second, third, and fourth generations, as shown by molecular analyses. Based on data from the molecular analyses, several homozygous transgenic lines were obtained. Bioassay for insect resistance with the fifth-generation transgenic rice plants showed that transgenic rice plants had increased resistance to a major rice insect pest, pink stem borer (Sesamia inferens). Thus, introduction of an insecticidal proteinase inhibitor gene into cereal plants can be used as a general strategy for control of insect pests.
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Affiliation(s)
- X Duan
- Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853, USA
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267
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Xue Q, Yeung ES. Determination of lactate dehydrogenase isoenzymes in single lymphocytes from normal and leukemia cell lines. J Chromatogr B Biomed Appl 1996; 677:233-40. [PMID: 8704926 DOI: 10.1016/0378-4347(95)00467-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This work demonstrates that our previously developed technique for single-erythrocyte analysis by capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) can be applied to study individual lymphocytes, with some modification in the cell lysing procedure. A tesla coil was shown to be capable of lysing the lymphocyte cells inside the capillary. The electromagnetic field induced by the tesla coil was believed to be responsible for breaking the cell membrane. The lactate dehydrogenase (LDH) isoenzyme activities and relative ratios between different LDH isoenzymes were measured for normal lymphocytes as well as B-type and T-type acute lymphoblastic leukemia cells. Both the LDH activity and the isoenzyme ratios show large variations among individual cells. The former is expected due to variations in cell size. The latter implies that single-cell measurements are less useful than the average values over a cell population as markers for leukemia.
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Affiliation(s)
- Q Xue
- Ames Laboratory-USDOE, Iowa State University 50011, USA
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268
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Affiliation(s)
- David E. Cane
- Department of Chemistry, Box H, Brown University Providence, Rhode Island 02912
| | - Qun Xue
- Department of Chemistry, Box H, Brown University Providence, Rhode Island 02912
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269
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Xue Q, Ogino T, Hasegawa Y, Shinohara H, Sakurai T. Adsorption and film growth of C60 on the GaAs(001) 2 x 6 surface by molecular-beam epitaxy. Phys Rev B Condens Matter 1996; 53:1985-1989. [PMID: 9983660 DOI: 10.1103/physrevb.53.1985] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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270
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Xue Q, Gong Y, Drake DL, Qian J, Coleman RV. Impurity-induced modulations in PdxNbSe3 coupled to charge-density-wave formation. Phys Rev B Condens Matter 1996; 53:1068-1071. [PMID: 9983557 DOI: 10.1103/physrevb.53.1068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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271
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Abstract
As part of the International Electrotechnical Commission's (IEC) efforts to develop standards for interpretive electrocardiographs, electrocardiograms (ECGs) of the Common Standards of Electrocardiography (CSE) multilead measurement database were processed to (1) determine whether original ECG data would offer any advantage over cycle-repeated (artificial) ECGs and (2) compare the "clean" ECGs selected for interval measurement compliance testing (n = 100) with the remaining 25 "noisy" or nonsinus rhythm ECGs. Two sets of CSE measurement ECGs, namely, 125 original ECGs of the MO1 series and 125 artificial ECGs of the MA1 series were divided into 100 IEC-selected clean ECGs with good P and T waves and 25 noisy or nonsinus ECGs and processed for global wave duration and interval measurements (P duration, PR interval, QRS duration, and QT interval). The measured duration and interval values were compared against the CSE reference values (medians of referee values for 25 physician overread ECGs and medians of interpretive programs for the rest) to compute the measurement "differences". Also, the data of the median cardiac complex were evaluated for noise content. The original ECG data gave consistently smaller differences for all of the four measurements than the differences with the artificial ECG data. The noise levels in the median complexes formed from the original ECG data were significantly lower than the noise levels in the median complexes from the artificial ECG data. The noise levels in the medians of the 100 clean ECGs were lower than the noise levels in the medians of the 25 noisy ECGs for both the original and artificial ECG data.
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Affiliation(s)
- B R Reddy
- Marquette Electronics, Milwaukee, Wisconsin 53223, USA
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272
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Abstract
The nucleotide sequence of the phage 186 genome from 46.3-52.5% was determined and was found to contain two open reading frames highly similar to the tail sheath gene FI and tail tube gene FII of phage P2. The reading frames were identified as genes J and I by marker rescue experiments. A late promoter pJ was identified by galK reporter and primer extension studies. Northern analysis suggested that the pJ transcript predominantly terminated immediately after gene I, although some transcripts could extend to the terminator tB at 67.3%.
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Affiliation(s)
- Q Xue
- Department of Biochemistry, University of Adelaide, South Australia
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273
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Abstract
We present here the nucleotide sequence of the tail fiber genes of phage 186. Marker rescue was used to associate an open reading frame (ORF) of 462 codons with the previously known tail gene K. A downstream ORF, encoding a 166-amino-acid product, was designated orf 45. Comparative studies suggested that K encodes the tail fiber protein and that orf 45 encodes an assembly protein. K protein contains a succession of short amino acid sequences (motifs) that are homologous with sequences from the tail fiber proteins of unrelated bacteriophages. The fact that these sequence motifs are variously present in the tail fiber proteins of unrelated bacteriophages has been advanced as evidence for horizontal transfer in the evolution of the associated tail fiber genes. However, the fact that the order of the various motifs in the proteins is invariant emphasizes the probability that independent divergence from a common ancestor also played a major role in the evolution of the tail fiber genes.
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Affiliation(s)
- Q Xue
- Department of Biochemistry, University of Adelaide, South Australia
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274
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Gong Y, Xue Q, Drake DL, Qian J, Coleman RV. Impurity-induced modulations in NbSe3 detected by atomic-force microscopy. Phys Rev B Condens Matter 1995; 51:12975-12988. [PMID: 9978092 DOI: 10.1103/physrevb.51.12975] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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275
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Xue Q, Hashizume T, Zhou JM, Sakata T, Ohno T, Sakurai T. Structures of the Ga-rich 4 x 2 and 4 x 6 reconstructions of the GaAs(001) surface. Phys Rev Lett 1995; 74:3177-3180. [PMID: 10058131 DOI: 10.1103/physrevlett.74.3177] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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276
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Abstract
Derivatization of 5,5'-dithiobis(2-nitrobenzoic acid)-treated trichodiene synthase with [methyl-14C]methyl methanethiosulfonate and analysis of the derived tryptic peptides suggested the presence of two cysteine residues at the active site. The corresponding C146A and C190A mutants were constructed by site-directed mutagenesis. The C190A mutant displayed partial but significantly reduced activity, with a reduction in kcat/Km of 3000 compared to the wild-type trichodiene synthase, while the C146A mutant was essentially inactive. A hybrid trichodiene synthase, constructed from amino acids 1-309 of the Fusarium sporotrichioides enzyme and amino acids 310-383 of the Gibberella pulicaris cyclase, had steady state kinetic parameters nearly identical to those of the wild-type F. sporotrichioides enzyme. From this parent hybrid, a series of mutants was constructed by site-directed mutagenesis in which the amino acids in the base-rich region, 302-306 (DRRYR), were systematically modified. Three of these mutants were overexpressed and purified to homogeneity. The importance of Arg304 for catalysis was established by the observation that the R304K mutant showed a more than 25-fold increase in Km, as well as a 200-fold reduction in kcat. In addition, analysis of the incubation products of the R304K mutant by gas chromatography-mass spectrometry (GC-MS) indicated that farnesyl diphosphate was converted not only to trichodiene but to at least two additional C15H24 hydrocarbons, mle 204. Replacement of the Tyr305 residue of trichodiene synthase with Phe had little effect on kcat, while increasing the Km by a factor of ca. 7-8.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D E Cane
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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277
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Abstract
The substrate specificity of the sesquiterpene synthase trichodiene synthase was examined by determining the Vmax and Km parameters for the natural substrate, trans,trans-farnesyl diphosphate (1), its stereoisomer, cis,trans-farnesyl diphosphate, and the tertiary allylic isomer, (3R)-nerolidyl diphosphate (3), using both the native fungal and recombinant enzymes. A series of farnesyl diphosphate analogs, 15, 16, 20, 7, 8, and 9, was also tested as inhibitors of trichodiene synthase. 10-Fluorofarnesyl diphosphate (15) was the most effective competitive inhibitor, with a K1 of 16 nM compared to the Km for 1 of 87 nM, while the ether analog of farnesyl diphosphate, 8, an extremely potent inhibitor of squalene synthase, showed only modest inhibition of trichodiene synthase, with a K1/Km of 70.
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Affiliation(s)
- D E Cane
- Department of Chemistry, Brown University, Providence, Rhode Island 02912
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278
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Abstract
Much attention has been focused recently on the detection and physical characterization of individual molecules. Using such methods to study the chemical properties, such as reactivity, of single molecules offers the potential to investigate how these might vary from molecule to molecule, and for individual molecules as a function of time. The complex structures of biomolecules such as enzymes make them particularly attractive targets for studying how subtle changes or differences at the molecular level might influence chemical reactivity. We have shown previously that very small (zeptomole) amounts of enzymes can be studied using a fluorescence microassay; single enzyme molecules have also been detected in oil-dispersed droplets by fluorescence microscopy. Here we report the observation of reactions of individual molecules of lactate dehydrogenase (LDH-1), which produces NADH from lactate and nicotinamide adenine dinucleotide (NAD+). When they are present at very low concentrations in a narrow capillary, each enzyme molecule produces a discrete zone of NADH; these can be manipulated electrophoretically and monitored by fluorescence spectroscopy. We find that the activity of individual electrophoretically pure enzyme molecules can vary by up to a factor of four, and that these activities remain unchanged over a two-hour period. We suggest that the origin of the activity differences may lie in the presence of several stable forms of the enzyme.
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Affiliation(s)
- Q Xue
- Ames Laboratory-USDOE, Iowa State University, Ames 50011
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279
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Hashizume T, Xue Q, Ichimiya A, Sakurai T. Determination of the surface structures of the GaAs(001)-(2 x 4) As-rich phase. Phys Rev B Condens Matter 1995; 51:4200-4212. [PMID: 9979259 DOI: 10.1103/physrevb.51.4200] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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280
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Xue Q. Neurochemistry in China. Chin Med J (Engl) 1995; 108:152-6. [PMID: 7774393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Affiliation(s)
- Q Xue
- Department of Neurology, Beijing Friendship Hospital
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281
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Abstract
Analysis of high frequency (150-250 Hz) in the signal-averaged electrocardiogram (SAECG) is one of the emerging methods for detecting vessel patency in acute myocardial infarction following thrombolytic therapy and angioplasty. Root-mean-square voltage (RMSV) of the filtered QRS has been used in earlier studies to detect reperfusion; however, previous analysis indicated that RMSV is sensitive to residual noise in the SAECG and errors in QRS delineation (onset/offset). A new measurement is proposed, high-frequency energy (HFQE), and the robustness of the RMSV and HFQE was evaluated for simulated errors in QRS delineation. In this study, two measures (RMSV and HFQE) were tested on 24 control subjects and 21 patients undergoing thrombolytic therapy. Results indicate that unfiltered QRS duration is more stable than filtered QRS duration for the control subjects and patients and that HFQE had less fluctuation than RMSV in thrombolytic therapy patients. In the control group, HFQE was sensitive to the amplitude variation of the filtered SAECG. Therefore, another new measurement is proposed high-frequency integral of absolute value (HFAV), for reducing the sensitivity to amplitude changes in the filtered SAECG. This new feature was tested on control subjects and was found to be more stable than HFQE. In the thrombolitic therapy group, HFAV provided similar information as HFQE. These three measurements-RMSV, HFQE, and HFAV-provide a comprehensive analysis of the high-frequency SAECG for detecting vessel patency and reocclusion. Relative merits of these measures need to be evaluated on a larger database of patients undergoing thrombolysis and angioplasty for acute myocardial infarction.
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Affiliation(s)
- Q Xue
- Marquette Electronics, Inc. Milwaukee, Wisconsin 53223, USA
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282
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Xue Q, Earle ED. Plant regeneration from protoplasts of cytoplasmic male sterile lines of rice (Oryza sativa L.). Plant Cell Rep 1995; 15:76-81. [PMID: 24185659 DOI: 10.1007/bf01690258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/1994] [Revised: 03/16/1995] [Indexed: 06/02/2023]
Abstract
This study compared plant regeneration from protoplasts isolated from suspension cultures of threeJaponica rice (Oryza sativa L.) lines with different male sterile cytoplasms. More than 180 green plants were regenerated from protoplasts from 5-8 month old suspensions of IR58024A, a line with the WA type of cytoplasmic male sterility (CMS). About 40% of the calli recovered from protoplasts produced green plants. ShuangbaiA (BT type of CMS) and Tai2A (Dian I type of CMS), both from Zhejiang province of China, responded less well in culture. ShuangbaiA produced green plants from 6.6% of calli, although initial protoplast yield per gram fresh weight was higher than for IR58024A. Tai2A showed lower protoplast yield, and only 1.1% of the calli produced green plants. Flow cytometric analyses of nuclear DNA content indicated that many of the regenerated plants were tetraploid. The percentage of tetraploids varied in the different lines. The male sterile characteristics of the original lines were maintained in the regenerated plants. Pollen abortion occured earliest in IR58024A and latest in Tai2A. IR58024A is a promising rice genotype for use as a recipient in direct gene transfer experiments.
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Affiliation(s)
- Q Xue
- Department of Plant Breeding and Biometry, Cornell University, 14853-1902, Ithaca, NY, USA
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283
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Abstract
Trace amounts of enzymes within single human erythrocytes can be quantified by a combination of on-column reaction and capillary electrophoresis. A detection limit of 1.3 x 10(-21) mol of LDH was achieved with laser-induced fluorescence by monitoring the product of the enzyme-catalyzed reaction between lactate and NAD+. Single erythrocyte analysis clearly isolates the major forms of LDH. The variation of total LDH activity in a population of cells from a single individual is large, but the relative activities of the isoenzymes LDH-1 and LDH-2 are fairly constant. This can be explained by the distribution of cell age in the population. A lower enzyme activity is indicative of senescence. The efficient separation of different LDH forms and the high detection sensitivity opens up the possibility of multiple-enzyme assays with a single mammalian cell.
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Affiliation(s)
- Q Xue
- Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames 50011
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284
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Wang XD, Xue Q, Hashizume T, Shinohara H, Nishina Y, Sakurai T. STM study on the interactions of C70 with the Si(100)2 x 1 surface. Phys Rev B Condens Matter 1994; 49:7754-7758. [PMID: 10009524 DOI: 10.1103/physrevb.49.7754] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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285
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Abstract
A scheme of using fluorescein as the fluorophore for indirect detection of anions was demonstrated. This system is quite stable at a fluorescein concentration of 100 microM even without any other buffer components. Different injection modes affect the limit of detection (LOD). A LOD of about 20 amol was obtained for lactate under optimal conditions. Lactate and pyruvate in the intracellular fluid of erythrocytes were measured in this manner. The average amounts in a single erythrocyte for lactate and pyruvate are 1.3 and 2.1 fmol, respectively, or a ratio of 1.6 for pyruvate to lactate. Variations of the absolute amounts and the ratios are fairly large among a group of 27 cells examined. This is consistent with the difference of cells in size and composition. Although the migration times changed by up to 20% during a series of runs from the influence of concomitants in the cells, the migration time ratio was maintained around 1.072 with 3% relative standard deviation.
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Affiliation(s)
- Q Xue
- Department of Chemistry, Iowa State University, Ames 50011
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286
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Dai S, Cheng J, Sun R, Duan J, Yuan Q, Sun Y, Yan Y, Xue Q. Hemodynamic and nonhemodynamic mechanisms of experimental pulmonary edema in rats and the effects of anisodamine and tetramethylpyrazine--estimation of blood gas analysis, RBC superoxide dismutase and prostaglandin E2 in plasma and bronchoalveolar lavage (Part 3). Chin Med Sci J 1993; 8:210-4. [PMID: 8032066] [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: 01/28/2023]
Abstract
Anisodamine (ADM, 654-2, 30 mg/kg) and tetramethylpyrazine (TMP, 120 mg/kg) have shown an apparent preventive effect on pulmonary edema (PE). In this study, the nonhemodynamic mechanism was studied: The dynamic changes of PaO2, O2Sat, PaCO2, and blood pH were measured, and RBC superoxide dismutase (SOD) and plasma and bronchoalveolar lavage (BAL) PGE2 levels were estimated. It was concluded that ADM and TMP exerted inhibitory effects on the hypoxic state. The ability of ADM and TMP to adjust RBC SOD and PGE2 levels may be one of the preventive mechanisms of the drugs.
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Affiliation(s)
- S Dai
- Institute of Basic Medical Sciences, CAMS, Beijing
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287
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Dai Z, Xue Q, Gong Y, Slough CG, Coleman RV. Scanning-probe-microscopy studies of superlattice structures and density-wave structures in 2H-NbSe2, 2H-TaSe2, and 2H-TaS2 induced by Fe doping. Phys Rev B Condens Matter 1993; 48:14543-14555. [PMID: 10007877 DOI: 10.1103/physrevb.48.14543] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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288
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Gong Y, Xue Q, Dai Z, Slough CG, Coleman RV, Falicov LM. Modulation of the crystal structure in quasi-one-dimensional solids induced by impurities: An atomic-force microscope study. Phys Rev Lett 1993; 71:3303-3306. [PMID: 10054939 DOI: 10.1103/physrevlett.71.3303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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289
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Dai S, Su S, Cao Y, Sun R, Fan Y, Zhang H, Si Q, Xue Q. Hemodynamic and nonhemodynamic mechanism of experimental pulmonary edema in rats and the effect of anisodamine and tetramethylpyrazine--electron microscopic observation and measurement of pulmonary arterial, pulmonary arterial wedge and systemic arterial pressure (Part 2). Chin Med Sci J 1993; 8:129-33. [PMID: 7908230] [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: 01/27/2023]
Abstract
The pulmonary edema (PE) induced by adrenaline (AD) administration is similar to neurogenic PE. Anisodamine (ADM, 654-2, 30 mg/kg) and tetramethylpyrazine (TMP, 120 mg/kg) have shown significant preventive effects. Electron microscopic observation was carried out to study the changes of microvascular permeability, and the dynamic change of mean pulmonary arterial pressure (PAP, 40 rats), mean pulmonary arterial wedge pressure (PAWP, 20 rats) and mean carotid arterial pressure (CAP) were also measured. The results suggested that both ADM and TMP have significant inhibitory effects on PAWP and CAP increase, as well as on the damage responsible for the increase of microvascular and alveolar permeability.
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Affiliation(s)
- S Dai
- Institute of Basic Medical Sciences, CAMS, Beijing
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290
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Xue Q, Dai Z, Gong Y, Slough CG, Coleman RV. Charge-density-wave structure and a metal-insulator transition in CrxNbSe3 detected by atomic force microscopy and transport measurements. Phys Rev B Condens Matter 1993; 48:1986-1988. [PMID: 10008580 DOI: 10.1103/physrevb.48.1986] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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291
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Dai S, Xue Q, Sun R, Wang S, Li C, Wu Y, Si Q, Hu S. Hemodynamic and nonhemodynamic mechanisms of experimental pulmonary edema in rats and the effect of anisodamine and tetramethylpyrazine. Part 1: Survival rate, pulmonary index, pathological change and pulmonary vascular permeability. Chin Med Sci J 1993; 8:72-6. [PMID: 8292802] [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: 01/29/2023]
Abstract
Pulmonary edema (PE) which is similar to the neurogenic type was induced by adrenaline (AD) administration (0.1 mg/kg) in rats. Acute progressive respiratory distress, cyanosis and dyspnea occurred. All the experimental animals in the PE group died within 20 min after AD injection, with a pulmonary index (PI) of 1.70 +/- 0.47 (mean +/- S) which was much higher than that in the normal group. The mortality rate was 100%. It was found that in rats with PE, a protein-rich fluid filled the alveolar and interstitial spaces, and ecchymosis occurred. The capillary permeability as estimated by Evans blue injection showed that Evans blue from extraction fluid and bronchoalveolar lavage (BAL) in the PE rats was at a much higher level than that in the normal control (NC) rats. In anisodamine (ADM, 654-2) and tetramethylpyrazine (TMP) treated rats, almost all the damage was diminished or absent, and the mortality rates were decreased from 100% to 4.4% and 20%, respectively. 654-2 and TMP could significantly inhibit the increase of pulmonary permeability.
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Affiliation(s)
- S Dai
- Institute of Basic Medical Sciences, CAMS, Beijing
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292
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Xue Q, Hou J, Li Y. [Age-related morphological changes in the suprachiasmatic nucleus of the rat hypothalamus]. Hua Xi Yi Ke Da Xue Xue Bao 1992; 23:314-7. [PMID: 1298724] [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: 12/26/2022]
Abstract
A comparative ultrastructural investigation of the hypothalamic suprachiasmatic nuclei (SCN) of young, adult and senescent SD male rats was carried out. The neurons and neuroglial cells in SCN of the senile rats displayed more lipofuscin (Lipo) accumulation in comparison with those of the younger animals. Golgi apparatus (Gol) of the three age groups converted from well-ordered cisternae to irregular ones with extensive dilatation and vacuolization. More neuroglial cells with broader somatic membrane appositional to that of neuron participated in satellitosis in the senile age group. Some unusual structures such as special arrangements of the rough endoplasmic reticula and multilamellar neuroglial envelope (Mge) wrapping neurite were encountered in the perikarya of some neurons or SCN neuropile respectively.
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293
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Xue Q, Hou J. [Age-related change of synaptic number in the suprachiasmatic nucleus of the rat hypothalamus]. Hua Xi Yi Ke Da Xue Xue Bao 1992; 23:160-3. [PMID: 1452148] [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: 12/27/2022]
Abstract
Numerical changes of the synapses in the hypothalamic suprachiasmatic nuclei (SCN) of rats at different ages were investigated with electron microscope, The population of the major SCN synapses formed with dendrite and total number of synapses were found to be reduced with advancing age. Compared with the young animal group, the synaptic number was statistically different from that in the adult or senescent group. As a result of these changes, the function of SCN might decline with aging.
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Affiliation(s)
- Q Xue
- Department of Histology and Embryology, Lanzhou Medical College
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294
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Abstract
We have developed an adaptive matched filtering algorithm based upon an artificial neural network (ANN) for QRS detection. We use an ANN adaptive whitening filter to model the lower frequencies of the ECG which are inherently nonlinear and nonstationary. The residual signal which contains mostly higher frequency QRS complex energy is then passed through a linear matched filter to detect the location of the QRS complex. We developed an algorithm to adaptively update the matched filter template from the detected QRS complex in the ECG signal itself so that the template can be customized to an individual subject. This ANN whitening filter is very effective at removing the time-varying, nonlinear noise characteristic of ECG signals. Using this novel approach, the detection rate for a very noisy patient record in the MIT/BIH arrhythmia database is 99.5%, which compares favorably to the 97.5% obtained using a linear adaptive whitening filter and the 96.5% achieved with a bandpass filtering method.
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Affiliation(s)
- Q Xue
- Department of Electrical and Computer Engineering, University of Wisconsin, Madison 53706
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295
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Xie J, Xue Q, Wang L, Huang Y, Wang J. Effect of hypoxia on the pulmonary beta and alpha 1 adrenoceptors in rats. Chin Med Sci J 1991; 6:217-22. [PMID: 1667484] [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: 12/28/2022]
Abstract
The present study was designed to investigate the effect of hypoxia on the pulmonary adrenoceptors in rats. The density and distribution of pulmonary adrenoceptors were studied by using radioligand binding techniques and autoradiography. The beta adrenoceptors in lung homogenates were found to decrease by 24 h of hypoxia, and to unexpectedly increase at 1 week of hypoxia. Exposure to hypoxia for 2 and 4 weeks led to another decrease in beta adrenoceptors. In contrast, the alpha 1 adrenoceptors were increased markedly at 24 h and 4 weeks of hypoxia. A somewhat higher density of alpha 1 adrenoceptors was also found at 1 week and 7 weeks of hypoxia. The affinity of beta and alpha 1 adrenoceptors did not change. Using a computer image analysis system, beta adrenoceptors were found to be present in higher density in bronchioles than in pulmonary blood vessels before and during hypoxia, while the reverse was true of alpha 1 adrenoceptors. Both beta and alpha 1 adrenoceptors were found in high densities in the parenchyma.
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Affiliation(s)
- J Xie
- Institute of Basic Medical Sciences, CAMS, Beijing
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