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Li Z, Chen Z, Cai M. [A case of ancylostomiasis manifested by fresh bloody stool]. ZHONGGUO JI SHENG CHONG XUE YU JI SHENG CHONG BING ZA ZHI = CHINESE JOURNAL OF PARASITOLOGY & PARASITIC DISEASES 2003; 17:333. [PMID: 12563724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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Cheng Y, Zhang Y, Lin C, Zhan Z, Yu X, Lin J, Cai M, Che W. [Taxonomic studies on Echinochasmus fujienensis and its related species by random amplified polymorphic DNA analysis and experimental infection]. ZHONGGUO JI SHENG CHONG XUE YU JI SHENG CHONG BING ZA ZHI = CHINESE JOURNAL OF PARASITOLOGY & PARASITIC DISEASES 2003; 17:135-9. [PMID: 12563828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
AIM To explore the identification and differentiation of Echinochasmus fujianensis, Echinochasmus japonicus(Jiangxi strain and Fujian strain), Echinochasmus liliputanus Anhui and Echinochasmus per foliatus Hubei. METHODS Random amplified polymorphic DNA analysis (RAPD) and experimental animal infection were performed. RESULTS 469 polymorphic DNA fragments were obtained by 28 primers from 4 Echinochasmus species and strains in Fujian, Anhui and Jiangxi. 20.8% and 97.6% of the fragments in Echinochasmus fujianensis were the same as those in Echinochasmus japonicus Fujian strain and in Echinochasmus liliputanus Anhui, respectively, 99.7% of the fragments were the same between Echinochasmus japonicus Jiangxi strain and Fujian strain. CONCLUSION Echinochasmus fujianensis and Echinochasmus liliputanus Anhui are the same species. Echinochasmus fujienensis is an independent species different from Echinochasmus japonicus. Polyinfection of Echinochasmus fujianensis, Echinochasmus japonicus and Echinochasmus perfoliatus exist in all the 3 provinces, Hubei, Anbui and Fujian, of which Echinochasmus fujienensis is a dominant species.
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Xu S, Zhang S, Chen C, Yan J, Cai M, Zhu X, Gu J. Over-expression of beta-1,4-galactosyltransferase V increases the growth of astrocytoma cell line. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2002; 21:409-14. [PMID: 12385586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Our previous study showed that the gene expression of beta-1,4-galactosyltransferase V (beta-1,4-GalT V), preferentially galactosylating GlcNAc1-->6Man of oligosaccharides, increased in the process of astrocytoma progress, with the highest level in grade IV astrocytoma. To investigate the function of this beta-1,4-GalT in cell proliferation, the sense and antisense cDNA of beta-1,4-GalT V was constructed as pcDNA3-HA-GalT V and pcDNA3-anti-GalT V respectively and transfected into SHG cell, a kind of human astrocytoma cell line. The transfection was confirmed with Northern and Western blot assay. It was found that the growth of SHG/HA-GalT V in serum-containing medium was faster than that of mock-transfectant with the vector pcDNA3, whereas the growth of SHG/GalTV-AS was slower than that of mock-transfectant. GalTV-HA/SHG showed a stronger capability for colony formation than that of GalTV-AS/SHG as evaluated by anchorage-independent growth in soft agar assay. This result was consistent with that of the growth curve. By RCA-1 lectin assay, the galactosylation on the surface of GalTV-HA/SHG and SHG/GalTV-AS was stained stronger (P<0.001) and weaker (P<0.05) respectively compared with the mock transfectant. This indicates that beta-1,4-GalT V was involved in the malignant phenotype of astrocytoma cells, possibly causing the high galactosylation on the cell surface.
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Li R, Cai J, Cai M. [Synthesis and biological activities of 1-alkyl-1-benzyl-4-(3-chloro-2-hydroxy)propyl piperazinium halides]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 2002; 33:28-33. [PMID: 11938931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Seven 1-alkyl-1-benzyl-4-(3-chloro-2-hydroxy) propyl piperazinium halide hydrochloride were synthesized. Preliminary biological activity test showed that the presence of electro-attracting group in the benzyl distinctly increased the analgesic and anti-inflammatory activities of the compounds. For example, the analgesic activity of Ie and the anti-inflammatory activities of Id and Ie were all higher than those of Ia and Ib. The different anion of quaternary ammonium have some effect on the biological activity. However, this effect is not regular.
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Huang J, Cai M, Li G, Wei D, Tan Y. [Expression of HLA-I antigens in primary hepatocellular carcinoma]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 2001; 32:495-6, 504. [PMID: 12528529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To find out whether hepatocellular carcinoma (HCC) cells express HLA-I antigens. METHODS LSAB assay of immunohistochemistry was used to detect six frozen HCC specimens. RESULTS All the HCC cells have strong expression of HLA-I antigens. CONCLUSION In view of these data on the expression of HLA-I antigens, the authors deem it practical to develop HCC CTL vaccine.
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Zeng G, Yu X, Cai M. Regulation of yeast actin cytoskeleton-regulatory complex Pan1p/Sla1p/End3p by serine/threonine kinase Prk1p. Mol Biol Cell 2001; 12:3759-72. [PMID: 11739778 PMCID: PMC60753 DOI: 10.1091/mbc.12.12.3759] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2001] [Revised: 08/03/2001] [Accepted: 09/12/2001] [Indexed: 11/11/2022] Open
Abstract
The serine/threonine kinase Prk1p is known to be involved in the regulation of the actin cytoskeleton organization in budding yeast. One possible function of Prk1p is the negative regulation of Pan1p, an actin patch regulatory protein that forms a complex in vivo with at least two other proteins, Sla1p and End3p. In this report, we identified Sla1p as another substrate for Prk1p. The phosphorylation of Sla1p by Prk1p was established in vitro with the use of immunoprecipitated Prk1p and in vivo with the use of PRK1 overexpression, and was further supported by the finding that immunoprecipitated Sla1p contained PRK1- and ARK1-dependent kinase activities. Stable complex formation between Prk1p and Sla1p/Pan1p in vivo could be observed once the phosphorylation reaction was blocked by mutation in the catalytic site of Prk1p. Elevation of Prk1p activities in wild-type cells resulted in a number of deficiencies, including those in colocalization of Pan1p and Sla1p, endocytosis, and cell wall morphogenesis, likely attributable to a disintegration of the Pan1p/Sla1p/End3p complex. These results lend a strong support to the model that the phosphorylation of the Pan1p/Sla1p/End3p complex by Prk1p is one of the important mechanisms by which the organization and functions of the actin cytoskeleton are regulated.
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Braddock DT, Cai M, Baber JL, Huang Y, Clore GM. Rapid identification of medium- to large-scale interdomain motion in modular proteins using dipolar couplings. J Am Chem Soc 2001; 123:8634-5. [PMID: 11525687 DOI: 10.1021/ja016234f] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Cai M, Huang Y, Clore GM. Accurate orientation of the functional groups of asparagine and glutamine side chains using one- and two-bond dipolar couplings. J Am Chem Soc 2001; 123:8642-3. [PMID: 11525691 DOI: 10.1021/ja0164475] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zhang P, Wei D, Wang R, Zhao Z, Wang X, Cai M. [The effect of rIFN alpha-2b on mice NK cell activity]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 2001; 32:408, 429. [PMID: 12536578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE This animal experiment was made to study the effect of the recombined interferon alpha-2b(rIFN alpha-2b) on natural killer cells activity of mice spleen in vivo, and by way of this, to test the activity of rIFN alpha-2b. METHODS BALB/c mice were given rIFN alpha-2b subcutaneously. The inhibiting 3H-TdR intaking method was used to test the NK activity of spleen cells of BALB/c mice. RESULTS The NK cell activity levels of the high-dose group, the mid-dose group and the low-dose group were 65.19 +/- 17.56, 44.19 +/- 14.30 and 35.46 +/- 17.49, respectively. CONCLUSION rIFN a-2b can enhance NK cells activity observably and its effect is dose dependent.
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Cai M, Vahala K. Highly efficient hybrid fiber taper coupled microsphere laser. OPTICS LETTERS 2001; 26:884-886. [PMID: 18040480 DOI: 10.1364/ol.26.000884] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A novel hybrid fiber taper is proposed and demonstrated as the coupler in a microsphere laser system. The pump wave and the laser emission, respectively, are more efficiently coupled to and from the sphere modes with this taper structure. A 980-nm pumped erbium-ytterbium codoped phosphate microsphere laser is demonstrated in the 1550-nm band. As much as 112microW of single-frequency laser output power was measured, with a differential quantum efficiency of 12%.
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Cai M, Yu Z, Tian S. [Transporting into the kidney of medications injected into the renal adipose capsules of rats]. ZHONGHUA YI XUE ZA ZHI 2001; 81:360-3. [PMID: 11798901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To study the possibility of transporting into the renal tissue of medications by intrarenal adipose capsule injection (IC). METHODS 1. Methylene blue (MB) was injected into the renal adipose capsule of 18 male healthy SD rats, and normal saline was injected into the renal adipose capsule at the side as control. Both kidneys taken out 1 - 24 hours after the injection, frozen slices were made to observe the transport of MB. 2. Salvia miltiorrhizae (SM) was injected into both renal adipose capsule of 18 male healthy SD rats. 48 healthy male SD rats were randomly divided into two groups, Tetramethylpyrazine (20 mg) was injected into per renal adipose capsule of the rats in one group and 40 mg Tetramethylpyrazine (TP) was injected into the veins of the rats in another group. 64 SD rats were randomly divided into two groups, methylprednisolone sodium succinate (25 mg/kg) was injected into per renal adipose capsule of the rats in one group and 50 mg/kg methylprednisolone (MP) sodium succinate was injected into the veins of the rats in another group. At different time, both kidneys and blood samples of all the rats were taken out. The contents of the three medications inside renal tissue and its blood samples were individually detected by HPLC. RESULTS The peak values in the renal tissue of MB, SM, TP, MP were successively 6 h, 24 h (36 mg/g +/- 18 mg/g), 12 h (2 288 microgram/g +/- 236 microgram/g) and 1 h (120 microgram/g +/- 16 microgram/g) after IC. The medicine diffusing into the kidney can maintain longer time in IC group. CONCLUSION The renal adipose capsule can be acted as the place of medicine storing and releasing into the kidney. The medicine diffusing into the kidney can attain higher concentration and maintain longer time. IC is a feasible method of local renal ad ministration with much less side effects.
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Jiang H, Cai M. [Improved APAAP immunocytochemical staining-trace cytotoxicity test plate method for detection of cell surface antigens]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 2001; 32:143-4, 147. [PMID: 12733382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
OBJECTIVE To improve the conventional slide method of alkaline phosphatase-anti-alkaline phosphatase (APAAP) immunocytochemical staining for detection of cell surface antigens. METHODS Trace cytotoxicity test plates were utilized in the detection of CD3, CD4, CD8, CD11a, CD11b, CD18 and CD54 on lymphocytes by APAAP immunocytochemical staining. The percentages of positive cells were counted. Meanwhile, slides were used in the same objects and procedure. RESULTS The results of trace test plate method were similar to those of slide method (P > 0.05, respectively). The reproducibility was very excellent. The plate method decreased the volume of blood from 10 ml to 2 ml to detect 7 norms, and each reagent from 50 microliters to 5 microliters. CONCLUSION Trace test plate method may not only attain the result similar to that of the slide method, but also save blood and reagents; it is easy to do, so it is more suitable for clinical examination and scientific research in hospitals or institutions at the basic level.
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Kanemitsu S, Takao M, Fujinaga K, Lu J, Cai M, Gu Y, Shimamoto A, Onoda K, Shimono T, Tanaka K, Shimpo H, Yada I. [A case of surgically treated left atrial myxoma following acute multiple embolism including cerebral embolism]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 2001; 54:147-50. [PMID: 11211770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The patient was a 59-year-old female who was admitted to the hospital due to acute pain of bilateral legs, a numbness of right hand and anarthria. Angiography of extremities revealed total occlusion of right ulnar artery, left radial artery and bilateral popliteal arteries. Brain MRI revealed multiple small infarctions. Echocardiography revealed a mass in the left atrium. She was diagnosed as multiple embolism including cerebral embolism caused by left atrial myxoma. Open heart surgery immediately after the attack is generally considered contraindicated due to problems of hemorrhagic infarction or brain edema. But, relapse of embolism may deteriorate the condition and miss the timing of surgery. Thus we performed removal of left atrial myxoma 4 days after the attack. The postoperative course was uneventful. This is a few report about open heart surgery immediately after the attack. We report about the indication and the optimal timing of open heart surgery following cerebral embolism.
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Cai M, Pemberton JE. Vibrational spectroscopy of dimethylchlorooctadecylsilane covalently bonded to ultrathin silica films immobilized on Ag surfaces. FRESENIUS' JOURNAL OF ANALYTICAL CHEMISTRY 2001; 369:328-34. [PMID: 11293712 DOI: 10.1007/s002160000670] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
FTIR and Raman spectroscopies have been used to characterize the structure and conformational order of dimethylchlorooctadecylsilane (DOS) covalently bonded to ultrathin silica films supported on Ag substrates. Ultrathin silica films of ca. 30 A thickness prepared from sol-gel methods are immobilized on Ag surfaces modified with a self-assembled monolayer of (3-mercaptopropyl)trimethoxysilane (3MPT). This layered structure provides a unique opportunity for acquiring complementary spectral data from both FTIR and Raman spectroscopies, which are useful in elucidating alkylsilane conformation pertaining to stationary phases for reversed-phase liquid chromatography (RPLC). Characterization of octadecyltrichlorosilane (OTS) layers on thin silica films of ca. 800 A thickness on 3MPT-modified Ag surfaces has been reported previously. Differences between the ultrathin silica films used in this study and the thin silica films used in this previous study are considered. The results from both FTIR and Raman spectroscopy presented here suggest that bonded DOS alkyl chains are in a disordered, liquid-like state with close to monolayer surface coverage.
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Xu H, Zhang Q, Xiao X, Zhou Y, Wen L, Xu J, Cai M. Three-dimensional ultrasonography in obstetrics: the clinical value. Curr Med Sci 2001; 21:38-41, 47. [PMID: 11523244 DOI: 10.1007/bf02888033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2000] [Indexed: 11/26/2022]
Abstract
To investigate the clinical value of three-dimensional ultrasonography (3DUS) in obstetrics, various 3DUS rendering methods including surface mode, transparent mode and multiplanar mode were employed to scan 30 fetuses in second and third trimester by using the transabdominal volume transducer. The results showed that surface mode could vividly demonstrate the surface morphologic features of the fetuses, as well as the stereo-shape and the spatial relationship among the surface structures. The face, limbs, umbilical cord and outer genitalia of the fetus could be well displayed by surface mode. Transparent mode could reveal the bony structures under the surface, such as ribs, vertebrae, crania, etc. The result was not affected by the sophisticated curvature of these bony structures and the success rate was up to 100%. When rendered by multiplanar mode, the region of interest (ROI) could be viewed from different directions. It should be concluded that 3DUS could serve as a supplement to two-dimensional ultrasonography (2DUS). 3DUS might play an important role in prenatal diagnosis and enhance the diagnostic confidence level of the physicians.
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Sun C, Cai M, Meadows RP, Xu N, Gunasekera AH, Herrmann J, Wu JC, Fesik SW. NMR structure and mutagenesis of the third Bir domain of the inhibitor of apoptosis protein XIAP. J Biol Chem 2000; 275:33777-81. [PMID: 10934209 DOI: 10.1074/jbc.m006226200] [Citation(s) in RCA: 194] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The inhibitor of apoptosis proteins (IAPs) regulate the caspase family of cysteine proteases, which play an important role in the execution of programmed cell death. Human X-linked inhibitor of apoptosis protein (XIAP) is a potent inhibitor of caspases-3, -7, and -9. Here we show that the Bir3 domain is the minimal region of XIAP that is needed for potent caspase-9 inhibition. The three-dimensional structure of the Bir3 domain of XIAP, determined by NMR spectroscopy, resembles a classical zinc finger and consists of five alpha-helices, a three-stranded beta-sheet, and a zinc atom chelated to three cysteines and one histidine. The structure of the Bir3 domain is similar to that of the Bir2 domain of XIAP but differs from the previously determined structure of the Bir3 domain of MIHB. Based on site-directed mutagenesis, we have identified the regions of the Bir3 domain of XIAP that are important for inhibiting caspase-9. Despite the structural similarities of the Bir2 and Bir3 domain of XIAP, a different set of residues were found to be critical for inhibiting the individual caspases. These results suggest that XIAP inhibits caspase-3 and caspase-9 in a different manner.
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Cai M, Painter O, Vahala KJ, Sercel PC. Fiber-coupled microsphere laser. OPTICS LETTERS 2000; 25:1430-1432. [PMID: 18066238 DOI: 10.1364/ol.25.001430] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We demonstrate a 1.5-microm - wavelength fiber laser formed by placement of glass microsphere resonators along a fiber taper. The fiber taper serves the dual purpose of transporting optical pump power into the spheres and extracting the resulting laser emission. A highly doped erbium:ytterbium phosphate glass was used to form microsphere resonant cavities with large gain at 1.5microm . Laser threshold pump powers of 60muW and fiber-coupled output powers as high as 3 muW with single-mode operation were obtained. A bisphere laser system consisting of two microspheres attached to a single fiber taper is also demonstrated.
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Han FM, Cheng ZY, Cai M, Chen Y. [Separation and determination of glibenclamide in xiaotangling tablets by micellar electrokinetic capillary chromatography]. Se Pu 2000; 18:456-8. [PMID: 12541712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
A high performance capillary electrophoresis method has been developed for separation and quantitative analysis of glibenclamide in Xiaotangling tablets. Electrophoretic conditions were as follows: micellar electrokinetic capillary chromatography (MECC) mode, trimethoprimum as internal standard, uncoated fused silica capillary (34.8 cm/39.5 cm(effective/total length), 50 microns i.d.), 25 mmol/L borax-30 mmol/L SDS(pH 9.0), applied voltage 17 kV, (+)-->(-), temperature 28 degrees C, detection wavelength 228 nm, pressure injection 68.95 kPa.s. Glibenclamide was separated successfully from other components within 14 minutes under the optimum conditions, and the relative peak area of glibenclamide increased linearly with the increase of its concentration within the range of 25 mg/L-275 mg/L. The recovery was (100.6 +/- 1.4)%. The method is simple, rapid and well reproducible, and can be used as a reliable tool for the quality control of Chinese traditional medicine containing glibenclamide.
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Shi X, Fettinger JC, Cai M, Davis JT. Enantiomeric Self-Recognition: Cation-Templated Formation of Homochiral Isoguanosine Pentamers This research was sponsored by the Separations and Analysis Program, Chemical Sciences Division, Office of Basic Energy Sciences, U.S. Department of Energy. J.D. thanks the Dreyfus Foundation for a Teacher-Scholar Award. We thank Professors Giovanni Gottarelli and Steve Rokita for helpful discussions. Angew Chem Int Ed Engl 2000; 39:3124-3127. [PMID: 11028054 DOI: 10.1002/1521-3773(20000901)39:17<3124::aid-anie3124>3.0.co;2-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Cai M, Painter O, Vahala KJ. Observation of critical coupling in a fiber taper to a silica-microsphere whispering-gallery mode system. PHYSICAL REVIEW LETTERS 2000; 85:74-7. [PMID: 10991162 DOI: 10.1103/physrevlett.85.74] [Citation(s) in RCA: 252] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/1999] [Indexed: 05/22/2023]
Abstract
We present the observation of critical coupling in a high- Q fused-silica microsphere whispering-gallery mode resonator coupled to a fiber taper. Extremely efficient and controlled power transfer to high- Q ( approximately 10(7)) resonators has been demonstrated. Off-resonance scattering loss was measured to be less than 0.3%. On-resonance extinction in transmitted optical power through the fiber coupler was measured as high as 26 dB at the critical coupling point. This result opens up a range of new applications in fields as diverse as near-field sensing and quantum optics.
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Cai M, Sidorov V, Lam YF, Flowers RA, Davis JT. Guest and subunit exchange in self-assembled ionophores. Org Lett 2000; 2:1665-8. [PMID: 10880196 DOI: 10.1021/ol0058442] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] Self-assembled ionophores, formed by hydrogen bonding of isoG 1 around a cation, are dynamic structures. Multinuclear NMR spectroscopy in CD(3)CN-CDCl(3) showed that cation exchange is >10(4) faster than exchange of isoG 1 ligand in (isoG 1)(10)-Cs(+) Ph(4)B(-). The cationic guest also affected the kinetic stability of the complex. 2D-EXSY NMR experiments in CDCl(3) showed that ligand exchange was 2 orders of magnitude faster for the Li(+)-decamer than for the Cs(+)-decamer.
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Cai M, Marlow AL, Fettinger JC, Fabris D, Haverlock TJ, Moyer BA, Davis JT. Binding Cesium Ions with Nucleosides: Templated Self-Assembly of Isoguanosine Pentamers This research was supported by the Separations and Analysis Program, Division of Chemical Sciences, Office of Basic Energy Sciences, U.S. Department of Energy. J.T.D. thanks the Dreyfus Foundation for a Teacher-Scholar Award. We thank Drs. Bryan Eichhorn, Steve Rokita, and Lyle Isaacs for advice. Angew Chem Int Ed Engl 2000; 39:1283-1285. [PMID: 10767032 DOI: 10.1002/(sici)1521-3773(20000403)39:7<1283::aid-anie1283>3.0.co;2-r] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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198
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Cai M, Vahala K. Highly efficient optical power transfer to whispering-gallery modes by use of a symmetrical dual-coupling configuration. OPTICS LETTERS 2000; 25:260-262. [PMID: 18059848 DOI: 10.1364/ol.25.000260] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report that greater than 99.8% optical power transfer to whispering-gallery modes was achieved in fused-silica microspheres by use of a dual-tapered-fiber coupling method. The intrinsic cavity loss and the taper-to-sphere coupling coefficient are inferred from the experimental data. It is shown that the low intrinsic cavity loss and the symmetrical dual-coupling structure are crucial for obtaining the high coupling efficiency.
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Tang HY, Xu J, Cai M. Pan1p, End3p, and S1a1p, three yeast proteins required for normal cortical actin cytoskeleton organization, associate with each other and play essential roles in cell wall morphogenesis. Mol Cell Biol 2000; 20:12-25. [PMID: 10594004 PMCID: PMC85029 DOI: 10.1128/mcb.20.1.12-25.2000] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/1999] [Accepted: 09/28/1999] [Indexed: 11/20/2022] Open
Abstract
The EH domain proteins Pan1p and End3p of budding yeast have been known to form a complex in vivo and play important roles in organization of the actin cytoskeleton and endocytosis. In this report, we describe new findings concerning the function of the Pan1p-End3p complex. First, we found that the Pan1p-End3p complex associates with Sla1p, another protein known to be required for the assembly of cortical actin structures. Sla1p interacts with the first long repeat region of Pan1p and the N-terminal EH domain of End3p, thus leaving the Pan1p-End3p interaction, which requires the second long repeat of Pan1p and the C-terminal repeat region of End3p, undisturbed. Second, Pan1p, End3p, and Sla1p are also required for normal cell wall morphogenesis. Each of the Pan1-4, sla1Delta, and end3Delta mutants displays the abnormal cell wall morphology previously reported for the act1-1 mutant. These cell wall defects are also exhibited by wild-type cells overproducing the C-terminal region of Sla1p that is responsible for interactions with Pan1p and End3p. These results indicate that the functions of Pan1p, End3p, and Sla1p in cell wall morphogenesis may depend on the formation of a heterotrimeric complex. Interestingly, the cell wall abnormalities exhibited by these cells are independent of the actin cytoskeleton organization on the cell cortex, as they manifest despite the presence of apparently normal cortical actin cytoskeleton. Examination of several act1 mutants also supports this conclusion. These observations suggest that the Pan1p-End3p-Sla1p complex is required not only for normal actin cytoskeleton organization but also for normal cell wall morphogenesis in yeast.
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Xun L, Bohuslavek J, Cai M. Characterization of 2,6-dichloro-p-hydroquinone 1,2-dioxygenase (PcpA) of Sphingomonas chlorophenolica ATCC 39723. Biochem Biophys Res Commun 1999; 266:322-5. [PMID: 10600501 DOI: 10.1006/bbrc.1999.1805] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pentachlorophenol (PCP) is a general biocide and a major environmental pollutant. The initial steps of PCP degradation by Sphingomonas chlorophenolica ATCC 39723 have been studied and characterized. Two enzymes are responsible for converting PCP to 2, 6-dichloro-p-hydroquinone (2,6-DiCH) which is a common metabolic intermediate of the biodegradation of polychlorinated phenols. 2, 6-DiCH is degraded by PcpA from strain ATCC 39723, but the reaction end product has been misidentified as 6-chlorohydroxyquinol and has been elusive to detection. We report here the overproduction of PcpA in Escherichia coli and the demonstration of quantitative conversion of 2,6-DiCH to 2-chloromaleylacetate with the coconsumption of one equivalent O(2) and release of one equivalent Cl(-) by purified PcpA. On the basis of the reaction stoichiometry, the enzyme is proposed to be 2,6-DiCH 1,2-dioxygenase.
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