Shici Tan

South China Normal University, Shengcheng, Guangdong, China

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Publications (20)9.68 Total impact

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    ABSTRACT: The mutation of tumor suppressor p53 gene is common in malignant tumor. p53 antibodies are products of immunoresponse against abnormal p53 protein. It has been found that p53 antibodies are of importance in tumor's diagnosis, prognosis and relapse monitoring. However, current method for detecting p53 antibodies, i.e. enzyme-linked immunosorbent assay (ELISA), requires a long time with multiple steps, and the assay is only semi-quantitative. In this work, a protocol for quantitative detection of p53 antibodies in human serum using immunomagnetic electrochemiluminescence (IM-ECL) was devoloped. The immunoassay format consisted of a three antibody sandwich in which a biotinylated capture antibody, was banded with the commercial p53 protein. A detector antibody was added to bind the p53 protein at another site. Then, secondary antibody, labeled with ruthenium(II) tris-bipyridal, was added and, when bound to the bead immunocompiex, generated light in the presence of an excess of tripropylamine. The light was detected and measured by the analyzer made by us. Our experimental results indicate that the sensitivity of this assay was 10 pg of p53 antibodies per ml of reference serum (normal human serum). A stable calibration curve with a wide dynamic range was established. The calibration curve was linear from 0.01 to 1000 ng/ml, thus, making quantitation possible. An immunologic prozone effect was observed above 1000 ng p53 antibodies per milliliter of serum. Serum samples from lung and nasopharyngeal carcinoma patients were tested using the IM-ECL assay. The positive rate of p53 antibodies were 28.6% in lung carcinoma and 8.33% in nasopharyngeal carcinoma, respectively. p53 antibody concentration in the carcerous human sera were quantified from the calibration curve. In the case of lung carcinoma, a trend was found that a higher p53 antibody concentration in the serum was likely linked to a higher stage of the cancer. This trend was not found in nasopharyngeal carcinoma. The assay uses only 50 microl of sample per test and requires a 30-min incubation period in addition to a 50 s acquisition time. This assay has several advantages over the commonly used ELISA method in terms of sensitivity, linear range, and assay time. Results of the study suggest that IM-ECL is a feasible method for rapid and sensitive detection of p53 antibodies in human serum.
    Journal of Immunological Methods 06/2004; 288(1-2):47-54. · 2.23 Impact Factor
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    ABSTRACT: Ultra-weak bio-chemiluminescence (UBC) from germinating soybean (Glycine max L. Merr) cotyledon under mechanical wounding was observed using a high-sensitivity imaging system based on an ICCD detector and a highly sensitive single photon counter (SPC) device. The UBC imaging showed that the intensity at the injury location on a wounded cotyledon was obviously enhanced as compared with that at the non-injured point. The UBC intensity of wounded cotyledons was initially very high and reached a stationary state after about 5 min. Wounding-induced emission could be suppressed by wounding in the presence of sodium azide. Deuterium oxide amplified the emission intensity. It was concluded that singlet oxygen ((1)O(2)) was the main cause of the emission during the wounding phase.
    Luminescence 01/2003; 18(1):37-41. · 1.27 Impact Factor
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    ABSTRACT: In this paper, sonoluminescence of tissues is reported for the first time. A sonoluminescence image of a living animal was obtained with a high-sensitivity imaging system. Furthermore, to enhance biological sonoluminescence, fluoresceinyl Cypridina luminescent analogue (FCLA), a chemiluminescence analysis agent, was used in the experiment. With the assistance of FCLA we succeeded in observing an image of a living animal with high contrast and good signal-to-noise ratio. This technique has potential applications in clinical diagnosis.
    Physics in Medicine and Biology 06/2002; 47(9):1535-41. · 2.70 Impact Factor
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    ABSTRACT: In this study, by chemiluminescence method using a Cypridina luciferin analog, 2-methyl-6-(p-methoxyphenyl)-3,7- dihydroimidazo[1,2-a]pyrazin-3-one (MCLA), as a selective and sensitive chemiluminescence probe, singlet oxygen (1O2) formation was observed in the vit C- LDL-Cu2+ reaction system. Another experimental evidence for the generation of 1O2 was the quenching effect of sodium azide (NaN3) on vit C-induced chemiluminescence in the reaction mixture of LDL- Cu2+-MCLA. Analysis based on the experimental results indicated the plausible reaction mechanism is that vit C converts Cu2+ to its reduced state and vit C becomes vit C radical itself, thereby stimulating the formation of peroxyl radicals, and bimolecular reaction of peroxyl radicals results in 1O2 production in the above systems.
    Proc SPIE 04/2002;
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    ABSTRACT: In this work, we have designed an electrochemiluminescence (ECL) reaction system used to indicate P53 protein from human lung cancer cells. And we optimized the working electrode firstly in this experiment. The electrochemiluminescence magnetic immunoassay is quantitative, reproducible, and requires only minimal sample processing. A single photon counter was used to heighten the ECL detection limit. The homologous immunoassay format consisted of a double antibody sandwich in which a biotinylated capture antibody, pre-bound to streptavidin- coated magnetic beads, was used to bind antigen from test samples. A detector antibody, labeled with ruthenium (II) tris-bipyridal chelate, was added and, when bounded to the bead immunocomplex, light was generated in the presence of excess of tripropylamine. The light was detected and measured by the ECL reaction system we designed. High- sensitive, rapid and reproducible detection of tumor marker P53 protein was actualize with this detection system. The results showed that the electrode with many holes on it can enhance the ECL efficiency, so the detection limit of the system can be improved to 1/1000 fmol/L free labels Ru(bpy)32+. Ru(bpy)32+ + TPA(tripropylmine) ECL reaction system was used to indicate P53 protein from human lung cancer cells. This method could have potential applications in early-stage tumor diagnosis and environmental inspection.
    Proc SPIE 01/2002;
  • Chaoyang Xu, Shici Tan, Da Xing
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    ABSTRACT: Low level He-Ne laser irradiation (e.g., intravascular laser irradiation on blood, ILIB) has been widely used to treat some illness clinically. One of the action processing is by improving immunocompetence of the body, but the mechanism is still not clear. In this paper, we used mouse macrophages as study object for real-time observation of the concentration change of intracellular free calcium (abb. as [Ca2+]i) of macrophages and the distribution of the Ca2+ using LSCM (laser scanning confocal microscope) after irradiation with different dose low level He-Ne laser (the actual irradiation power (abb. as P) is 0.16 mw and the facular diameter (abb. as D) is 0.5 cm. We found interesting phenomena through the image of [Ca2+]i of macrophages. The distribution of Ca2+ in macrophages has no obvious change when the time of irradiation (abb. as Ti) is 10 min. The [Ca2+]i shows obvious increase and a concentrate phenomena in Ca2+ distribution appears when Ti reach 20 min. The change of the distribution of Ca2+ become more distinct: [Ca2+]i increase more visibly and the distribution of Ca2+ shows a spacial grads when Ti reach 30 min.
    Proc SPIE 01/2002;
  • Chaoyang Xu, Da Xing, Shici Tan, Xian Li
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    ABSTRACT: Low-intensity He-Ne laser therapy (eg: intravascular laser irradiation on blood, ILIB) has been wildly used to treat with some illness in clinic, but the mechanism remains obscure. Laser power, the irradiation time and the irradiation dose were changed. Laser scanning confocal microscope (LSCM) was used to real-time research the effect of low-intensity laser irradiation on [Ca2+]i in mouse macrophages, and single photon counter device (SPC) was used to detect MCLA enhanced chemiluminescence of macrophages irradiated with low-intensity He-Ne laser. Proper dose of low-intensity He-Ne laser irradiation can increase the [Ca2+]i of the macrophages and immunocompetence of macrophages effectively. Unsuitable dose of low-intensity He-Ne laser irradiation will not increase or even decrease the [Ca2+]i and immunocompetence of the macrophages. Laser power of 0.16mw is more effect to increase the [Ca2+]i than laser power of 0.40mw. The [Ca2+]i is markedly different even the irradiation dose or the irradiation time is the same. Both the irradiation dose and laser power are key factors for the change of [Ca2+]i and immunocompetence of macrophages. Activating immuno-system of body is one of the very important mechanisms of Low-intensity He-Ne laser therapy.
    Proc SPIE 01/2002;
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    ABSTRACT: Electrochemiluminescence (ECL) technique for bimolecular detection offers ultra-high sensitivity and good signal-to- noise ratio. In this work, an ECL reaction and detection system were established. We used a big working electrode and a single photon counter to heighten the detection limit. The results showed that the detection limit of the system is 1/1000 fmol/L free labeled Ru(bpy)32+. The concentration dependence of ECL intensity was not linear in the range of low concentration (fmol/L level) free labeled Ru(bpy)32+. While in pmol/L level, the ECL intensity was linear. Ru(bpy)32+ + TPA (tripropylmine) ECL reaction system was used to indicate P53 protein from human SWO-38 cell line, which was established from grade 1-11 glioma tumor. This method could have potential applications in early-stage tumor diagnosis and environmental inspection.
    Proc SPIE 01/2002;
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    ABSTRACT: In this paper, a sonoluminescence (SL) image of living bodies were obtained with a high-sensitive imaging system for the first time. We found that some kind of chemiluminescent analytic agent, such as FCLA (Fluoresceinyl Cypridina Luminescent Analog) which can work in vivo, could enhance the SL by chemiluminescence through a chemical reaction with oxygen free radicals. In the experiment FCLA is used to enhance the biological SL of mouse body and a clear image of FCLA-enhanced SL was observed in vivo. The biological SL of several typical biological tissues are also investigated. The SL intensity from different tissues has significant difference. With confocal scanning technique, this SL imaging method has potential applications in clinical diagnosis.
    Proc SPIE 11/2000;
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    ABSTRACT: In this paper, we propose, for the first time, the concept of Sono-Dynamic Diagnosis (SDD). The novel method named FCLA Assisted Sono-Dynamic Diagnosis is designed as follows: HpD is used to localize the cancer tissue, and is sonosensitized by the ultrasound field to produce singlet oxygen. Then, another reagent, FCLA (Fluoresceinyl Cypridina Luminescent Analog), reacts with O2 to efficiently transform the chemical energy of O2 to photons, thus a strong chemiluminescence is emitted. One can then detect this emission with a high sensitive CCD imaging system to localize the tumor. Based on the principle of FCLA assisted SDD, we obtained a clear diagnostic image of a transplanted tumor in a nude mouse in the experiments. It is shown that the emission from the tumor region is much stronger than that from other regions. The outline of the tumor is quite clear. This method could have potential applications in clinics for early-stage tumor diagnosis.
    Proc SPIE 11/2000;
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    ABSTRACT: Sonoluminescence (SL) images of living bodies were obtained by a luminescence enhancement method with a high-sensitive back-illuminated CCD system. We found that the rare-gas- contained (prepared) PBS or some nonpoisonous chemiluminescent analytic agent could enhance the SL by chemiluminescence through a reaction with free radicals, and can be used for in vivo experiments. Based on ultrasound could sensitize HpD to produce the oxygen free radicals, a novel method for early-stage cancer diagnosis named as Sono- Dynamic Diagnosis was proposed. By use of sonosensitization to produce tumor-selective oxygen radicals, a clear diagnostic image of FCLA (Fluoresceinyl Cypridina Luminescent Analog)-enhanced sono-pumped chemiluminescence from tumor region is obtained. Finally, a confocal scanning technique was developed for the sonoluminescence tomography imaging for the first time. The spatial resolution was largely improved to about 100 micro with the ultrasonic intensity less than the safety limit of FDA. With the components-labeling and confocal techniques, the SL imaging method has potential applications in clinical diagnosis.
    Proc SPIE 10/2000;
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    ABSTRACT: In this paper, biological sonoluminescence (SL) of different tissues was investigated for the first time. Tissue samples (muscle, liver and fat) were prepared and put into a column- shaped ultrasound field. A photomultiplier tube and a back- illuminated cooled CCD were used to detect the SL signal. In the experiments, FCLA (Fluoresceinyl Cypridina Luminescent Analog) was used to enhance SL. With the chemiluminescence technique, we suggest that the biological SL mainly come from the free radicals produced by the ultrasound cavitation, which is different from the mechanism of the SL in aqueous solutions.
    Proc SPIE 10/2000;
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    ABSTRACT: With a high sensitivity ultraweak bioluminescence imaging system, we have obtained the emission spectra of ultraweak bioluminescence from Chinese cabbage leaf and isolated chloroplasts during the period 20 - 85 s after the cessation of illumination. Emission spectra demonstrate that chloroplast is the main origin of ultraweak bioluminescence from leaf. We suggest that the emission of leaf may be related to charge recombination in reaction center of photosystem II and deexcitation of antenna pigments.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
    09/1999;
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    ABSTRACT: Conventional Photo-Dynamic Diagnosis has several serious limitations, such as autofluorescence disturbance, poor penetration ability of the exciting laser etc. All these problems are because the exciting laser wavelength at the main absorption peak of the photosensitizer (e.g. HpD) is too short. But to our knowledge, long wavelength He-Ne laser can sensitize appropriate sensitizer to produce singlet oxygen (1O2) without autofluorescence of the normal tissues. The 1O2 can react with FCLA (5-Fluoresceinyl Cypridina Luminescent Analog) to emit chemiluminescence at the peak wavelength 532 nm, thus we can use a high sensitivity detector to image the emission from FCLA to make a localization of the cancer. This is a novel idea proposed by our group, and its feasibility was proved by our experiments.
    Proc SPIE 09/1999;
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    ABSTRACT: With a high sensitivity ultraweak bioluminescence imaging system, we have obtained the emission spectra of ultraweak bioluminescence from Chinese cabbage leaf and isolated chloroplasts during the period 20 - 85 s after the cessation of illumination. Emission spectra demonstrate that chloroplast is the main origin of ultraweak bioluminescence from leaf. We suggest that the emission of leaf may be related to charge recombination in reaction center of photosystem II and deexcitation of antenna pigments.
    Proc SPIE 09/1999;
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    ABSTRACT: Biophoton emission from germinating soybean under adverse circumstance has been observed by high sensitive imaging system based on ICCD detector. It is found that the intensity of biophoton emission from the injured position of the cotyledon is enhanced obviously compared with the intact position. In addition, a strong biophoton emission has been detected at the tip of the root when the root is supplied with water after drought. The emission induced by wounding may be associated with the defense response of plants. The emission during the process of convalescence after drought may be the results of the changes of oxidative metabolism in cells. Keywordsultra-weak luminescence-wounding-biophoton emission-defense response-active oxygen
    Chinese Science Bulletin 01/1999; 44(23):2159-2162. · 1.37 Impact Factor
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    ABSTRACT: In this paper, we report, for the first time, sonoluminescence (SL) images of living body (nude mouse) injected with and without chemical agents under weak ultrasound field. We found FCLA (Fluoresceinyl Cypridina Luminescent Analog), a chemiluminescent analytic agent, could enhance SL and can work in vivo. We also makes use of sonosensitization to produce tumor-selective oxygen radicals that can react with FCLA to emit chemiluminescence. By detecting this luminescence, we obtained a clear diagnostic image. This novel method proposed by our group has potential application in clinics for tumor early-stage diagnosis.
    Proc SPIE 01/1999;
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    ABSTRACT: No clear image of Ultraweak Biophoton Emission (UBE) from animal has been reported so far. With the detection system equipped with a back-illuminated cooled CCD (-60 degree(s)C), we have clearly observed UBE images of the wound tissues and the tumor tissues with long exposure time. The intensity of UBE from the wound tissue or the tumor tissue is higher than that from normal tissues. We proposed that the increase of UBE from wound response is the result from defense mechanism of body in which white blood cells' respiration burst is involved, the UBE from transplanted cancer tissue is related to the disorder of metabolism because of the malignant growth and multiplication of tumor cells. Non- invasive diagnosis might be realized in medicine by this technique following the further improvement of sensitivity of the detector.
    Proc SPIE 01/1999;
  • Da Xing, Qi Wang, Shici Tan, K. Ueda
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    ABSTRACT: Amplified spontaneous emissions (ASEs) of the Na<sub>2</sub> violet, K<sub>2</sub> yellow, and Rb<sub>2</sub> orange diffuse bands, which are potentially important in the development of continuously tunable high-power laser sources, were observed from electron-beam-excited mixtures of Na-Na<sub>2</sub>, K-K<sub>2</sub>, or Rb-Rb<sub>2</sub> vapor with argon buffer gas. The continuum spectra centered at 436, 574, and 604 nm were attributed to triplet-triplet Na <sub>2</sub>, K<sub>2</sub>, and Rb<sub>2</sub> bound-free transitions, respectively. The dissociative recombination reaction of Na<sub>3</sub> <sup>+</sup>, K<sub>3</sub><sup>+</sup> or Rb<sub>3</sub><sup>+</sup> is discussed as an efficient formation process of the upper states in the present electron beam pumping experiments
    IEEE Journal of Quantum Electronics 10/1998; · 2.11 Impact Factor
  • Da Xing, Shici Tan
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    ABSTRACT: Bound-free vacuum uv emissions were observed from electron- beam-pumped gas mixtures of Xe or Kr with hot alkali vapors. The observed four emission bands were assigned to the 21(Sigma) + yields 1 1(Sigma) + or 11(Pi) yields 11(Sigma) + transitions of the Xe+Cs, Kr+Cs, Xe+Li, and Kr+Li ionic excimers.
    Proc SPIE 01/1998;