Photon counting histogram for one-photon excitation.
Explore the source record for details and available documents.
Fluorescent Dyes↗
Biomedical subjects
Bo Huang
Publications and source records attributed to Bo Huang.
Free radical scavenging efficiency of Nano-Se in vitro.
In this study, we showed that smaller size particles of Nano-Se have better scavenging effects on the following free radicals: carbon-centered free radicals (R*) generated from 2,2'-azo-bis-(2-amidinopropane) hydrochloride (AAPH), the relatively stable free radical 1,1-diphenyl-2-picryhydrazyl (DPPH), the superoxide anion (O2*-) generated from the xanthine/xanthine oxidase (X/XO) system, singlet oxygen (1O2) generated by irradiated hemoporphyrin. Furthermore, the three sizes of Nano-Se studied also show protective effects against the oxidation of DNA. The three samples all have potential size-dependent characteristics on scavenging the free radicals. Although in this study we regarded Nano-Se as a whole without considering interactions between BSA and the red selenium nano-particles, there is the possibility that the apparent free radical scavenging effects may be partially contributed by such interactions.
Amidines↗
Identification of novel recognition motifs and regulatory targets for the yeast actin-regulating kinase Prk1p.
Prk1p is a serine/threonine kinase involved in the regulation of the actin cytoskeleton organization in the yeast Saccharomyces cerevisiae. Previously, we have identified LxxQxTG as the phosphorylation site of Prk1p. In this report, the recognition sequence for Prk1p is investigated more thoroughly. It is found that the presence of a hydrophobic residue at the position of P-5 is necessary for Prk1p phosphorylation and L, I, V, and M are all able to confer the phosphorylation at various efficiencies. The residue flexibility at P-2 has also been identified to include Q, N, T, and S. A homology-based three-dimensional model of the kinase domain of Prk1p provided some structural interpretations for these substrate specificities. The characterization of the [L/I/V/M]xx[Q/N/T/S]xTG motif led to the identification of a spectrum of potential targets for Prk1p from yeast genome. One of them, Scd5p, which contains three LxxTxTG motifs and is previously known to be important for endocytosis and actin organization, has been chosen to demonstrate its relationship with Prk1p. Phosphorylation of Scd5p by Prk1p at the three LxxTxTG motifs could be detected in vitro and in vivo, and deletion of PRK1 suppressed the defects in actin cytoskeleton and endocytosis in one of the scd5 mutants. These results allowed us to conclude that Scd5p is likely another regulatory target of Prk1p.
Actins↗
Human corneal endothelial cell expression of Na+,K+-adenosine triphosphatase isoforms.
OBJECTIVE: To determine the expression of alpha subunits and different isozymes of Na+,K+-adenosine triphosphatase (ATPase) in human corneal endothelial cells (HCECs). METHODS: Immunoblot and RNA analysis of Na+,K+-ATPase alpha subunit expression were performed in preparations from HCECs that had been immortalized by transformation with simian virus 40. Na+,K+-ATPase activity was determined by constructing dose-response curves for the ouabain inhibition of Na+,K+-ATPase activity in human corneal endothelial cells. RESULTS: Both messenger RNA analysis and immunoblot studies indicated that HCECs express ATPase catalytic alpha1 and alpha3, but not alpha2 and alpha4, subunits. A limited amount of alpha3 subunit was expressed in HCECs compared with the alpha1 subunit. Biochemical analyses of Na+,K+-ATPase activity revealed 2 independently active Na+,K+-ATPase isoenzymes, a low-affinity site with a kinetic parameter for ouabain inhibition constant (Ki) in the micromolar range and a high-affinity site with a constant Ki in the nanomolar range. These 2 sites may be associated with alpha1 and alpha3 isoforms, respectively, expressed in HCECs. CONCLUSIONS: Human corneal endothelial cells express alpha1 and alpha3 isoforms of Na+,K+-ATPase, and both polypeptides are catalytically competent in these cells. Defining the components of Na+,K+-ATPase in HCECs is an important step toward elucidating the mechanisms that regulate corneal endothelial ionic pump function as well as the pathogenesis of corneal diseases associated with corneal edema.
Cell Line, Transformed↗
Inhibitory effect of recombinant endostatin on angiogenesis and tumor growth of hepatoma.
To study the influence of recombinant endostatin on angiogenesis and tumor growth of mice H22 hepatoma, tumor models were constructed by injecting H22 hepatoma cells into the leg muscle of mice. Recombinant endostatin was produced by gene engineering in E. coli. The recombinant protein was injected subcutaneously to treat transplanted hepatoma faraway. The weight of tumors was measured, and the changes of necrosis of tumor cells and vessel density were observed by immunohistochemistry. The results suggested that the growth of hepatoma models transplanted in the muscle of legs was suppressed by recombinant endostatin. The density of vascularity was decreased, but the necrosis of tumor cells increased. The inhibitory effect of recombinant endostatin on angiogenesis and tumor growth of hepatoma was not affected after chemotherapy.
Angiogenesis Inhibitors↗
Update on nonexcimer laser refractive surgery technique: conductive keratoplasty.
Excimer laser-based refractive surgery techniques have been the most popular forms to correct myopia, hyperopia, and astigmatism. However, development of non-excimer based refractive surgery such as thermal techniques provides a viable alternative to laser vision correction. Earlier forms of thermal techniques showed a lack of predictability and stability, resulting in the abandonment of the further development of these techniques. Recently, conductive keratoplasty, a laserless, radiofrequency-based technique, has been approved by the FDA for the correction of low to moderate hyperopia. Preliminary data showed that conductive keratoplasty seems to be safe, effective, and showed good refractive stability. This review will discuss recent studies on conductive keratoplasty technique in terms of its efficacy, safety, refractive predictability, and stability.
Astigmatism↗
Experimental study on therapeutic effect of in vivo expression of Cell I-Hep II recombinant polypeptide of fibronectin on murine H22 hepatocellular carcinoma.
AIM: To investigate the inhibitory effect of in vivo expression of expressing plasmid pCH510 of recombinant fibronectin polypeptide (CH50) on hepatocellular carcinoma and the improved therapeutic effect of pCH510 in combination with chemotherapeutic agents and Hsp70-H22 hepatocarcinoma antigen peptide on tumor. METHODS: Mice were inoculated with H22 hepatocarcinoma cells. The chemotactic effect of the expression of plasmid pCH510 on immunocytes was observed after in vivo transfection, tissue slicing and HE staining. Inhibitory effect of transfection with pCH510 on murine tumor originated from different inoculative doses was observed. The inhibitory effect of immediate transfection with pCH510 after chemotherapy on tumor was compared with that of transfection 5 days after chemotherapy. The change of function and amount of mouse peritoneal macrophages and the peripheral blood immunocytes resulted from administration of chemotherapeutic agents were detected. The peptides mixture was prepared from H22 hepatocarcinoma cells. pCH510 + Hsp70-H22 antigen peptides were injected into tumor-bearing mice with or without chemotherapy, to observe the inhibitory effects on tumor. RESULTS: At the tumor tissue site injected with pCH510, there were a great number of immunocytes which mainly were macrophages, lymphocytes and neutrophils. Transfection of plasmid pCH510 inhibited significantly the murine tumor induced by different inoculative doses. The inhibitory effect was negatively correlated with the inoculative dose. The therapeutic effect was not improved by immediate transfection with pCH510 after chemotherapy, but was significantly improved by transfection with pCH510 5 days after chemotherapy. Chemotherapeutic agent decreased the number of immunocytes and suppressed their activation in vivo. After injection of drug, the amount of immunocytes was the lowest from d 1 to d 3 and returned to normal level on the 10(th) day. Transfection with plasmid pCH510 alone could inhibit tumor induced by the inoculation with 10(4) H22 cells. The tumor originated from the inoculation with 10(5) H22 cells was inhibited by pCH510+Hsp70-H22 antigen peptides and that from the inoculation with 10(6) H22 cells was inhibited by pCH510+Hsp70-H22 antigen peptides in combination with chemotherapeutic agents. CONCLUSION: In vivo expression of pCH510 recruits immune cells, inhibits tumor growth, and enhances the efficacy of chemotherapy. But the proper timing of combining chemotherapy with pCH510 must be taken into great account. The synergism of pCH510 and Hsp70-H22 peptides can improve the efficacy, which could be further enhanced if they are used following chemotherapy. Chemotherapeutic agent + pCH510 + Hsp70-H22 peptides is a promising therapeutic approach of combination treatment of tumor.
Animals↗
[Adriamycin or adriamycin-Fe3+ induced bovine serum albumin damage].
ESR spectroscopy was used to investigate the production of reactive oxygen radicals in adriamycin (ADM) and its iron complex. The results showed that ADM-Fe(3+) induced the production of oxygen radicals more efficiently than ADM. The damage of BSA mediated by ADM or ADM-Fe(3+) was investigated by measuring the increase of reactive carbonyl content and the decrease of the fluorescence intensity of the Trp residue. It was shown that the damage of bovine serum albumin (BSA) was dependent on the time and on the concentration of ADM or ADM-Fe(3+). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that BSA was not cross-linked nor fragmented by the effect of ADM or ADM-Fe(3+). It was also found that oxygen radical scavengers could inhibit the damage of BSA induced by ADM or ADM-Fe(3+), suggesting that ADM or ADM-Fe(3+) induced protein damage via the oxygen radicals produced in the reaction.
Animals↗
[Specific anti-tumor immunity and its cross-reaction induced by antigen peptide mixture prepared from different T lymphocytic leukaemia cell lines].
OBJECTIVE: To investigate the specific antitumor immunity induced by antigen peptide mixture prepared from different T lymphocytic leukaemia cells and the cross-reaction among the mixtures of different cell lines. METHODS: Antigen peptide mixtures were prepared from different leukaemia cell lines and then bound with Hsp70 in vitro. The activation and proliferation of peripheral blood mononuclear cell (PBMC) were observed after the stimulation by different Hsp70-peptide complexes. The cytotoxicity of such activated PBMCs to different target cells was assayed. RESULTS: The antigen peptides from different leukaemia cell lines were mixed ones, which could activate PBMC effectively with Hsp70 and stimulate the activated PBMC to proliferate. The proliferative PBMC had specific cytotoxicity to the corresponding leukaemia cells. To Hut-78 cell, Molt-4 cell and Jurkat cell, the cytotoxicity of PBMC activated by either Hut78-peptides or Molt-4-peptides was significantly stronger than that of PBMC activated by HL-60-peptides (P < 0.05). The cytotoxicity to Jurkat cell of PBMC activated by Hut78/Molt-4-peptides was significantly stronger than that of PBMC activated by Hut78-peptides or Molt-4-peptides alone (P < 0.05). CONCLUSION: Antigen peptide mixture from T lymphocytic leukaemia cells is able to induce specific antitumor immunity. There is a cross-reactivity among antigen peptide mixtures from different T lymphocytic leukaemia cell lines, with the more crossed antigen peptides obtained from the mixtures of different antigen peptides from different T lymphocytic leukaemia cell lines, which suggests that the antigen peptide mixture with broad antigenic spectrum could possibly be prepared by using multiple leukaemia cell lines.
Antigens, Neoplasm↗
[Functional characterization of recombinant myostatin and its inhibitory role to chicken muscle development].
Myostatin is a recently discovered member of transforming growth factor beta (TGFbeta) superfamily and shares similar structure features with other members of TGFbeta superfamily. For a better understanding of molecular mechanism of myostatin function, the production of C-terminal truncated form of recombinant myostatin protein (rMSTN) in E. coli was previously reported. Herein, the functional role of the recombinant myostatin in regulating myogenesis in a chicken embryonic myoblasts (CEMs) system was determined. By using flow cytometric analysis, the myostatin was found to inhibit cell cycle transition from G1 to S phase and result in a cell cycle arrest at G1. In addition, myostatin blocked the multi-nucleus myotube formation and caused a decreased expression of the muscle cell differentiation markers (myogenin and MHC) in CEMs. In this study, a rabbit polyclonal antibody against myostatin was produced and high affinity and specificity of this anti-myostatin antibody to recombinant and endogenous myostatin were assayed by Western blot analysis. Further studies showed that the antibody could also recognize the tissue endogenous myostatin of human, mouse and rat. A specific 40 kD band was detected in chicken muscle, which suggested that chicken myostatin might have different splicing pattern. Immunofluorescence assay indicated that myostatin predominantly existed in the cytosol in C2C12 cells. Taken together, the results show that myostatin inhibits chicken muscle cells proliferation and differentiation and down-regulates expression of two differentiation marker gene in CEMs. Remarkably, production of functional recombinant myostatin protein and its specific antibody provides important reagents for unraveling molecular mechanisms underlying myostatin action during myogenesis.
Animals↗
[The effects of endotoxin on the Th1/Th2 cells and immune modulation of Astragalus membranaceus].
Explore the source record for details and available documents.
Animals↗
Analysis of biomolecular interactions using a miniaturized surface plasmon resonance sensor.
A commercially available miniaturized surface plasmon resonance sensor has been investigated for its applicability to biological interaction analysis. The sensor was found to exhibit excellent repeatability and linearity for high-refractive index solutions and good reproducibility for the binding of proteins. Its detection limit for the monoclonal antibody M1 was found to be 2.1 fmol, which corresponds to a surface concentration of 21 pg/mm2. Simple surface immobilization procedures relying on biotin/avidin or glycoprotein/lectin chemistry have been explored. Equilibrium dissociation constants for the binding of the FLAG peptide to its monoclonal antibody (M1) and for the binding of concanavalin A to a glycoprotein have been determined. The close agreement of these measurements with values obtained by surface fluorescence microscopy and fluorescence correlation spectroscopy helps to validate the use of this device. Thus, this sensor shows promise as an inexpensive, portable, and accurate tool for bioanalytical applications in laboratory and clinical settings.
Animals↗
Inducement of specific CTLs by antigen-peptides from human leukemia cells and their cytotoxicity to leukemia cells.
To investigate the inducement of cytotoxic T lymphocytes (CTLs) by antigen peptides mixture from different leukemia cells and the cross-reaction of the mixtures from different cell lines, antigen peptides mixtures were prepared from different leukemia cell lines respectively and then bound with Hsp70 in vitro. Activation and proliferation of PBMC were observed after stimulation with different Hsp70-peptide complexes. The ratio of CD8+ in proliferative cells was analyzed by flow cytometry. The cytotoxicity of the activated PBMC to different target cells was assayed. The results showed that the antigen peptides from different leukemia cell lines, bound with Hsp70, could activate PBMC effectively, and stimulate the activated PBMC to proliferate. The proliferative PBMC had specific cytotoxicity to corresponding leukemia cells. CD8+ cells, accounting for a high proportion in proliferative cells, had a specific cytotoxicity to leukemia cells from which antigen peptides were prepared, suggesting that these CD8+ cells were CTLs specific to leukemia cells. CTLs activated by Hut78-peptides or Molt4-peptides had a significantly stronger cytotoxicity to Hut78 cells, Molt-1 cells and Jurkat cells than that of CTLs activated by HL-60-peptides (P < 0.05). And the cytotoxicity of CTLs activated by Hut78/Molt4-peptides to Jurkat cells was significantly stronger than that of CTLs activated by either Hut78-peptides or Molt4-peptides alone (P < 0.05). It is concluded that antigen peptides mixtures from leukemia cells can induce specific antitumor CTLs. There exists cross-reactivity among antigen peptides mixtures from different cell lines of the same type leukemia and more cross-reactive antigen peptides could be obtained from more cell lines, suggesting that antigen peptides mixture with broad antigenic spectrum could be prepared by using multiple leukemia cell lines.
Antigens, Neoplasm↗
Fluorescence emission and absorption spectra of single Anabaena sp. strain PCC7120 cells.
The fluorescence emission and absorption spectra of single Anabaena sp. strain PCC7120 cells including vegetative cells and heterocysts have been studied in intact filaments in vivo with confocal microscopy and grating spectrography. The diameters of the excitation and detection areas in the cells are less than 1.0 microm. Heterogeneities within the same cell and among different cells are observed. The evident spectral heterogeneities in heterocysts, not reported previously, are attributed to the different stages of the evolution of phycobilisomes in heterocysts. The photosystem II in heterocysts were found to be not metabolized completely.
Anabaena↗
Experimental study of in vitro buprenorphine hydrochloride transdermal permeation through hairless mouse skin.
OBJECTIVE: To investigate the in vitro transdermal permeation of buprenorphine hydrochloride gel through hairless mouse skin and the effect of permeation enhancers on the permeability of this transdermal drug delivery system. METHODS: Skin samples 1.0 cm in diameter were obtained from hairless mice for subsequent in vitro tests of the permeability of the drug. In permeation enhancer-free group, the permeability of buprenorphine hydrochloride at the concentrations of 0.5%, 1.0% and 2.0% was tested. The permeation enhancer group (all application containing 1% buprenorphine hydrochloride) was further divided into oleic group (including 3 subgroups with 2%, 4%, and 6% oleic), azone group (subdivided into 3 groups with 1%, 2%, and 4% azone) and mixed group (with 4% oleic plus 4% azone). The permeation parameters, namely steady state flux (Js) and Js enhancement ratio were evaluated. RESULTS: Js in permeation enhancer-free groups were 0.69+/-0.11, 0.90+/-0.14 and 1.18+/-0.10 microgram/cm2.h respectively, which differed only insignificantly (P>0.05). The mixed group showed the maximum permeation, with Js and ER of 13.22+/-1.27 microgram/cm2.h and 14.6 respectively. CONCLUSION: Permeation enhancers significantly increase Js of buprenorphine hydrochloride gel and renders its release kinetics approaching zero-order.
Animals↗
Tumor antigen peptides from HL-60 cells induce specific immune response.
OBJECTIVE: To prepare tumor antigen peptides from HL-60 cells and to induce specific immune response. METHODS: HL-60 antigen peptides were obtained using techniques including freezing and thawing, heat precipitation and acid precipitation. The stimulating effect of the in vitro Hsp70 binding HL-60 peptides on PBMC and the proliferation of stimulated PBMC were observed by T cell activation test. The cytotoxicity of proliferated PBMC is detected by incubating HL-60 cells or K562 cells with PBMC respectively. RESULTS: The obtained tumor antigen peptides were a peptides mixture. The mixed peptides could activate PBMC and cause PBMC proliferation in vitro after presented by Hsp70. The proliferated PBMC showed specific cytotoxicity to HL-60 cells but not to K562 cells. CONCLUSION: The method for preparing of human leukemia tumor antigen peptides used in this paper is simple and easy; the obtained antigen peptides can induce specific immune response in vitro.
Cell Division↗
[Hsp70-H22 tumor antigen peptide complex activated dendritic cell in the induction of antitumor immunity].
OBJECTIVE: To investigate the feasibility of reduction in tumor antigen peptide dose by dendritic cell (DC)-presenting so as to elucidate the characteristics of modifying DC by heat shock protein (Hsp70) and antigen peptide. METHODS: Antigen peptide bound to Hsp70 was used to modify DC in vitro. The metabolism of the modified DC and the cytokine secreted thereby was determined. Then the activation of lymphocytes by the modified DC and Hsp70-H22 peptide was tested. The cytotoxicity of the activated lymphocytes to H22 tumor cells and the inhibition of tumor in mice by DC injection and Hsp70-H22 peptide was tested. RESULTS: 0.15 micro g of H22 peptide bound to Hsp70 could mature 2 x 10(5) DC. 4 x 10(3) matured DC could activate 2 x 10(6) lymphocytes. The same amount of lymphocyte could be activated to produce similar cytotoxicity to tumor cells by either DC modified by 0.003 micro g of peptides bound with Hsp70 or by direct stimulation with 0.15 micro g of peptides bound to Hsp70. The dose of peptide could be reduced to 1/50 if the modified DC injection was used instead of direct Hsp70-peptide injection. Peptide from the normal hepatocytes, if bound to Hsp70, could not mature DC, nor could it activate lymphocytes through DC. CONCLUSION: The dose of Hsp70-H22 peptides can be reduced significantly by DC-presenting to activate lymphocytes. Peptides from normal cells, being unable to activate the lymphocytes by either Hsp70-presenting or DC-presenting, have little to offer in the induction of autoimmunity.
Animals↗
[Clinical study on modified transpalatine radical operation for carcinoma of nasopharynx].
OBJECTIVE: To evaluate the method of transpalatine surgical treatment of carcinoma of nasopharynx (NPC). METHOD: The artery palatine major was protected and the resection domain of primary lesion of NPC was expanded by modified hard palatine incision. Preventive radiotherapy and routine chemotherapy was given after the operation. RESULT: Twelve patients were in our report, five of II stage and seven of III stage. In all cases, the incisions in hard palatine were healing by first intention after the operations. The patients were followed up for six months to five years. None case was found relapse or palatal fistula. They all can swallow and speech as normal. Sequelae of radiotherapy was not found. CONCLUSION: Without affecting the healing of the incision, expanding the resective domain of primary lesion of NPC is possible by modified hard palatine incision, and the occurrence of sequelae of radiotherapy can be reduced by giving preventive radiotherapy.
Adult↗