[Effect of occupationally exposed to dioxin on serum oxidative stress indices in male workers].
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Adult↗
Biomedical subjects
Peng Zhang
Publications and source records attributed to Peng Zhang.
[Preparation of nanometer TiO2 doped with upconversion luminescence agent and investigation on degradation of ethyl violet using visible light].
A novel upconversion luminescence agent 40CdF2 x 60BaF2 x 1.6Er2O3 was synthesized and the fluorescent spectrum was determined. This upconversion luminescence agent can emit five upconversion fluorescent peaks whose wavelengths are all below 387nm under the excitation of 488 nm visible light. This upconversion luminescence agent was mixed into nanometer TiO2 powder by ultrasonic dispersion and the doped nanometer TiO2 photocatalyst utilizing visible light was prepared. The doped TiO2 powder was charactered by XRD and TEM and its photocatalytic activity was checked through the photocatalytic degradation of ethyl violet dye as a model compound under the visible light irradiation emitted by three basic color lamp. Otherwise, in order to compare the photocatalytic activities the same experiment was carried out for undoped photocatalytic TiO2 powder. The degradation ratio of ethyl violet dye in the presence of doped nanometer TiO2 powder reached 99.68% under visible light irradiation at 12.0 h which was obviously higher than the corresponding degradation ratio in the presence of undoped nanometer TiO2 powder, which indicate that the upconversion luminescence agent prepared as dopant can effectively turn visible lights to ultraviolet lights which are absorbed by nanometer TiO2 particles and produce the electron-cavity pairs.
Catalysis↗
[Inducement of tumor cell autophagy and cell cycle analysis].
BACKGROUND & OBJECTIVE: Autophagy is the main phenomenon of type II programmed cell death which is also named as autophagic cell death, and autophagy has a close relationship with autophagic cell death. The relationship of apoptosis and cell cycle has been explored deeply, but little is known about the relationship of autophagic cell death and cell cycle. This study was to observe the correlation of autophagy induced by different methods to cell cycle. METHODS: Exponentially growing HeLa and SW480 cells, and peripheral blood lymphocytes (PBLs) from healthy donors, with or without 48 h stimulation of phytohemagglutinin (PHA), were treated with Hanks' solution (to produce starvation) or vincristine. Confocal laser microscope and transmission electron microscope (TEM) were used to detect autophagy; flow cytometry (FCM) was innovatively used to detect the cell cycle of autophagic cells with dipl-parameters of microtubule-associated protein 1 light chain 3 (MAP1-LC3-II)/PI. RESULTS: Autophagy of HeLa and SW480 cells induced by starvation or vincristine was observed in G1, S, and G2/M phases and increased along with the inducement time; no autophagy was observed in unstimulated PBLs. The positive rate of LC3-II, indicating the occurrence of autophagy, was lower than 2.62% when induced by starvation in Hanks' solution for 48 h, or 6.16% when induced by vincristine for 48 h. After PBLs were stimulated into cell cycle by PHA, autophagy was markedly detected 2 h after the indicated inducements. CONCLUSIONS: MAP1-LC3-II/DNA dipl-parameter analysis by FCM is a convenient and reliable method for simultaneously analyzing autophagy and cell cycle. Autophagy could be induced when cells are in cell cycle, while the cells in G0 phase are insensitive to the inducers.
Autophagy↗
A new lignan from Smilax bockii warb.
A new lignan named (-)-isolariciresinol 9'-carboxylic acid methyl ester has been isolated from the roots of Smilax bockii warb. The structure of the new lignan was determined on the basis of spectral and chemical studies.
Animals↗
[DNA damage and apoptosis of human airway epithelial cell lines caused by cigarette smoke extract].
BACKGROUND & OBJECTIVE: Cigarette smoke exposure has been reported to induce DNA damage in a variety of cell types. This study was to investigate DNA damage and apoptosis in normal human bronchial epithelial cell line NHBE and lung carcinoma cell line SPC-A1 caused by cigarette smoke extract. METHODS: NHBE and SPC-A1 cells were incubated with different concentrations of cigarette smoke extract. Cell viability was evaluated by MTT assay. Fluorescence-labeled anti-histone gamma-H2AX polyclonal antibody was used to detect DNA double-strand breaks (DSBS) in chromatin. DNA damage was analyzed by flow cytometry. The expression of gamma-H2AX was detected by Western blot. Cigarette smoke extract-induced cell apoptosis was detected by sub G1 peak method and annexin V-FITC/propidium iodide (PI) staining assay. Cell morphology of DNA damage and apoptosis was observed by confocal laser microscopy. RESULTS: MTT assay results showed that cigarette smoke extract decreased the viability of NHBE and SPC-A1 cells in time-and concentration-dependent manners. Cigarette smoke extract induced DSBS in NHBE cells and SPC-A1 cells, and led to H2AX phosphorylation (denoted gamma-H2AX) in time-and concentration-dependent manners. The maximal value of gamma-H2AX was seen about 4 h after the treatment, and the value decreased subsequently, but did not reduce to a normal level. Cell apoptosis appeared about 12 h after DNA damage. Cigarette smoke extract also initiated the accumulation of gamma-H2AX in these cells, and cell apoptosis morphology was observed 4 h later. CONCLUSION: Cigarette smoke extract can induce DSBS and apoptosis in NHBE and SPC-A1 cells in time-and concentration-dependent manners.
Adenocarcinoma↗
[Paclitaxel induces apoptosis of acute leukemia cells in S phase].
BACKGROUND & OBJECTIVE: Cell cycle specificity, an important feature of anticancer drugs, is commonly used in the design of combined chemotherapy. Paclitaxel is widely accepted as an G2/M phase-specific agent. However, cumulative evidences revealed that the cell cycle specificity of anticancer drugs in vitro is not always consistent as in vivo. This study was to observe the effect of paclitaxel on the cell cycle specificity in different cell models. METHODS: Effects of paclitaxel on cell apoptosis of human lymphocyte leukemia cell line Molt-4 and 17 clinical specimens of acute leukemia were investigated using flow cytometry. RESULTS: Paclitaxel induced G2/M phase-specific apoptosis in exponentially growing Molt-4 cells, G0/G1 phase-specific apoptosis in high-density cultured Molt-4 cells, and S phase-specific apoptosis in acute leukemia specimens. CONCLUSIONS: Paclitaxel exhibits different cell-cycle specificity in different models. Different from other studies, paclitaxel induces S phase-specific apoptosis in clinical leukemia specimens. This difference is most likely related to the growing status of the target cells.
Adolescent↗
[The role of serine endopeptidase in cucumber leaf senescence].
The role of serine endopeptidase in cucumber leaf senescence was studied by using the inhibitor of serine endopeptidase and plant growth regulators (6-BA and ABA) on darkness-induced cucumber leaves. The results showed that the senescence of cucumber leaves were delayed by AEBSF [4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride], an inhibitor of serine-type endopeptidase, or 6-BA treatment. The chlorophyll contents increased by AEBSF (Fig.3) and the protein degradation of leaves under AEBSF treatment declined more slowly than in the control or under ABA 50 micromol/L treatment (Fig.4), partly because the activities of serine endopeptidases became lower during senescence. However, the activities of endopeptidase in cucumber leaf were increased by ABA 50 micromol/L (Fig.2A), furthermore, the MDA content were also influenced by AEBSF and plant growth regulators (Fig.5). Native gradient PAGE showed that six bands of isoenzymes were detected in cucumber leaves and four bands of which were the type of serine-endopeptidase (Fig.1), and proved that the activities of serine-endopeptidase were inhibited by AEBSF, but enhanced by ABA (Fig.2B) in the leaves. It implies that serine endopeptidases might play an important role in cucumber leaf senescence.
Abscisic Acid↗
[Extraperitoneal laparoscopic radical prostatectomy (report of 5 cases)].
OBJECTIVE: To discuss the clinical experience of laparoscopic radical prostatectomy by extraperitoneal approach. METHODS: Five patients with localized prostate cancer underwent laparoscopic radical prostatectomy by extraperitoneal approach. The surgical procedure included the excision of the prostate, seminal vesicles, ampulla ductus deferentis and part of the bladder neck, followed by urethrovesical anastomosis. RESULTS: All the operations were successful. The mean operation time was 350 minutes (ranging from 270 to 420 mm); the mean estimated blood loss was 480 ml (ranging from 250 to 600 ml). The bowel activity was recovered with 48 hours after surgery. The patients were ambulant between the 2nd and 3rd postoperative days. The mean hospital stay was 8. 5 days (ranging from 7 to 12 days). The 3-8 months follow-up found no incontinence of urine; of the 3 preoperatively potent patients, 2 were able to have sexual intercourse; strictured stoma was reported in only 1 case. CONCLUSION: The extraperitoneal laparoscopic radical prostatectomy, keeping the procedure out of the peritoneal cavity, with small incision and rapid recovery, may be considered as a promising surgical method for patients with localized prostate cancer.
Aged↗
Correlation of CD105 and vascular endothelial growth factor in laser-induced choroidal neovascularization in rats.
PURPOSE: Choroidal neovascularization (CNV) plays an important role in pathogenesis of age-related macular degeneration (AMD), ocular histoplasmosis syndrome (OHS) and so on. However, mechanisms of CNV formation are not fully understood. The aim of this study is to investigate the correlation between expressions of CD105 and vascular endothelial growth factor (VEGF) in experimental laser-induced CNV in rats. METHODS: CNV model was established by 532 nm laser photocoagulation in Brown-Norway rats. The expression of CD105 and VEGF in CNV was observed by immunohistochemistry at 3, 7, 14, 21, 28 and 56 days after laser photocoagulation. The image analysis was performed with the professional software of Image-Pro Plus. RESULTS: Fluorescein angiography showed fluorescein leakage in CNV from days 7 to 56 after photocoagulation. VEGF expression was mainly observed in vascular endothelial cells, ganglion cells, inner nuclear layers and retinal pigment epithelial cells in normal retina and vascular endothelial cells in normal choroid of the rats. On day 3 after photocoagulation, VEGF began to express in laser-induced lesions. VEGF was strongly expressed in CNV after 7 days (P < 0.05) and decreased after 14 days (P > 0.05). CD105 was initially presented in CNV at 7 days and obviously expressed at 14 days after photocoagulation (P < 0.05). Four weeks later, when angiogenesis tended toward inactive status, expression of CD105 was markedly decreased (P>0.05). There was notablely direct correlation between CD105-positive-microvessel density and positively semiquantitative scoring of VEGF in the CNV (r = 0.989, P < 0.01). CONCLUSIONS: There is direct correlation between the expression of CD105 and VEGF in the laser-induced CNV in rat. It suggests that CD105 and VEGF might participate in the new blood vessel formation and promote the growth of CNV.
Animals↗
[Studies on the breeding by ion implantation and cultivation of mycophenolic acid producing strain].
Mycophenolic acid is produced by aerobic fermentation of several Penicillium species. It has a broad spectrum of activity like antitumor activity, antiviral, anti-psoriatic, immunosuppressive and anti-inflammatory activity. It also exhibits antibacterial and antifungal activities. The immunosuppressive effect of MPA has been important in treatment of organ rejection after organ transplant surgery. There is a continuous need to find improved process for efficiently obtaining superior MPA producing mutants. In recent years, the ion implantation technique has been widely applied in many fields and has been drawn morn concern. However there is no report in the field of mutational breeding of MPA producing strain. Penicillium brevicompactum M-51 was derived from MPA producing strain F-663 by varied mutational methods including U.V. and microwave irradiation. In the process of increasing the production of MPA from P. brevicompactum M-51, a mutant strain M-163 was obtained by means of N+ ion implantation. An decline-increase-decline tendency of strain survival rates was observed when the strain was implanted by N+ ion with dose from 20 2.6 x 10(13) ions/cm2 to 180 x 2.6 x 10(13) ions/cm2 under implantation energy 15 keV. It apparently appeared "saddle shape". And under the implantation dose of 140 x 2.6 x 10(13) ions/cm2, the variation rate and the positive variation rate of the strain had reached the highest values 88.9% and 63.4%, respectively. The HPLC results showed that MPA yield of P. brevicompactum M-163 was improved by 30.1%, and its productivity was rather stable through successive transfer of cultures. The effect of seed growth time on yield of MPA was studied, and the best seed age was 24h after incubation. In the mean time, the fermentative condition of M-163 was studied through orthogonal design. The major ingredients being investigated included carbon and nitrogen sources. Finally the optimized fermentation medium was obtained. The yield of MPA reached 2819g/mL in the optimized submerged fermentation progress. In conclusion, N+ ion implantation had been proven to be effective for mutational breeding of P. brevicompactum M-51. By means of N+ ion implantation and optimizing the fermentative condition, the yield of MPA was increased by 20.2 times than the wild-type stain F-663.
Fermentation↗
[The inhibition of CYP2C9 isoenzyme in Cunninghamella blakesleeana AS 3. 910].
AIM: To investigate the variation of CYP2C9 isoenzyme activity in the microbial model in response to inhibitors of CYP2C9. METHODS: Using C. blakesleeana AS 3. 910 as a model strain, the impact of CYP2C9 inhibitors on the metabolites yields of CYP2C9 substrates was determined and the drug-drug interactions among CYP2C9 substrates were evaluated. Liquid chromatography-mass spectrometry was used to analyze biotransformation products. RESULTS: Benzbromarone decreased the yield of 4'-hydroxytolbutamide from 100% to 14.5%; sulfaphenazole decreased the yield of O-demethylindomethacin from 75.2% to 9.9%; valproic acid decreased the yield of 4'-hydroxydiclofenac from 98.6% to 2.7%, separately. Tolbutamide, indomethacin and diclofenac interacted with each other, resulting in the decreased formation of metabolites catalyzed by CYP2C9. CONCLUSION: Three CYP2C9 inhibitors inhibit the activity of CYP2C9 isoenzyme in C. blakesleeana AS 3. 910 differently, and there are drug-drug interactions among CYP2C9 substrates.
Aryl Hydrocarbon Hydroxylases↗
[Expression of pituitary tumor-transforming gene in patients with multiple myeloma].
To explore the expression of pituitary tumor-transforming gene (PTTG) in elderly patients with multiple myeloma (MM) and its relationship with MM, the expressions of PTTG mRNA were detected in bone marrow mononuclear cells (BMMNC) from 33 patients with MM and 10 normal controls by using reverse transcriptase-polymerase chain reaction (RT-PCR). The results showed that the expression of PTTG mRNA in MM patients (0.3415 +/- 0.2172) was significantly higher than that in normal controls (0.0590 +/- 0.0233) (P < 0.05). It is concluded that the overexpression of oncogene PTTG may be related to genesis and progression of MM. It provided a new ideas to study the pathogenesis and gene therapy for MM patients.
Aged↗
Palmitoyl-protein thioesterase-1 deficiency mediates the activation of the unfolded protein response and neuronal apoptosis in INCL.
Numerous proteins undergo modification by palmitic acid (S-acylation) for their biological functions including signal transduction, vesicular transport and maintenance of cellular architecture. Although palmitoylation is an essential modification, these proteins must also undergo depalmitoylation for their degradation by lysosomal proteases. Palmitoyl-protein thioesterase-1 (PPT1), a lysosomal enzyme, cleaves thioester linkages in S-acylated proteins and removes palmitate residues facilitating the degradation of these proteins. Thus, inactivating mutations in the PPT1 gene cause infantile neuronal ceroid lipofuscinosis (INCL), a devastating neurodegenerative storage disorder of childhood. Although rapidly progressing brain atrophy is the most dramatic pathological manifestation of INCL, the molecular mechanism(s) remains unclear. Using PPT1-knockout (PPT1-KO) mice that mimic human INCL, we report here that the endoplasmic reticulum (ER) in the brain cells of these mice is structurally abnormal. Further, we demonstrate that the level of growth-associated protein-43 (GAP-43), a palmitoylated neuronal protein, is elevated in the brains of PPT1-KO mice. Moreover, forced expression of GAP-43 in PPT1-deficient cells results in the abnormal accumulation of this protein in the ER. Consistent with these results, we found evidence for the activation of unfolded protein response (UPR) marked by elevated levels of phosphorylated translation initiation factor, eIF2alpha, increased expression of chaperone proteins such as glucose-regulated protein-78 and activation of caspase-12, a cysteine proteinase in the ER, mediating caspase-3 activation and apoptosis. Our results, for the first time, link PPT1 deficiency with the activation of UPR, apoptosis and neurodegeneration in INCL and identify potential targets for therapeutic intervention in this uniformly fatal disease.
Animals↗
Relationship between MDR1 polymorphism and blood concentration of cyclosporine A.
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Adolescent↗
[Relationship between MDR1 gene polymorphism and blood concentration of tacrolimus in renal transplant patients].
OBJECTIVE: To investigate the relationship between MDR1 exon 21 and exon 26 polymorphism and whole blood concentration of tacrolimus (FK506) in renal transplant patients. METHODS: Blood samples were collected from 86 renal transplant patients who received FK506 peri-operationally. PCR-RELP was used to determine the MDR1 genotype. The patients were divided into 3 subgroups for every position: GG, GT, and TT in exon 21; and CC, CT, and TT in exon 26. Three, six, and twelve months after the transplantation ELISA was used to measure the whole blood concentration of FK506. The FK506 concentrations standardized by dosage and body weight (FK506 concentration per dose/kg) were compared among the 3 subgroups within the MDR1 exon 21 and exon 26 groups. RESULTS: Of the 86 patients 26 (30.2%), 35 (40.7%), and 25 (29.1%) were carriers of GG, GT, and TT in exon 21, and 26 (30.2%), 35 (40.7%), and 23 (26.8%) were carriers of CC, CT, and TT in exon 26. MDR1 exon 26 C3435T was in significant linkage disequilibrium with MDR1 exon 21 G2677T. Three, six, and twelve months after the transplantation a significant correlation between the whole blood FK506 concentration per dose/day and MDR1 exon 21 and exon 26 genotypes. For exon 21 there were significant differences among the 3 subgroups (all P < 0.01). The ratio for the patients with GG was remarkably lower than that of those with GT and TT, and the ratio with GT was also lower than the patients with TT (P < 0.05). For exon 26, there was also a significant difference among the 3 subgroups (all P < 0.01). The ratio for the patients with CC was remarkably lower than those of the patients with CT and TT, and the ratio of CT was also lower than that of TT (P < 0.05). CONCLUSIONS: The MDR1 gene polymorphism is correlated with the whole blood concentration of FK506. To obtain the similar blood concentration of FK506, the patients with GG and CC should take the drug at a higher dose than those with Ct and TT.
ATP Binding Cassette Transporter, Subfamily B↗
Efficient single-layer electroluminescent device based on a bipolar emitting boron-containing material.
A novel multifunctional 1,6-bis(2-hydroxyphenyl)pyridine boron bis(4-n-butyl-phenyl)phenyleneamine compound in which the hole-transporting (HT), electron-transporting (ET), and emitting (EM) components are integrated into a single molecule was synthesized and used as an emitting material to fabricate an efficient single-layer electroluminescent device.
Journal Article↗
[Dendritic cells reduce the number and function of CD4+CD25+ cells in cytokine-induced killer cells].
OBJECTIVE: To investigate the influence of dendritic cells (DCs) on the prevalence and function of regulatory T cells (Tregs) in cytokine induced killer (CIK) cells. METHODS: The blood samples of 20 patients with solid tumors were collected. The peripheral mononuclear cells (PBMCs) were isolated. CIK cells were added into the culture fluid without CD(4)(+)CD(25)(+)T cells (CIK-Treg(del) cells) and the culture fluid of regular PBMCs respectively, and the proliferation and cytotoxicity of the CIK cells were detected by BrdU method and with the cells of human lung carcinoma, breast carcinoma, colon carcinoma, and lymphoma as target cells respectively. CD(4)(+)CD(25)(+)T cells were added into another culture fluid of CIK-Treg(del) cells at the proportions of 20:1, 10:1, and 5:1 respectively, then the proliferation and cytotoxicity of the CIK cells were detected as described above. Flow cytometry was used to detect the surface markers of CIK cells. To identify the influence of DCs on the anti-tumor activity of CIK, PBMCs were isolated from the patients with solid tumor to culture the DCs and CIK cells. Dendritic cells were harvested on day 7 and co-cultured with the CIK cells (DC+CIK cells). The frequency of Tregs in CIK was determined by flow cytometry. The cytotoxicity was examined by LDH assay. The levels of TGF-beta, IL-10, IFN-gamma, IL-2, and IL-6 were analyzed by ELISA. RESULTS: The rates of the main effector cells in CIK cells (CD(3)(+)CD(56)(+) cells) were 17% +/- 5% and 28% +/- 5% in the regular CIK cells and CIK-Treg(del) cells respectively. LDH method showed that the cytotoxicity towards tumor cells of the CIK-Treg(del) cells The rates of the main effector cells in CIK cells (CD(3)(+)CD(56)(+) cells) were 17% +/- 5% and 28% +/- 5% in the regular CIK cells and CIK-Treg(del) cells respectively. LDH method showed that the cytotoxicity towards tumor cells of the CIK-Treg(del) cells was higher than that of the regular CIK cells (P < 0.05), however, after the addition of selected cells, the cytotoxicity of the CIK-Treg(del) cells decreased. Flow cytometry showed that the proportions of CD(4)(+)CD(25)(+) Treg cells in the CIK cells and DC-CIK cells were 13% +/- 5% and 10% +/- 4% respectively (t = 3.977, P = 0.001). After the DC induction the cytotoxicity of CIK cells was significantly higher than that of the regular CIK cells. ELISA showed that after DC induction the levels of TGF-beta and IL-10 of the DC+CIK group were significantly lower than those of the regular CIK cells (t = 2.136, P = 0.046; and t = 2.965, P = 0.008), and the level of IFN-gamma was significantly higher in the DC+CIK group (t = 2.220, P = 0.039). CONCLUSION: CD(4)(+)CD(25)(+) regulatory T cells inhibit the anti-tumor activity of CIK cells. The interaction between CIK cells and DCs is sufficient for the blockage of the properties of regulatory T cells. CIK cells have the desirable properties for immunotherapy approaches, especially after co-culture with DCs.
CD4-Positive T-Lymphocytes↗
An optical glucose biosensor based on glucose oxidase immobilized on a swim bladder membrane.
An optical glucose biosensor using a swim bladder membrane as an enzyme immobilization platform and an oxygen-sensitive membrane as an optical oxygen transducer has been developed. During the enzymatic reaction, glucose is oxidized by glucose oxidase with a concomitant consumption of dissolved oxygen resulting in an increase in the fluorescence intensity of the optical oxygen transducer. The fluorescence intensity is directly related to the glucose concentration. The effects of pH, temperature, buffer concentration, and selectivity have been studied in detail. The immobilized enzyme retained 80% of its initial activity after being kept for more than 10 months at 4 degrees C. The glucose biosensor has been successfully applied to the determination of glucose content in human blood serum and urine samples.
Air Sacs↗