[Objective] To investigate the effect of quercetin on the proliferation and mitochondrial transmembrane potential of CBRH-7919 cells. [Method] The CBRH-7919 cells of hepatocarcinoma were cultured in vitro. After treat...[Objective] To investigate the effect of quercetin on the proliferation and mitochondrial transmembrane potential of CBRH-7919 cells. [Method] The CBRH-7919 cells of hepatocarcinoma were cultured in vitro. After treated with different concentrations of quercetin, the OD405 nm of CBRH-7919 cells was detected by using the acid phosphatase assy (APA); morphologic changes of the cells were observed under inverted microscope; the mitochondrial transmembrane potential (△ψm) intensity changes of CBRH-7919 cells were analyzed by flow cytometry after stained with Rhodamine 123. [Result] Quercetin inhibited the proliferation of CBRH-7919 cells significantly, and the growth inhibitory effect presented time- and dose-dependent relationship. Typical decrease of cell density was observed by optical microscopy on the quercetin-treated cells. With the effect of 10 μg/ml quercetin on CBRH-7919 cells for 12, 24 and 48 h, the percentage of Rhodamine 123 stained hypofluorescence cells increased, while the mitochondrial transmembrane potential(△ψm) intensity of CBRH-7919 cells decreased. [Conclusion] Quercetin could inhibit the proliferation of CBRH-7919 cells in vitro, causing the decrease in mitochondrial transmembrane potential.展开更多
[Objective] "Tapping panel dryness (TPD)", a syndrome known as tapping incision blocked partly or entirely during latex exploiting, has become the most important factor causing great losses for rubber production. ...[Objective] "Tapping panel dryness (TPD)", a syndrome known as tapping incision blocked partly or entirely during latex exploiting, has become the most important factor causing great losses for rubber production. Aiming to elucidate the molecular mechanism of tapping panel dryness occurrence, this study carried out molecular cloning and bioinformatical analysis of a mRPL21 cDNA sequence, a gene associated with TPD. [Method] In a preliminary study, an expressed sequence tag (EST) encoding a deduced protein homologous to mitochondrial 50S ribosomal protein L21 (mRPL21), which showed to be down-regulated in the latex of TPD-affected rubber trees, was isolated by suppression subtractive hybridization (SSH). After ESTs assembling and RT-PCR validation, an 853 bp cDNA sequence with an open reading frame (ORF) was cloned, which was named as HbmRPL21 under GenBank accession number of HM230670. [Result] Bioinformatical analysis suggests that HbmRPL21 encodes a deduced polypeptide of 271 amino acids with a theoretical molecular weight (Mw) of 30.52 kDa and isolectric point (pI) of 8.40, and HbmRPL21 is a mitochondrion-targeted protein with a conserved domain of Ribosomal_L21p involving translation. Homology analysis reveals high amino acid sequence identity of mRPL21 from plants, while diversity of that between plant and animal kingdom. [Conclusion] This study laid the basis for further revealing the biological functions of mRPL21 in TPD-affected rubber trees.展开更多
Aim To assess the potential effect of quercetin (QU), an natural plant estrogen, on CYP1A2, CYP2E1, and CYP3A2 activities in rat liver microsomes; and to identify the magnitude of inhibitory effect and the probable ...Aim To assess the potential effect of quercetin (QU), an natural plant estrogen, on CYP1A2, CYP2E1, and CYP3A2 activities in rat liver microsomes; and to identify the magnitude of inhibitory effect and the probable inhibitory mechanism of QU. Methods QU and specific substrate were concurrently incubated, with HPLC detection of the substrate metabolites for data analysis. The magnitude of inhibitory effect of QU on CYP3A2 was compared with those of ketoconazole (Ket) and erythromycin (Ery). The mechanism of its inhibitory effect on CYP3A2 and CYP2E1 was derived from Lineweaver-Burk plots. Results HPLC methods were in good linear relationship with r〉0.999 1. Relative standard deviations for intra-day and inter-day were〈8.4%. Recovery of each analyte in the concentrations studied was between 91.1% and 107.6 %. QU (up to 8 μmol·L^-1) showed potent induction to CYP1A2 (338.1% of the negative control)while inhibited CYP2E1 (49.2% of the negative control) and CYP3A2 (60.3% of the negative control) activity. The magnitude of inhibitory effect for QU on CYP3A2 was between those for Ket and Ery (Ket〉QU〉Ery). QU exhibited competitive inhibition of CYP3A2 dextromethorphan N-demethylation reaction and expressed noncompetitive inhibition of CYP2E1 chlorzoxazone-6-hydroxylation reaction. Conclusion HPLC assay has been validated with precision and accuracy. QU is an effective inhibitor of several CYP isoforms. It may cause relevant drug-drug interactions with CYP3A substrates. As a plant flavonoid, QU has potential not only in molecular advantage but also in CYP450 module capability for further application in cancer chemotherapy.展开更多
Numerous theoretical and experimental efforts have been made to explain the dependence of the static wrink^h~g morphology on the materials' physical properties, whereas the dy- namic wrinkling process remains elusive...Numerous theoretical and experimental efforts have been made to explain the dependence of the static wrink^h~g morphology on the materials' physical properties, whereas the dy- namic wrinkling process remains elusive. In the present work, we design a wrinkling model consisting of a soft substrate and a graphene-like rigid thin film to investigate this dynamic process. The simulation shows that the whole wrinkling process includes three stages. At the incubation and wrinkling stages, the stress along the horizon direction of the soft substrate transfers to the stiff film. However, at the equilibrium stage, the stress of the rigid film slowly transfers back to the substrate although the total energy still decreases. It is found that the stress of the substrate concentrates at the top surface, especially at the trough, whereas the stress distribution of the film depends on direction. In the perpendicular direc- tion, the stress at the wave's equilibrium position surpasses that at the crest and trough and, oppositely, the stress concentrates at the crest and trough in the horizon direction. Present model reproduces both wrinkling and delamination patterns and can be a powerful tool to deeply understand the structure deformation of material induced by stress release.展开更多
Background The mitochondrial Na^+/Ca^2+ exchanger, NCLX, plays an important role in the balance between Ca2. influx and efflux across the mitochondrial inner membrane in endothelial ceils. Mitochondrial metabolism i...Background The mitochondrial Na^+/Ca^2+ exchanger, NCLX, plays an important role in the balance between Ca2. influx and efflux across the mitochondrial inner membrane in endothelial ceils. Mitochondrial metabolism is likely to be affected by the activity of NCLX because Ca^2+ activates several enzymes of the Krebs cycle. It is currently believed that mitochondria are not only centers of energy produc- tion but are also important sites of reactive oxygen species (ROS) generation and nucleotide-binding oligomerization domain receptor 3 (NLRP3) inflammasome activation. Methods & Results This study focused on NCLX function, in rat aortic endothelial cells (RAECs), induced by glucose. First, we detected an increase in NCLX expression in the endothelia of rats with diabetes mellitus, which was induced by an injection of streptozotocin. Next, colocalization of NCLX expression and mitochondria was detected using confocal analysis. Suppression of NCLX expression, using an siRNA construct (siNCLX), enhanced mitochondrial Ca^2+ influx and blocked efflux induced by glucose. Unexpectedly, silencing of NCLX expression induced increased ROS generation and NLRP3 inflammasome activation. Conclusions These findings suggest that NCLX affects glucose-dependent mitochondrial Ca^2+ signaling, thereby regulating ROS generation and NLRP3 in- flammasome activation in high glucose conditions. In the early stages of high glucose stimulation, NCLX expression increases to compensate in order to self-protect mitochondrial maintenance, stability, and function in endothelial cells.展开更多
AIM: To search for the biomarker of cellular immortalization, the telomere length, telomerase activity and its subunits in cultured epithelial cells of human fetal esophagus in the process of immortalization. METHODS:...AIM: To search for the biomarker of cellular immortalization, the telomere length, telomerase activity and its subunits in cultured epithelial cells of human fetal esophagus in the process of immortalization. METHODS: The transgenic cell line of human fetal esophageal epithelium (SHEE) was established with E(6)E(7) genes of human papillomavirus (HPV) type 18 in our laboratory. Morphological phenotype of cultured SHEE cells from the 6th to 30th passages, was examined by phase contrast microscopy, the telomere length was assayed by Southern blot method, and the activity of telomerase was analyzed by telomeric repeat amplification protocol (TRAP). Expressions of subunits of telomerase, hTR and hTERT, were assessed by RT-PCR. DNA content in cell cycle was detected by flow cytometry. The cell apoptosis was examined by electron microscopy (EM) and TUNEL label. RESULTS: SHEE cells from the 6th to 10th passages showed cellular proliferation with a good differentiation. From the 12th to the 16th passages, many senescent and apoptotic cells appeared, and the telomere length sharply shortened from 23kb to 17kb without expression of hTERT and telomerase activity. At the 20th passage, SHEE cells overcame the senescence and apoptosis and restored their proliferative activity with expression of telomerase and hTERT at low levels, but the telomere length shortened continuously to the lowest of 3kb. After the 30th passage cells proliferation was restored by increment of cells at S and G2M phase in the cell cycle and telomerase activity expressed at high levels and with maintenance of telomere length. CONCLUSION: At the early stage of SHEE cells, telomeres are shortened without expression of telomerase and hTERT causing cellular senescence and cell death. From the 20th to the 30th passages, the activation of telomerase and maintenance of telomere length show a progressive process for immortalization of esophageal epithelial cells. The expression of telomerase may constitute a biomarker for detection of immortalization of cells.展开更多
AIM: To explore the effects of ultrasound exposure combined with microbubble contrast agent (SonoVue) on the permeability of the cellular membrane and on the expression of plasrnid DNA encoding enhanced green fluor...AIM: To explore the effects of ultrasound exposure combined with microbubble contrast agent (SonoVue) on the permeability of the cellular membrane and on the expression of plasrnid DNA encoding enhanced green fluorescent protein (pEGFP) transfer into human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs with fluorescein isothiocyanatedextran (FD500) and HUVECs with pEGFP were exposed to continuous wave (1.9 MHz, 80.0 mW/cm^2) for 5 min, with or without a SonoVue. The percentage of FD500 taken by the HUVECs and the transient expression rate of pEGFP in the HUVECs were examined by fluorescence microscopy and flow cytornetry, respectively. RESULTS: The percentage of FDS00-positive HUVECs in the group of ultrasound exposure combined with SonoVue was significantly higher than that of the group of ultrasound exposure alone (24.0%± 5.5% vs 66.6% ± 4.1%, P 〈 0.001). Compared with the group of ultrasound exposure alone, the transfection expression rate of pEGFP in HUVECs was markedly increased with the addition of SonoVue (16.1% ± 1.9% vs 1.5% ± 0.2%, P 〈 0.001). No statistical significant difference was observed in the HUVECs survival rates between the ultrasound group with and without the addition of SonoVue (94.1% ± 2.3% vs 91.1% ± 4.1% ). CONCLUSION: The cell membrane permeability of HUVECs and the transfection efficiency of pEGFP into HUVECs exposed to ultrasound are significantly increased after addition of an ultrasound contrast agent without obvious damage to the survival of HUVECs. This non- invasive gene transfer method may be a useful tool for clinical gene therapy of hepatic tumors.展开更多
The yellow granules in the gastral cuticle of the Oriental hornet Vespa oriental& (Hymenoptera, Vespinae) are located in yellow stripes. In the present study, we focus on the micromorphology and formation of the ye...The yellow granules in the gastral cuticle of the Oriental hornet Vespa oriental& (Hymenoptera, Vespinae) are located in yellow stripes. In the present study, we focus on the micromorphology and formation of the yellow granules from their inception to their spread in the regions which are destined to acquire a yellow color, The cuticle was observed with several methods of electron microscopy. The results showed that the yellow granules comprise a layer which is 20-25 μm thick, within the total cuticular thickness of 40-45 μm. In the mentioned regions one can see, from above, many apertures of about 0.5μm in diameter which extends into a peripheral photoreceptor cell. In each yellow granule, one discerns a myoid envelope inside which there are 9 fibrils arranged in a circle. Yellow granules maturation process involves infiltration of canals that give rise to the incipient ball-shaped primary granules which increase in number (as a result of continues budding off the walls of a canal) as the cuticle matures and transform into secondary barrel shaped granules, becoming elongated and then splitting into shorter barrels that fill up the entire area. Preliminary examinations have suggested liver-like function activity within the layer of yellow granules.展开更多
Objective:The paper aimed to study the relationship between the expressions of immunoglobulin G(IgG) subclasses toward human papillomavirus 16-like particles(HPV16VLPs) in the serum of patients and different grades of...Objective:The paper aimed to study the relationship between the expressions of immunoglobulin G(IgG) subclasses toward human papillomavirus 16-like particles(HPV16VLPs) in the serum of patients and different grades of cervical lesions.Methods:The expressions of IgG subclasses in 32 cases of human papillomavirus(HPV) infection,30 cervical intraepithelial neoplasia(CIN I),43 CIN Ⅱ-Ⅲ,and 24 hysteromyoma and chronic cervicitis were examined by ELISA.Results:The absorbance values of HPV16VLPs-IgG,IgG1 increased with the grade of CIN(P < 0.05).The IgG2 dominance(IgG2/IgG1 ratio > 1) from control group was 100%,87.50% for HPV infection group,75% for CIN I group,compared with that from CIN Ⅱ-Ⅲ patients(9.52%)(P < 0.05).The positive rates and absorbance values of HPV16VLPs-IgG,IgG1 and IgG2 from HPV16-DNA positive group were significantly higher than those from non-HPV16-DNA positive group(P < 0.05).There was a moderate correlation between the HPV16-DNA testing and detection of HPV16VLPs-IgG(r = 0.531,P < 0.05).Conclusion:An increase of the expressions of HPV16VLPs-IgG and its subclasses in the serum of the patients with cervical precancerous lesions,especially those with CIN II-III,might be associated with duration of HPV infection and severity of cervical lesions.An increase of the IgG2 dominance(IgG2/IgG1 > 1) in serum from low grade cervical lesions group and normal control group,might indicate the clearance of HPV infection and the regression of cervical lesions.展开更多
Garlic peel,as the raw material,was modified by loading with zirconium(IV),exhibiting quite good uptaking behaviour for fluoride anion.The adsorption experiments were carried out in batch shaking vessels,and the proce...Garlic peel,as the raw material,was modified by loading with zirconium(IV),exhibiting quite good uptaking behaviour for fluoride anion.The adsorption experiments were carried out in batch shaking vessels,and the process was strongly dependent on the pH value.The adsorption fits Langmuir model well,and the maximum adsorption capacities at equilibrium pH 2 and 6 are evaluated to be 1.10 and 0.89 mol(fluoride)/kg of Zr-loaded garlic peel gel,respectively.The evaluation of effects of coexisting anions such as nitrate,sulfate and phosphate shows that nitrate and sulfate have no negative effect on the adsorption of fluoride,while phosphate has a little effect.Adsorption kinetics of fluoride is well described by pseudo-second-order rate equation,and the corresponding adsorption rate constant is calculated to be 3.25×10?3 g/(mg·min).展开更多
Objective To construct the zinc finger protein-activating transcription factor (ZFP-ATF) plasmid and evaluate its efficacy in inducing vascular endothelial growth factor (VEGF) expression in EY.HY926 endothelial cells...Objective To construct the zinc finger protein-activating transcription factor (ZFP-ATF) plasmid and evaluate its efficacy in inducing vascular endothelial growth factor (VEGF) expression in EY.HY926 endothelial cells. Methods Firstly, we constructed the ZFP-ATF plasmid, then testified the quantity of VEGF protein in EY.HY926 endothelial cells after transfected with ZFP-ATP plasmid by Western blot, finally, we used the RT-PCR to testify whether the ZFP-ATF can stimulate expression of VEGF splice variants. Results The ZFP-ATF DNA sequences were located the multiclone sites of PVAX1 vector between the site of BamH Ⅰ and Xhol. Western blot result showed VEGF expression in EY.HY926 endothelial cells transfected with ZFP-ATF plasmid was significantly higher than that in cells transfected with VEGF165 (19.95±3.95 vs. 12.15±1.55 μg/μL, P<0.01). RT-PCR result showed VEGF-A mRNA expression level induced by ZFP-ATF was high than that induced by VEGF165. Conclusion ZFP-ATF can up-regulate the VEGF-A expression in comparison with VEGF165, which might have beneficial effects in angiogenesis process.展开更多
Objective To assess the severity and reversibility of the chronic toxicity of a novel recombinant human granulocyte colony-stimulating factor (rhG-CSFa) in rats and the dose-effect relationship.Methods A total of 100 ...Objective To assess the severity and reversibility of the chronic toxicity of a novel recombinant human granulocyte colony-stimulating factor (rhG-CSFa) in rats and the dose-effect relationship.Methods A total of 100 Sprague-Dawley rats (equal numbers of male and female) were randomly divided into five groups (20 rats in each group):four groups were treated with rhG-CSFa at 500,100,10,1 μg/kg,respectively,and one group was treated with vehicle only to serve as the control.The rats were received subcutaneous injections of rhG-CSFa or vehicle daily for 13 weeks.During the course of the chronic toxicity study,the physical status,body weight,and food consumption were monitored.Half of the rats in each group (n=10) were sacrificed after the last rhG-CSFa administration,and the other half were sacrificed at five weeks after the last rhG-CSFa administration.Urinalyses,blood biochemistry,hematological analysis,histopathological examination,and immunological tests were performed for each of the rats.Results The hematological analyses revealed that the mean white blood cells count,neutrophils count,and neutrophils percentage were increased in male rats at the dose of 10 μg/kg or higher,and these were related with the biological activity of rhG-CSFa.Some small abnormalities were observed in the spleen of a few rats when used highest dose (500 μg/kg,a dosage of 200 folds higher than the normal clinical dosage),but these abnormalities were recovered within 5-week recovery period.No other rhG-CSFa-related abnormalities were observed in this chronic toxicity study.Conclusion No significant toxicity and immunogenicity are observed with rhG-CSFa administration to rats in the chronic toxicity studies.展开更多
Vascular endothelial cell growth inhibitor (VEGI) is a member of the tumor necrosis factor superfamily and plays an important role in vascular homeostasis. In this study, to investigate the anticancer therapeutic po...Vascular endothelial cell growth inhibitor (VEGI) is a member of the tumor necrosis factor superfamily and plays an important role in vascular homeostasis. In this study, to investigate the anticancer therapeutic potential of this gene, a secreted isoform of VEGI (VEGI-251) was inserted into a selectively replicating adenovirus with E1B 55 kDa gene deletion (ZD55) to construct ZD55-VEGI-251. We report here that secreted VEGI-251 produced from ZD55- VEGI-251-infected cancer cells potently inhibits endothelial cell proliferation, tube formation in vitro and angiogen- esis of chick chorioallantoic membrane in vivo. Additionally, ZD55-VEGI-251 infection leads to a much more severe cytopathic effect than control viruses on several human cancer cell lines, including cervical cancer cell line HeLa, hepatoma cell line SMMC-7721 and colorectal cancer cell line SW620. Further study reveals that the increased cytotoxicity is a result of VEGI-251 autocrine-dependent, mitochondria-mediated apoptosis accompanied by caspase-9 activation, enhanced caspase-3 activation and PARP cleavage. Moreover, ZD55-VEGI-251-treatment of athymic nude mice bearing human cervical and colorectal tumor xenografts markedly suppressed tumor growth. Our findings indicate that the combined effect of antiangiogenesis and apoptosis-induction activity makes the VEGI-251-armed oncolytic adenovirus a promising therapeutic agent for cancer.展开更多
Background: Ee (Eosinophilic esophagitis) is an inflammatory condition characterized by a dense eosinophilic infiltrate in the esophageal epithelium. Its pathophysiology mimics that of allergic esophagitis, and evo...Background: Ee (Eosinophilic esophagitis) is an inflammatory condition characterized by a dense eosinophilic infiltrate in the esophageal epithelium. Its pathophysiology mimics that of allergic esophagitis, and evolves clinically as a chronic disease with periods of exacerbation. Symptoms and endoscopic findings are usually non-specific and similar to those of other esophageal illnesses. The mainstay of treatment of Ee is with corticosteroids and/or specific diets, which have been shown to cause symptom remission and histological improvement. Aim: The objective of this study was to demonstrate the efficacy of a novel and promising treatment protocol for Ee. Materials and methods: We prospectively evaluated 24 patients with Ee over two years. Patients were treated with a single intramuscular injection of betamethasone sodium phosphate associated with betamethasone dipropionate and a PPI (proton pump inhibitor) (rabeprazole 20 mg PO). After 4 weeks of treatment, patients underwent endoscopy and biopsy. We evaluated patients' clinical response as well as the results of endoscopic and histological examinations. Results: After 4 weeks of treatment, all patients (100%) are reported significant clinical improvement, which was corroborated by the findings on endoscopy and histology. There were no complications or adverse reactions. Conclusions: In this cohort of patients with eosinophilic esophagitis, treatment with a single intramuscular dose of corticosteroids led to complete remission of symptoms and improvement in endoscopic and histological findings.展开更多
The integration pattern and adjacent host sequences of the inserted pMThGH-transgene in the F4 hGH-transgeniccommon carp were extensively studied. Here we show that each F4 transgenic fish contained about 200 copies o...The integration pattern and adjacent host sequences of the inserted pMThGH-transgene in the F4 hGH-transgeniccommon carp were extensively studied. Here we show that each F4 transgenic fish contained about 200 copies of thepMThGH-transgene and the transgenes were integrated into the host genome generally with concatemers in a head-to-tail arrangement at 4-5 insertion sites. By using a method of plasmid rescue, four hundred copies of transgenes fromtwo individuals of F4 transgenic fish, A and B, were recovered and clarified into 6 classes. All classes of recoveredtransgenes contained either complete or partial pMThGH sequences. The class I, which comprised 83% and 84.5%respectively of the recovered transgene copies from fish A and B, had maintained the original configuration, indicatingthat most transgenes were faithfully inherited during the four generations of reproduction. The other five classes weredifferent from the original configuration in both molecular weight and restriction map, indicating that a few transgeneshad undergone mutation, rearrangement or deletion during integration and germline transmission. In the five types ofaberrant transgenes, three flanking sequences of the host genome were analyzed. These sequences were common carpβ-actin gene, common carp DNA sequences homologous to mouse phosphoglycerate kinase-1 and human epidermalkeratin 14, respectively.展开更多
High temperature heat-treatment of wood, which is value-added green product, is one of the altematives to chemical treatment. It has better dimensional stability, thermal insulating properties and biological resistanc...High temperature heat-treatment of wood, which is value-added green product, is one of the altematives to chemical treatment. It has better dimensional stability, thermal insulating properties and biological resistance compared to kiln dried wood. It also has dark brown color which is very important for decorative purposes. Unfortunately, this color changes during weathering. Developing a transparent and non-toxic coating for the protection of heat-treated wood against discoloration without changing its natural appearance is the main objective of this study. For this purpose, waterborne acrylic polyurethane base was chosen because of its durability against weathering and non-toxic nature. Natural antioxidants which are extracted from barks and CeO2 nano particles (alone or together with lignin stabilizer) were used as additives to develop different coatings. The protective characteristics of these coatings were compared with highly pigmented and toxic industrial coating under accelerated weathering conditions. The results showed that acrylic polyurethane coatings protected wood better compared to commercially available coating tested in this study. The chemical modifications during accelerated weathering of coated and heat-treated wood surfaces were monitored by X-ray photoelectron spectroscopy analysis. The morphological changes took place during weathering were studied by fluorescence microscope analysis.展开更多
基金Supported by the Natural Science Foundation of Shandong Province(ZR2011CM021)the Science and Technology Plan of Binzhou Medical University(BY2010KJ087)~~
文摘[Objective] To investigate the effect of quercetin on the proliferation and mitochondrial transmembrane potential of CBRH-7919 cells. [Method] The CBRH-7919 cells of hepatocarcinoma were cultured in vitro. After treated with different concentrations of quercetin, the OD405 nm of CBRH-7919 cells was detected by using the acid phosphatase assy (APA); morphologic changes of the cells were observed under inverted microscope; the mitochondrial transmembrane potential (△ψm) intensity changes of CBRH-7919 cells were analyzed by flow cytometry after stained with Rhodamine 123. [Result] Quercetin inhibited the proliferation of CBRH-7919 cells significantly, and the growth inhibitory effect presented time- and dose-dependent relationship. Typical decrease of cell density was observed by optical microscopy on the quercetin-treated cells. With the effect of 10 μg/ml quercetin on CBRH-7919 cells for 12, 24 and 48 h, the percentage of Rhodamine 123 stained hypofluorescence cells increased, while the mitochondrial transmembrane potential(△ψm) intensity of CBRH-7919 cells decreased. [Conclusion] Quercetin could inhibit the proliferation of CBRH-7919 cells in vitro, causing the decrease in mitochondrial transmembrane potential.
基金Supported by the Fundamental Research Funds for Rubber Research Institute, CATAS (1630022011014)Key Science and Technology Project of Hainan Province (90107)+1 种基金Basic Scientific Research Operational Fund for Central-level Public-interest Research Institutes (YWFZX2010-9)Special Fund for Science and Technology Research of Public Welfare Trades ( nyhyzx07-033-1)~~
文摘[Objective] "Tapping panel dryness (TPD)", a syndrome known as tapping incision blocked partly or entirely during latex exploiting, has become the most important factor causing great losses for rubber production. Aiming to elucidate the molecular mechanism of tapping panel dryness occurrence, this study carried out molecular cloning and bioinformatical analysis of a mRPL21 cDNA sequence, a gene associated with TPD. [Method] In a preliminary study, an expressed sequence tag (EST) encoding a deduced protein homologous to mitochondrial 50S ribosomal protein L21 (mRPL21), which showed to be down-regulated in the latex of TPD-affected rubber trees, was isolated by suppression subtractive hybridization (SSH). After ESTs assembling and RT-PCR validation, an 853 bp cDNA sequence with an open reading frame (ORF) was cloned, which was named as HbmRPL21 under GenBank accession number of HM230670. [Result] Bioinformatical analysis suggests that HbmRPL21 encodes a deduced polypeptide of 271 amino acids with a theoretical molecular weight (Mw) of 30.52 kDa and isolectric point (pI) of 8.40, and HbmRPL21 is a mitochondrion-targeted protein with a conserved domain of Ribosomal_L21p involving translation. Homology analysis reveals high amino acid sequence identity of mRPL21 from plants, while diversity of that between plant and animal kingdom. [Conclusion] This study laid the basis for further revealing the biological functions of mRPL21 in TPD-affected rubber trees.
文摘Aim To assess the potential effect of quercetin (QU), an natural plant estrogen, on CYP1A2, CYP2E1, and CYP3A2 activities in rat liver microsomes; and to identify the magnitude of inhibitory effect and the probable inhibitory mechanism of QU. Methods QU and specific substrate were concurrently incubated, with HPLC detection of the substrate metabolites for data analysis. The magnitude of inhibitory effect of QU on CYP3A2 was compared with those of ketoconazole (Ket) and erythromycin (Ery). The mechanism of its inhibitory effect on CYP3A2 and CYP2E1 was derived from Lineweaver-Burk plots. Results HPLC methods were in good linear relationship with r〉0.999 1. Relative standard deviations for intra-day and inter-day were〈8.4%. Recovery of each analyte in the concentrations studied was between 91.1% and 107.6 %. QU (up to 8 μmol·L^-1) showed potent induction to CYP1A2 (338.1% of the negative control)while inhibited CYP2E1 (49.2% of the negative control) and CYP3A2 (60.3% of the negative control) activity. The magnitude of inhibitory effect for QU on CYP3A2 was between those for Ket and Ery (Ket〉QU〉Ery). QU exhibited competitive inhibition of CYP3A2 dextromethorphan N-demethylation reaction and expressed noncompetitive inhibition of CYP2E1 chlorzoxazone-6-hydroxylation reaction. Conclusion HPLC assay has been validated with precision and accuracy. QU is an effective inhibitor of several CYP isoforms. It may cause relevant drug-drug interactions with CYP3A substrates. As a plant flavonoid, QU has potential not only in molecular advantage but also in CYP450 module capability for further application in cancer chemotherapy.
基金the High Performance Computing Center of Tianjin University, China and the National Natural Science Foundation of China (No.91127046, No.21274107, and No.21474075).
文摘Numerous theoretical and experimental efforts have been made to explain the dependence of the static wrink^h~g morphology on the materials' physical properties, whereas the dy- namic wrinkling process remains elusive. In the present work, we design a wrinkling model consisting of a soft substrate and a graphene-like rigid thin film to investigate this dynamic process. The simulation shows that the whole wrinkling process includes three stages. At the incubation and wrinkling stages, the stress along the horizon direction of the soft substrate transfers to the stiff film. However, at the equilibrium stage, the stress of the rigid film slowly transfers back to the substrate although the total energy still decreases. It is found that the stress of the substrate concentrates at the top surface, especially at the trough, whereas the stress distribution of the film depends on direction. In the perpendicular direc- tion, the stress at the wave's equilibrium position surpasses that at the crest and trough and, oppositely, the stress concentrates at the crest and trough in the horizon direction. Present model reproduces both wrinkling and delamination patterns and can be a powerful tool to deeply understand the structure deformation of material induced by stress release.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 81173625, 81373458) Thanks for the kind help of Dr. Wang (Pulmonary Division, Boston Children's Hospital, MA, USA), who was extremely helpful in the revision of the language.
文摘Background The mitochondrial Na^+/Ca^2+ exchanger, NCLX, plays an important role in the balance between Ca2. influx and efflux across the mitochondrial inner membrane in endothelial ceils. Mitochondrial metabolism is likely to be affected by the activity of NCLX because Ca^2+ activates several enzymes of the Krebs cycle. It is currently believed that mitochondria are not only centers of energy produc- tion but are also important sites of reactive oxygen species (ROS) generation and nucleotide-binding oligomerization domain receptor 3 (NLRP3) inflammasome activation. Methods & Results This study focused on NCLX function, in rat aortic endothelial cells (RAECs), induced by glucose. First, we detected an increase in NCLX expression in the endothelia of rats with diabetes mellitus, which was induced by an injection of streptozotocin. Next, colocalization of NCLX expression and mitochondria was detected using confocal analysis. Suppression of NCLX expression, using an siRNA construct (siNCLX), enhanced mitochondrial Ca^2+ influx and blocked efflux induced by glucose. Unexpectedly, silencing of NCLX expression induced increased ROS generation and NLRP3 inflammasome activation. Conclusions These findings suggest that NCLX affects glucose-dependent mitochondrial Ca^2+ signaling, thereby regulating ROS generation and NLRP3 in- flammasome activation in high glucose conditions. In the early stages of high glucose stimulation, NCLX expression increases to compensate in order to self-protect mitochondrial maintenance, stability, and function in endothelial cells.
基金the National Natural Science Foundation of Chines,No.39830380
文摘AIM: To search for the biomarker of cellular immortalization, the telomere length, telomerase activity and its subunits in cultured epithelial cells of human fetal esophagus in the process of immortalization. METHODS: The transgenic cell line of human fetal esophageal epithelium (SHEE) was established with E(6)E(7) genes of human papillomavirus (HPV) type 18 in our laboratory. Morphological phenotype of cultured SHEE cells from the 6th to 30th passages, was examined by phase contrast microscopy, the telomere length was assayed by Southern blot method, and the activity of telomerase was analyzed by telomeric repeat amplification protocol (TRAP). Expressions of subunits of telomerase, hTR and hTERT, were assessed by RT-PCR. DNA content in cell cycle was detected by flow cytometry. The cell apoptosis was examined by electron microscopy (EM) and TUNEL label. RESULTS: SHEE cells from the 6th to 10th passages showed cellular proliferation with a good differentiation. From the 12th to the 16th passages, many senescent and apoptotic cells appeared, and the telomere length sharply shortened from 23kb to 17kb without expression of hTERT and telomerase activity. At the 20th passage, SHEE cells overcame the senescence and apoptosis and restored their proliferative activity with expression of telomerase and hTERT at low levels, but the telomere length shortened continuously to the lowest of 3kb. After the 30th passage cells proliferation was restored by increment of cells at S and G2M phase in the cell cycle and telomerase activity expressed at high levels and with maintenance of telomere length. CONCLUSION: At the early stage of SHEE cells, telomeres are shortened without expression of telomerase and hTERT causing cellular senescence and cell death. From the 20th to the 30th passages, the activation of telomerase and maintenance of telomere length show a progressive process for immortalization of esophageal epithelial cells. The expression of telomerase may constitute a biomarker for detection of immortalization of cells.
基金Supported by grants from the Nationl Natural Scientific Foundation of China, No.30300082, 30470467, and Scientific Foundation Committee of Guangdong Province, China, No.04009360
文摘AIM: To explore the effects of ultrasound exposure combined with microbubble contrast agent (SonoVue) on the permeability of the cellular membrane and on the expression of plasrnid DNA encoding enhanced green fluorescent protein (pEGFP) transfer into human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs with fluorescein isothiocyanatedextran (FD500) and HUVECs with pEGFP were exposed to continuous wave (1.9 MHz, 80.0 mW/cm^2) for 5 min, with or without a SonoVue. The percentage of FD500 taken by the HUVECs and the transient expression rate of pEGFP in the HUVECs were examined by fluorescence microscopy and flow cytornetry, respectively. RESULTS: The percentage of FDS00-positive HUVECs in the group of ultrasound exposure combined with SonoVue was significantly higher than that of the group of ultrasound exposure alone (24.0%± 5.5% vs 66.6% ± 4.1%, P 〈 0.001). Compared with the group of ultrasound exposure alone, the transfection expression rate of pEGFP in HUVECs was markedly increased with the addition of SonoVue (16.1% ± 1.9% vs 1.5% ± 0.2%, P 〈 0.001). No statistical significant difference was observed in the HUVECs survival rates between the ultrasound group with and without the addition of SonoVue (94.1% ± 2.3% vs 91.1% ± 4.1% ). CONCLUSION: The cell membrane permeability of HUVECs and the transfection efficiency of pEGFP into HUVECs exposed to ultrasound are significantly increased after addition of an ultrasound contrast agent without obvious damage to the survival of HUVECs. This non- invasive gene transfer method may be a useful tool for clinical gene therapy of hepatic tumors.
文摘The yellow granules in the gastral cuticle of the Oriental hornet Vespa oriental& (Hymenoptera, Vespinae) are located in yellow stripes. In the present study, we focus on the micromorphology and formation of the yellow granules from their inception to their spread in the regions which are destined to acquire a yellow color, The cuticle was observed with several methods of electron microscopy. The results showed that the yellow granules comprise a layer which is 20-25 μm thick, within the total cuticular thickness of 40-45 μm. In the mentioned regions one can see, from above, many apertures of about 0.5μm in diameter which extends into a peripheral photoreceptor cell. In each yellow granule, one discerns a myoid envelope inside which there are 9 fibrils arranged in a circle. Yellow granules maturation process involves infiltration of canals that give rise to the incipient ball-shaped primary granules which increase in number (as a result of continues budding off the walls of a canal) as the cuticle matures and transform into secondary barrel shaped granules, becoming elongated and then splitting into shorter barrels that fill up the entire area. Preliminary examinations have suggested liver-like function activity within the layer of yellow granules.
文摘Objective:The paper aimed to study the relationship between the expressions of immunoglobulin G(IgG) subclasses toward human papillomavirus 16-like particles(HPV16VLPs) in the serum of patients and different grades of cervical lesions.Methods:The expressions of IgG subclasses in 32 cases of human papillomavirus(HPV) infection,30 cervical intraepithelial neoplasia(CIN I),43 CIN Ⅱ-Ⅲ,and 24 hysteromyoma and chronic cervicitis were examined by ELISA.Results:The absorbance values of HPV16VLPs-IgG,IgG1 increased with the grade of CIN(P < 0.05).The IgG2 dominance(IgG2/IgG1 ratio > 1) from control group was 100%,87.50% for HPV infection group,75% for CIN I group,compared with that from CIN Ⅱ-Ⅲ patients(9.52%)(P < 0.05).The positive rates and absorbance values of HPV16VLPs-IgG,IgG1 and IgG2 from HPV16-DNA positive group were significantly higher than those from non-HPV16-DNA positive group(P < 0.05).There was a moderate correlation between the HPV16-DNA testing and detection of HPV16VLPs-IgG(r = 0.531,P < 0.05).Conclusion:An increase of the expressions of HPV16VLPs-IgG and its subclasses in the serum of the patients with cervical precancerous lesions,especially those with CIN II-III,might be associated with duration of HPV infection and severity of cervical lesions.An increase of the IgG2 dominance(IgG2/IgG1 > 1) in serum from low grade cervical lesions group and normal control group,might indicate the clearance of HPV infection and the regression of cervical lesions.
基金Project(11140065) supported by Research Program for Returned Oversea Scholars of China
文摘Garlic peel,as the raw material,was modified by loading with zirconium(IV),exhibiting quite good uptaking behaviour for fluoride anion.The adsorption experiments were carried out in batch shaking vessels,and the process was strongly dependent on the pH value.The adsorption fits Langmuir model well,and the maximum adsorption capacities at equilibrium pH 2 and 6 are evaluated to be 1.10 and 0.89 mol(fluoride)/kg of Zr-loaded garlic peel gel,respectively.The evaluation of effects of coexisting anions such as nitrate,sulfate and phosphate shows that nitrate and sulfate have no negative effect on the adsorption of fluoride,while phosphate has a little effect.Adsorption kinetics of fluoride is well described by pseudo-second-order rate equation,and the corresponding adsorption rate constant is calculated to be 3.25×10?3 g/(mg·min).
基金Supported by the National Natural Science Foundation of China(81270399and81100226)
文摘Objective To construct the zinc finger protein-activating transcription factor (ZFP-ATF) plasmid and evaluate its efficacy in inducing vascular endothelial growth factor (VEGF) expression in EY.HY926 endothelial cells. Methods Firstly, we constructed the ZFP-ATF plasmid, then testified the quantity of VEGF protein in EY.HY926 endothelial cells after transfected with ZFP-ATP plasmid by Western blot, finally, we used the RT-PCR to testify whether the ZFP-ATF can stimulate expression of VEGF splice variants. Results The ZFP-ATF DNA sequences were located the multiclone sites of PVAX1 vector between the site of BamH Ⅰ and Xhol. Western blot result showed VEGF expression in EY.HY926 endothelial cells transfected with ZFP-ATF plasmid was significantly higher than that in cells transfected with VEGF165 (19.95±3.95 vs. 12.15±1.55 μg/μL, P<0.01). RT-PCR result showed VEGF-A mRNA expression level induced by ZFP-ATF was high than that induced by VEGF165. Conclusion ZFP-ATF can up-regulate the VEGF-A expression in comparison with VEGF165, which might have beneficial effects in angiogenesis process.
基金Supported by State Scientific Key Projects for New Drug Research and Development (2009ZX09102-250)High-tech Research Project for Medicine and Pharmacology of Jiangsu Province (BG20070605)
文摘Objective To assess the severity and reversibility of the chronic toxicity of a novel recombinant human granulocyte colony-stimulating factor (rhG-CSFa) in rats and the dose-effect relationship.Methods A total of 100 Sprague-Dawley rats (equal numbers of male and female) were randomly divided into five groups (20 rats in each group):four groups were treated with rhG-CSFa at 500,100,10,1 μg/kg,respectively,and one group was treated with vehicle only to serve as the control.The rats were received subcutaneous injections of rhG-CSFa or vehicle daily for 13 weeks.During the course of the chronic toxicity study,the physical status,body weight,and food consumption were monitored.Half of the rats in each group (n=10) were sacrificed after the last rhG-CSFa administration,and the other half were sacrificed at five weeks after the last rhG-CSFa administration.Urinalyses,blood biochemistry,hematological analysis,histopathological examination,and immunological tests were performed for each of the rats.Results The hematological analyses revealed that the mean white blood cells count,neutrophils count,and neutrophils percentage were increased in male rats at the dose of 10 μg/kg or higher,and these were related with the biological activity of rhG-CSFa.Some small abnormalities were observed in the spleen of a few rats when used highest dose (500 μg/kg,a dosage of 200 folds higher than the normal clinical dosage),but these abnormalities were recovered within 5-week recovery period.No other rhG-CSFa-related abnormalities were observed in this chronic toxicity study.Conclusion No significant toxicity and immunogenicity are observed with rhG-CSFa administration to rats in the chronic toxicity studies.
基金We thank Lanying Sun, Yang Xiao, Yuelei Chen, Hua Zhou and Cell Analysis Center (Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences) for professional technical assistance. This work was supported in part by grants from Hi-Tech Research Development Program of China (863 Program, No. 2007AA021006) the Key Project of the Chinese Academy of Sciences (No. KSCX2-YW- R-09)+1 种基金 the 973 Project (No. 2004CB518804) Grant 30623003 from National Nature Science Foundation of China and Grant 06DZ22032 from Science and Technology Commission of Shang- hai Municipality.
文摘Vascular endothelial cell growth inhibitor (VEGI) is a member of the tumor necrosis factor superfamily and plays an important role in vascular homeostasis. In this study, to investigate the anticancer therapeutic potential of this gene, a secreted isoform of VEGI (VEGI-251) was inserted into a selectively replicating adenovirus with E1B 55 kDa gene deletion (ZD55) to construct ZD55-VEGI-251. We report here that secreted VEGI-251 produced from ZD55- VEGI-251-infected cancer cells potently inhibits endothelial cell proliferation, tube formation in vitro and angiogen- esis of chick chorioallantoic membrane in vivo. Additionally, ZD55-VEGI-251 infection leads to a much more severe cytopathic effect than control viruses on several human cancer cell lines, including cervical cancer cell line HeLa, hepatoma cell line SMMC-7721 and colorectal cancer cell line SW620. Further study reveals that the increased cytotoxicity is a result of VEGI-251 autocrine-dependent, mitochondria-mediated apoptosis accompanied by caspase-9 activation, enhanced caspase-3 activation and PARP cleavage. Moreover, ZD55-VEGI-251-treatment of athymic nude mice bearing human cervical and colorectal tumor xenografts markedly suppressed tumor growth. Our findings indicate that the combined effect of antiangiogenesis and apoptosis-induction activity makes the VEGI-251-armed oncolytic adenovirus a promising therapeutic agent for cancer.
文摘Background: Ee (Eosinophilic esophagitis) is an inflammatory condition characterized by a dense eosinophilic infiltrate in the esophageal epithelium. Its pathophysiology mimics that of allergic esophagitis, and evolves clinically as a chronic disease with periods of exacerbation. Symptoms and endoscopic findings are usually non-specific and similar to those of other esophageal illnesses. The mainstay of treatment of Ee is with corticosteroids and/or specific diets, which have been shown to cause symptom remission and histological improvement. Aim: The objective of this study was to demonstrate the efficacy of a novel and promising treatment protocol for Ee. Materials and methods: We prospectively evaluated 24 patients with Ee over two years. Patients were treated with a single intramuscular injection of betamethasone sodium phosphate associated with betamethasone dipropionate and a PPI (proton pump inhibitor) (rabeprazole 20 mg PO). After 4 weeks of treatment, patients underwent endoscopy and biopsy. We evaluated patients' clinical response as well as the results of endoscopic and histological examinations. Results: After 4 weeks of treatment, all patients (100%) are reported significant clinical improvement, which was corroborated by the findings on endoscopy and histology. There were no complications or adverse reactions. Conclusions: In this cohort of patients with eosinophilic esophagitis, treatment with a single intramuscular dose of corticosteroids led to complete remission of symptoms and improvement in endoscopic and histological findings.
基金supported bythe Major State Basic Research Development Program ofChina (No. 2004CB117406 and G2000016109)the National Natural Science Foundation of China (No.90208024 and 39823003).
文摘The integration pattern and adjacent host sequences of the inserted pMThGH-transgene in the F4 hGH-transgeniccommon carp were extensively studied. Here we show that each F4 transgenic fish contained about 200 copies of thepMThGH-transgene and the transgenes were integrated into the host genome generally with concatemers in a head-to-tail arrangement at 4-5 insertion sites. By using a method of plasmid rescue, four hundred copies of transgenes fromtwo individuals of F4 transgenic fish, A and B, were recovered and clarified into 6 classes. All classes of recoveredtransgenes contained either complete or partial pMThGH sequences. The class I, which comprised 83% and 84.5%respectively of the recovered transgene copies from fish A and B, had maintained the original configuration, indicatingthat most transgenes were faithfully inherited during the four generations of reproduction. The other five classes weredifferent from the original configuration in both molecular weight and restriction map, indicating that a few transgeneshad undergone mutation, rearrangement or deletion during integration and germline transmission. In the five types ofaberrant transgenes, three flanking sequences of the host genome were analyzed. These sequences were common carpβ-actin gene, common carp DNA sequences homologous to mouse phosphoglycerate kinase-1 and human epidermalkeratin 14, respectively.
文摘High temperature heat-treatment of wood, which is value-added green product, is one of the altematives to chemical treatment. It has better dimensional stability, thermal insulating properties and biological resistance compared to kiln dried wood. It also has dark brown color which is very important for decorative purposes. Unfortunately, this color changes during weathering. Developing a transparent and non-toxic coating for the protection of heat-treated wood against discoloration without changing its natural appearance is the main objective of this study. For this purpose, waterborne acrylic polyurethane base was chosen because of its durability against weathering and non-toxic nature. Natural antioxidants which are extracted from barks and CeO2 nano particles (alone or together with lignin stabilizer) were used as additives to develop different coatings. The protective characteristics of these coatings were compared with highly pigmented and toxic industrial coating under accelerated weathering conditions. The results showed that acrylic polyurethane coatings protected wood better compared to commercially available coating tested in this study. The chemical modifications during accelerated weathering of coated and heat-treated wood surfaces were monitored by X-ray photoelectron spectroscopy analysis. The morphological changes took place during weathering were studied by fluorescence microscope analysis.