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1.
The dense granule protein 4 (GRA4) is a granular protein from Toxoplasma gondii, and is a candidate for vaccination against this parasite. In this study, the plasmid pcDNA3. 1-GRA4 (pGRA4), encoding for the GRA4 antigen, was incorporated by the dehydration-rehydration method into liposomes composed of 16 mmol/L egg phosphatidylcholine (PC), 8 mmol/L dioleoyl phosphatidylethanolamine (DOPE), and 4 mmol/L 1,2-diodeoyl-3-(trimethylammonium) propane (DOTAP). C57BL/6 mice and BALB/c mice were immunized intramuscularly three times with liposome-encapsulated pGRA4 to determine whether DNA immunization could elicit a protective immune response to T. gondii. Enzyme-linked immunosorbent assay (ELISA) of sera from immunized mice showed that liposome-encapsulated pGRA4 generated high levels of IgG antibodies to GRA4. Production of primary interferon (IFN)-γ and interleukin (IL)-2 in GRA4-stimulated splenocytes from vaccinated mice suggested a modulated Th1-type response. 72.7% of C57BL/6 mice immunized with liposome-encapsulated pGRA4 survived the challenge with 80 tissue cysts of ME49 strain, whereas C57BL/6 mice immunized with pGRA4 had only a survival rate of 54.5%. When immunized BALB/c mice were intraperitoneally challenged with 103 tachyzoites of the highly virulent RH strain, the survival time of mice immunized with liposome-encapsulated pGRA4 was markedly longer than that of other groups. Our observations show that liposome-encapsulated pGRA4 enhanced the protective effect against infection of T. gondii.  相似文献   

2.
β-glucanase was purified from a solid-state culture ofTrichoderma reesei on wheat bran in three steps which comprised ammonium sulfate precipitation, Sephadex G-100 chromatography, and DEAE-Sephadex A-50 chromatography. The molecular mass was determined to be 35.21 kilodaltons by sodium dodecyl sulfate-12.5% polyacrylamide gel electrophoresis. The β-glucanase at low pHs was more stable than that at high pHs, and optimum pH was 5.0. The optimum temperature was 60°C, and β-glucanase was relatively stable at below 40°C for 60 min. TheK m of the enzyme on β-glucan was 10.86 mg/ml, and theV max on β-glucan was 14286 μmol of glucose equivalents per mg of the pure enzyme per min. The β-glucanase activity was significantly inhibited by Fe3+ ions, and was reduced in the presence of Cu2+ ions, Mn2+ ions and Mg2+ ions at 5 mmol/L and 10 mmol/L, respectively. The β-glucanase activity was stimulated by Co2+ ions, Ca2+ ions, Zn2+ ions, and Fe2+ ions at 1 mmol/L and 5 mmol/L, respectively. Project supported by Foundation for University Key Teacher of the State Ministry of Education, the National Natural Science Foundation of China (No. 30000118) and Zhejiang Provincial Natural Science Foundation of China (No. 399409).  相似文献   

3.
INTRODUCTION Costimulatory signals play a vital role in T cell activation. B7/CD28 and CD40/CD40L have been well-established as important costimulatory pathways, with the blockade of either resulting in suppression or anergy of T cells associated with prolongation of graft survival (Akalin et al., 1996; Bolling et al., 1996; Kita et al., 1999; Reddy et al., 2001; Laumonier et al., 2003; Thiel et al., 2005). Cytotoxic T lymphocyte associated antigen-4 (CTLA4), a ligand for B7, de-…  相似文献   

4.
Objective  To investigate the enhancive effect of N,N′-dinitrosopiperazine (DNP) on induced carcinogenesis in nasal and/or nasopharyngeal epithelia among TgN(p53mt-LMP1)/HT transgenic mice to examine the underlying mechanism for the development of nasopharyngeal carcinoma (NPC). Methods  TgN(p53mt-LMP1)/HT transgenic mice and the same strain of C57BL/6J wild-type mice both at the age of 5 months were randomly divided into 2 groups in parallel, respectively, i.e., TgN(p53mt-LMP1)/HT cancerous lesion-inducing group (TI), TgN(p53mt-LMP1)/HT control group (TC), C57BL/6J cancerous lesion-inducing group (CI), and C57BL/6J control group (CC). TI and CI mice were treated only with DNP for 16 weeks, twice each week, while TC and CC mice were given the same volume of saline as controls. At the end of treatment, animals were sacrificed to collect epithelial tissue samples from nasal cavity and nasopharynx for pathohistological evaluation by haematoxylin and eosin (HE) staining and for determination on the expression of TRAF2, c-Jun, and p16 by immunohistochemistry. Results  Atypical hyperplasia was more significant in the samples of TI than in those of TC, CI, and CC, with the rates of lesions being 90%, 10%, 0, and 0 (P<0.01) respectively, though DNP was used alone in a much shortened inducing period at less dosage and without the use of carcinogenic promoter 12-O-tetradecanoylphorbol-13-acetate as usual. The expressions of tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) and c-Jun in these samples were significantly up-regulated in TI (P<0.01), while the expression of p16 was significantly lower in TI than in the other groups (P<0.01). Conclusion  TgN(p53mt-LMP1)/HT mice hold inherited constitutional defect in immune surveillance function, which can be aggravated by environmental carcinogens, such as DNP used even though in a much less strength. The enhanced carcinogenesis-inducing effect of DNP on TgN(p53mt-LMP1)/HT mice should be closely associated with abnormal signaling of activator protein-1 (AP-1) pathway, especially up-regulated expressions of TRAF2 and c-Jun, and down-regulated expression of p16. Project supported by the National Natural Science Foundation of China (Nos. 30672738, 30572455 and 30572408), Hunan Provincial Natural Science Foundation for Distinguished Young Scholars (No. 03JJY1006) and for General Projects (Nos. 05JJ40029 and 07JJ6038), the Research Foundation of Hunan Provincial Scientific and Technological Department for International Cooperative Academic Projects (No. 06WK3016), and the Research Foundation of Hunan Provincial Education Department for Outstanding Young Scholars (No. 06B070), China  相似文献   

5.
Lipophilic tea polyphenols (LTP) were prepared by catalytic esterification of green tea polyphenols (GTP) with hexadecanoyl chloride. A novel long-chain acyl-derivative of epigallocatechin-3-o-gallate (EGCG) was first isolated from purification of LTP by high-speed countercurrent chromatography (HSCCC) using a solvent system composed of n-hexane-ethyl acetate-methanol-water (1∶1∶1∶1, v/v). The molecular structure of the acyl-derivative, Epigallocatechin-3-O-gallate-4′-O-hexadecanate, was elucidated by means of elemental analysis, IR,1H-NMR and MS spectra. Project (No. 200010) supported by Zhejiang Provincial Natural Science Foundation, China  相似文献   

6.
The long-arm and short-arm genes of fibroin light chain (L-chain) of silkworm,Bombyx Mori L., and the gene of human acidic fibroblast growth factor were cloned respectively and subsequently inserted into a transfer vector pVL 1392 used as a tool to target the L-chain region of the silkworm genome. Genomic DNA from their offsprings was extracted and the expected targeting was detected using polymerase chain reaction and DNA sequencing, as well as protein analysis. The results showed that positive events occurred and that the FGF gene was integrated into the L-chain locus through homologous recombination. Project supported by the Scientific Research Foundation for Returned Overseas Chinese Scholars, Education Ministry of China and the Natural Science Foundation of Zhejiang Province (No. 301306), China  相似文献   

7.
Burrows dug by house mice in laboratory burrow boxes were examined in two inbred strains (C57BL/6J and BALB/cJ) across five age groups and compared with burrows of wild trapped mice. Burrows of feral domestic mice were examined in an outdoor enclosure as well as in the laboratory. Results demonstrated that burrows differ between strains; highly active C57 mice tended to burrow more than did Balbs at all age ranges. Moreover, burrows became more complex with age in both strains. Differences among domestic, feral, and wild mice were minimal. Results are discussed in terms of possible genetic differences in activity and as evidence against the notions of degeneracy accompanying domestication.  相似文献   

8.
INTRODUCTION Enzymes are efficient and specific biocatalysts widely used in food industries, but their application in industrial process often involves special properties not found in natural source enzymes. In order to ob- tain desirable enzymes, in the past ten years, scientists have developed rational (Kurth et al., 1998; Mouratou et al., 1999; DeSantis et al., 1999) and irrational de- sign methods (Babbitt and Gerlt, 1997; O’Brien and Herschlag, 1999) to improve the enzyme propert…  相似文献   

9.
Waste hops are good sources of flavonoids. Extraction of flavonoids from waste hops (SC-CO2 extracted hops) using supercritical fluids technology was investigated. Various temperatures, pressures and concentrations of ethanol (modifier) and the ratio (w/w) of solvent to material were tested in this study. The results of single factor and orthogonal experiments showed that at 50°C, 25 MPa, the ratio of solvent to material (50%), ethanol concentration (80%) resulted in maximum extraction yield flavonoids (7.8 mg/g). HPLC-MS analysis of the extracts indicated that flavonoids obtained were xanthohumol, the principal prenylflavonoid in hops. Project (No. Y304203) supported by the Natural Science Foundation of Zhejiang Province, China  相似文献   

10.
Objective: To study the stereoselective glucuronidation of carvedilol (CARV) by three Chinese liver microsomes. Methods: The metabolites of CARV were identified by a hydrolysis reaction with β-glucuronidase and HPLC-MS/MS. The enzyme kinetics for CARV enantiomers glucuronidation was determined by a reversed phase-high pressure liquid chromatogra-phy (RP-HPLC) assay using (S)-propafenone as internal standard after precolumn derivatization with 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosylisothiocyanate. Results: Two CARV glucuronides were found in three Chinese liver microsomes incubated with CARV. The non-linear regression analysis showed that the values of Km and Vmax for (S)-CARV and (R)-CARV enantiomers were (118±44) μmol/L, (2 500±833) pmol/(min·mg protein) and (24±7) μmol/L, (953±399) pmol/(min·mg protein), respectively. Conclusion: These results suggested that there was a significant (P<0.05) stereoselective glucuronidation of CARV enantiomers in three Chinese liver microsomes, which might partly explain the enantioselective pharmacokinetics of CARV.  相似文献   

11.
Background: Sevoflurane and propofol are effective cardioprotective anaesthetic agents, though the cardioprotection of propofol has not been shown in humans. Their roles and underlying mechanisms in anesthetic postconditioning are unclear.Mitochondrial permeability transition pore (MPTP) opening is a major cause of ischemia-reperfusion injury. Here we investigated sevoflurane- and propofol-induced postconditioning and their relationship with MPTP. Methods: Isolated perfused rat hearts were exposed to 40 min of ischemia followed by 1 h of reperfusion. During the first 15 min of reperfusion, hearts were treated with either control buffer (CTRL group) or buffer containing 20 μmol/L atractyloside (ATR group), 3% (v/v) sevoflurane (SPC group),50 μmol/L propofol (PPC group), or the combination of atractyloside with respective anesthetics (SPC ATR and PPC ATR groups). Infarct size was determined by dividing the total necrotic area of the left ventricle by the total left ventricular slice area (percent necrotic area). Results: Hearts treated with sevoflurane or propofol showed significantly better recovery of coronary flow,end-diastolic pressures, left ventricular developed pressure and derivatives compared with controls. Sevoflurane resulted in more protective alteration of hemodynamics at most time point of reperfusion than propofol. These improvements were paralleled with the reduction of lactate dehydrogenase release and the decrease of infarct size (SPC vs CTRL: (17.48±2.70)% vs (48.47±6.03)%,P＜0.05; PPC vs CTRL: (35.60±2.10)% vs (48.47±6.03)%, P＜0.05). SPC group had less infarct size than PPC group (SPC vs PPC:(17.48±2.70)% vs (35.60±2.10)%, P＜0.05). Atractyloside coadministration attenuated or completely blocked the cardioprotective effect of postconditioning of sevoflurane and propofol. Conclusion: Postconditioning of sevoflurane and propofol has cardioprotective effect against ischemia-reperfusion injury of heart, which is associated with inhibition of MPTP opening. Compared to propofol, sevoflurane provides superior protection of functional recovery and infarct size.  相似文献   

12.
Study of the SISO mixedH 2/l1 problem for discrete time systems showed that there exists a unique optimal solution which can be approximated within any prescribed missing error bound inl 2 norm with solvable suboptimal solutions and solvable superoptimal solutions. Project supported by the National Natural Science Foundation of China (No. 60174026) and the Scientific Research Foundation for Returned Overseas Chinese Scholars of Zhejiang Province (No. J20020546)  相似文献   

13.
Phytoremediation is emerging as a potential cost-effective solution for remediation of contaminated soils, and bioavailability of metal in the soil for plant uptake is an important factor for successful phytoremediation. This study aimed at investigating the ability of EDTA and citric acid for enhancing soil bioavailability of Cu and phytoremediation by Elsholtzia splendens in two types of soils contaminated with heavy metals [i.e. mined soil from copper mining area (MS), and paddy soil (PS) polluted by copper refining]. The results showed that addition of 2.5 mmol/kg EDTA significantly increased the H2O extractable Cu concentration from 1.20 to 15.78 mg/kg in MS and from 0.26 to 15.72 mg/kg in PS, and that shoot Cu concentration increased 4-fold and 8-fold as compared to the control. There was no significant difference between the treatment with 5.0 mmol/kg EDTA and that with 2.5 mmol/kg EDTA, probably because that 2.5 mmol/kg EDTA was enough for elevating Cu bioavailability to the maximum level. As compared with the control, citric acid had no marked effect on both soil extractable Cu and shoot Cu concentration or accumulation. The results indicated that EDTA addition can increase the potential and efficiency of Cu phytoextraction byE. splendens in polluted soils. Project supported by the National Natural Science Foundation of China (No. 29977017) and the Science and Technology Ministry of China (No. 2002CB410804)  相似文献   

14.
Spinal muscular atrophy (SMA) is a disorder characterized by degeneration of lower motor neurons and occasionally bulbar motor neurons leading to progressive limb and trunk paralysis as well as muscular atrophy. Three types of SMA are recognized depending on the age of onset, the maximum muscular activity achieved, and survivorship: SMA1, SMA2, and SMA3. The survival of motor neuron (SMN) gene has been identified as an SMA determining gene, whereas the neuronal apoptosis inhibitory protein (NAIP) gene is considered to be a modifying factor of the severity of SMA. The main objective of this study was to analyze the deletion of SMN1 and NAIP genes in southern Chinese children with SMA. Here, polymerase chain reaction (PCR) combined with restriction fragment length polymorphism (RFLP) was performed to detect the deletion of both exon 7 and exon 8 of SMN1 and exon 5 of NAIP in 62 southern Chinese children with strongly suspected clinical symptoms of SMA. All the 32 SMA1 patients and 76% (13/17) of SMA2 patients showed homozygous deletions for exon 7 and exon 8, and all the 13 SMA3 patients showed single deletion of SMN1 exon 7 along with 24% (4/17) of SMA2 patients. Eleven out of 32 (34%) SMA1 patients showed NAIP deletion, and none of SMA2 and SMA3 patients was found to have NAIP deletion. The findings of homozygous deletions of exon 7 and/or exon 8 of SMN1 gene confirmed the diagnosis of SMA, and suggested that the deletion of SMN1 exon 7 is a major cause of SMA in southern Chinese children, and that the NAIP gene may be a modifying factor for disease severity of SMA1. The molecular diagnosis system based on PCR-RFLP analysis can conveniently be applied in the clinical testing, genetic counseling, prenatal diagnosis and preimplantation genetic diagnosis of SMA. Project supported by the National Natural Science Foundation of China (No. J0710043), and the Natural Science Foundation of Zhejiang Province (No. 2007C33049), China  相似文献   

15.
Fusarium head blight (FHB) caused byFusarium graminearum is a devastating disease that results in extensive yield losses to wheat and barley. A green fluorescent protein (GFP) expressing plasmid pRP22-GFP was constructed for monitoring the colonization of two biocontrol agents,Brevibacillus brevis ZJY-116, on the spikes of barley and their effect on suppression of FHB. Survival and colonization of theBrevibacillus brevis ZJY-1 andBacillus subtilis ZJY-116 strains on spikes of barley were observed by tracking the bacterial transformants with GFP expression. Our field study revealed that plasmid pRP22-GFP was stably maintained in the bacterial strains without selective pressure. The retrieved GFP-tagged strains showed that the bacterial population fluctuation accorded with that of the rain events. Furthermore, both biocontrol strains gave significant protection against FHB on spikes of barley in fields. The greater suppression of barley FHB disease was resulted from the treatment of barley spikes with biocontrol agents before inoculation withF. graminearum. Project supported by the National Natural Science Foundation of China (No. 30230250) and Science and Technology Committee of Zhejiang Province (No. 2003C22029), China  相似文献   

16.
The increasingly serious problem of acid rain is leading to increased potassium (K) loss from soils, and in our field investigation, we found that even congenerically relative Mosla species show different tolerance to K-deficiency. A hydroponic study was conducted on the growth of two Mosla species and their morphological, physiological and stoichiometric traits in response to limited (0.35 mmol K/L), normal (3.25 mmol K/L) and excessive (6.50 mmol K/L) K concentrations. Mosla hangchowensis is an endangered plant, whereas Mosla dianthera a widespread weed. In the case of M. hangchowensis, in comparison with normal K concentration, K-limitation induced a significant reduction in net photosynthetic rate (P n), soluble protein content, and superoxide dismutase (SOD) activity, but an increase in malondialdehyde (MDA) concentration. However, leaf mass ratio (LMR) and root mass ratio (RMR) were changed little by K-limitation. In contrast, for M. dianthera, K-limitation had little effect on P n, soluble protein content, SOD activity, and MDA concentration, but increased LMR and RMR. Critical values of N (nitrogen): K and K:P (phosphorus) ratios in the shoots indicated that limitation in acquiring K occurred under K-limited conditions for M. hangchowensis but not for M. dianthera. We found that low K content in natural habitats was a restrictive factor in the growth and distribution of M. hangchowensis, and soil K-deficiency caused by acid rain worsened the situation of M. hangchowensis, while M. dianthera could well acclimate to the increasing K-deficiency. We suggest that controlling the acid rain and applying K fertilizers may be an effective way to rescue the endangered M. hangchowensis. Project supported by the National Natural Science Foundation of China (No. 30570113) and the Research Fund for the Doctoral Program of Higher Education (No. 20060335008), China  相似文献   

17.
Aquilaria agallocha can produce fragrant agarwood used for incense, traditional medicine and other products. An efficient plant regeneration system was established via organogenesis from shoots developed from seedlings ofAquilaria agallocha. Shoots generated many buds on MS medium supplemented with 1.3 μmol/L BA (6-benzylaminopurine) in the first 7 weeks, and the buds elongated on MS medium with 1.3 μmol/L BA+0.5 μmol/L NAA (naphthaleneacetic acid) in another 7 weeks, 2.3 shoots 2 cm in length per explant were obtained within 14 weeks. Plantlets were rooted on 1/2 MS medium after being immersed in 5 μmol/L NAA for 48 h, 96.7% of the roots grew up two weeks later. All plantlets that survived acclimatization grew well in the pots. Project supported by the National Natural Science Foundation of China (No. 30070066) and the Science and Technology Project of Guangzhou City (No. 2003J1-C0241), China  相似文献   

18.
Breast cancer is one of the leading causes of death in women today. Some of the patients are hereditary, with a large proportion characterized by mutation in BRCA1 and/or BRCA2 genes. In this review, we provide an overview of these two genes, focusing on their relationship with hereditary breast cancers. BRCA1/2 associated hereditary breast cancers have unique features that differ from the general breast cancers, including alterations in cellular molecules, pathological bases, biological behavior, and a different prevention strategy. But the outcome of BRCA1/2 associated hereditary breast cancers still remains controversial; further studies are needed to elucidate the nature of BRCA1/2 associated hereditary breast cancers. Project supported by the National Natural Science Foundation of China (No. 30772510) and the Joint Program of Ministry of Health and Zhejiang Provincal Government of China (No. WKJ2006-2-008)  相似文献   

19.
1, 10-Phenanthroline (phen) was tested as a complexing agent for on-line preconcentration of iron on RP-C18 material in a microcolumn with flow injection coupled with flame atomic absorption spectrometer (FI-FAAS). The on-line formed Fe(II)-phen complexes were adsorbed on the C18 sorbent material. Various parameters affecting the on-line Fe(II)-phen complex formation and its subsequent adsorption in the microcolumn as well as its elution into the nebulizer of AAS were optimized. A 2.5×10−3 mol/L phen in 2% through the microcolumn for 30 s. The adsorbed Fe(II)-phen complexes in the microcolumn were eluted with ethanol in 10 s into the nebulizer of AAS. Ascorbic acid (5×10−4 mol/L) was added to the sample solution for the reduction of Fe(III) to Fe(II). A good precision (RSD=1.1%,n=10), high enrichment factor (19) and sample throughput (90 h−1) with detection limit (3σ) of 3 μg/L were obtained. The method was applied on standard reference materials (i. e. mussel and tomato leaves,) for iron determination and yielded results agreeing well with certified values. Project supported by the Zhejiang Provincial Natural Science Foundation of China and Zhejiang Environmental Protection Foundation From Pakistan Institute of Nuclear Science & Technology, Islamabad, Pakistan and now ZJ University, Ph. D. student.  相似文献   

20.
1　Introduction　Ahugeamountofliteratureexistsonthestudyofi dentifyingtracemetalionsbymeansofspectropho tometry[1 3] ,fluorimetry[4 6 ] aswellas polarogra phy[7 9] ,whichhaveactiononlocatingtheendpointoftheindicatingreaction .Howeverbothspectropho tometryandfluorimetryareeasytobeinterferedbycolororprecipitation ,whilepolarographyhasanissueofmercurypollution .Thecatalyzingkineticanalysishasthecharacteristicsofhighsensitivityandspeedi ness.Oscillographicpotentiometryisasimpleintu itionisticanal…  相似文献   

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