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1.
Donato Torre Agostino Pugliese Carlo Quadrelli Carmen Sampietro Stefania Rossi 《FEMS microbiology letters》1989,57(2):209-212
The total number of lymphocytes in the bronchoalveolar lavage (BAL) fluids significantly increased in mice injected intravenously with pertussis toxin (PT), while the absolute number of alveolar macrophages markedly decreased. This finding probably reflects the lymphocyte accumulation in interstitial spaces as we previously observed in mice injected with PT. In addition, indomethacin, at lower dosage (0.5 mg/kg) prevented peripheral lymphocytosis and lymphocyte accumulation in the alveolar spaces of the lungs of mice injected with PT. These results provide evidence that PT is responsible for lymphocyte accumulation together with a marked decrease of alveolar macrophages in the lungs of treated mice; moreover, indomethacin is effective in preventing bronchoalveolar changes caused by PT. 相似文献
2.
The stability constants of the binary and the ternary complexes of Pu4+ have been measured for certain carboxylate and aminocarboxylate ligands in aqueous solution of I = 5.0 M (1 M perchloric acid + 4 M ionic strength perchlorate media) and temperatures of 0-45 °C by the solvent extraction technique. The stability constants of the binary and the ternary complexes increased with increased temperature. The complexation enthalpy and entropy of the binary Pu-Ox and the ternary Pu-EDTA-Ox and DGA complexes indicated the stability of these complexes is due to the highly favorable entropy contribution while complexation enthalpies either oppose complexation or are weakly favorable. 相似文献
3.
Trivalent chromium (Cr3+) is essential for animal and human health, whereas hexavalent Cr (CrO4
2−) is a potent carcinogen and extremely toxic to animals and humans. Thus, the accumulated Cr in food plants may represent
potential health hazards to animals and humans if the element is accumulated in the hexavalent form or in high concentrations.
This study was conducted to determine the extent to which various vegetable crops absorb and accumulate Cr3+ and CrO4
2− into roots and shoots and to ascertain the different chemical forms of Cr in these tissues. Two greenhouse hydroponic experiments
were performed using a recirculating-nutrient culture technique that allowed all plants to be equally supplied with Cr at
all times. In the first experiment, 1 mg L−1 Cr was supplied to 11 vegetable plant species as Cr3+ or CrO4
2−, and the accumulation of Cr in roots and shoots was compared. The crops tested included cabbage (Brassica oleracea L. var. capitata L.), cauliflower (Brassica oleracea L. var. botrytis L.), celery (Apium graveolens L. var. dulce (Mill.) Pers.), chive (Allium schoenoprasum L.), collard (Brassica oleracea L. var. acephala DC.), garden pea (Pisum sativum L.), kale (Brassica oleracea L. var. acephala DC.), lettuce (Lactuca sativa L.), onion (Allium cepa L.), spinach (Spinacia oleracea L.), and strawberry (Fragaria ×
ananassaDuch.). In the second experiment, X-ray absorption spectroscopy (XAS) analysis on Cr in plant tissues was performed in roots
and shoots of various vegetable plants treated with CrO4
2− at either 2 mg Cr L−1 for 7 d or 10 mg Cr L−1 for 2, 4 or 7 d. The crops used in this experiment included beet (Beta vulgaris L. var. crassa (Alef.) J. Helm), broccoli (Brassica oleracea L. var. Italica Plenck), cantaloupe (Cucumis melo L. gp. Cantalupensis), cucumber (Cucumis sativus L.), lettuce, radish (Raphanus sativus L.), spinach, tomato (Lycopersicon lycopersicum (L.) Karsten), and turnip (Brassica rapa L. var. rapifera Bailey). The XAS speciation analysis indicates that CrO4
2− is converted in the root to Cr3+ by all plants tested. Translocation of both Cr forms from roots to shoots was extremely limited and accumulation of Cr by
roots was 100-fold higher than that by shoots, regardless of the Cr species supplied. Highest Cr concentrations were detected
in members of the Brassicaceae family such as cauliflower, kale, and cabbage. Based on our observations and previous findings
by other researchers, a hypothesis for the differential accumulation and identical translocation patterns of the two Cr ions
is proposed.
Received: 27 February 1998 / Accepted: 2 April 1998 相似文献
4.
Combined antibacterial effects of tissue‐tolerable plasma and a modern conventional liquid antiseptic on chronic wound treatment 下载免费PDF全文
Martin Klebes Christin Ulrich Franziska Kluschke Alexa Patzelt Staffan Vandersee Heike Richter Adrienne Bob Johanna von Hutten Jorien T. Krediet Axel Kramer Jürgen Lademann Bernhard Lange‐Asschenfeld 《Journal of biophotonics》2015,8(5):382-391
Potential antimicrobial effects of sequential applications of tissue‐tolerable plasma (TTP) and the conventional liquid antiseptic octenidine dihydrochloride (ODC) were investigated. 34 patients with chronic leg ulcers were treated with TTP, ODC or a combination of both. The bacterial colonization was measured semi‐quantitatively before and immediately after treatment and changes in the microbial strains' compositions before and after antiseptic treatments were analyzed. All antiseptic procedures reduced the bacterial counts significantly. The sequential application of TTP and ODC displayed the highest antimicrobial efficacy. Me combined use of TTP and conventional antiseptics might represent the most efficient strategy for antiseptic treatment of chronic wounds. (© 2014 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
5.
Two platinum(IV) complexes, [Pt(4bt)Cl4] (4) and [Pt(dpyam)Cl4]·DMF (5) (where 4bt is 4,4′-bithiazole and dpyam is 2,2′-dipyridylamine) were prepared from the reaction of H2PtCl6·6H2O with 4,4′-bithiazole and 2,2′-dipyridylamine, respectively, in methanol. Both complexes were fully characterized and their structures were determined by the X-ray diffraction method. These complexes have a bidentate nitrogenous ligand with four chloride anions attached to a Pt(IV) metal in a distorted octahedral environment. These complexes along with three previously reported analogous complexes were used for in vitro cytotoxicity evaluation against four cultures, NIH-3T3, Caco-2, HT-29 and T47D by MTT assay. The methyl group position in the ligand plays an important role in the cytotoxicity of relevant compounds in different cultures. Interestingly, in some cases, the IC50 values of the new complexes were higher for normal cells but lower against cancer cells in comparison with cisplatin, especially in T47D (breast ductal carcinoma). 相似文献
6.
Jimin Wang 《Protein science : a publication of the Protein Society》2018,27(2):411-420
Three basic electronic properties of molecules, electron density (ED), charge density (CD), and electrostatic potentials (ESP), are dependent on both atomic mobility and occupancy of components in the molecules. Small protein subunits may bind large macromolecular complexes with a reduced occupancy or an increased atomic mobility or both due to affinity‐based functional regulation, and so may substrates, products, cofactors, ions or solvent molecule to the active sites of enzymes. A quantitative theory is presented in this study that describes the dependence of atomic functions on atomic B‐factor in Fourier transforms of the corresponding maps. An application of this theory is described to an experimental ED map at 1.73‐Å resolution, and to an experimental CD map at 2.2‐Å resolution. All the three density functions are linearly proportional to occupancy when the structure factor F(000) term of Fourier transforms of experimental density maps is included. Upon application of this theory to both experimental CD and ESP maps recently reported for photosystem II‐light harvesting complex II supercomplex at 3.2‐Å resolution, the occupancy of two extrinsic protein subunits PsbQ and PsbP is determined to be 20.4 ± 0.2%, and the negative mean ESP value of vitreous ice displaced by the supercomplex on electron scattering path is estimated to be 3% of the mean ESP value of protein α‐helices. 相似文献
7.
United States Pharmacopeia dissolution apparatus II (paddle) and III (reciprocating cylinder) coupled with automatic sampling
devices and software were used to develop a testing procedure for acquiring release profiles of colon-specific drug delivery
system (CODES™) drug formulations in multi-pH media using acetaminophen (APAP) as a model drug. System suitability was examined. Several
important instrument parameters and formulation variables were evaluated. Release profiles in artificial gastric fluid (pH
1.2), intestinal fluid (pH 6.8), and pH 5.0 buffer were determined. As expected, the percent release of APAP from coated core
tablets was highly pH dependent. A release profile exhibiting a negligible release in pH 1.2 and 6.8 buffers followed by a
rapid release in pH 5.0 buffer was established. The drug release in pH 5.0 buffer increased significantly with the increase
in the dip or paddle speed but was inversely related to the screen mesh observed at lower dip speeds. It was interesting to
note that there was a close similarity (f
2=80.6) between the release profiles at dip speed 5 dpm and paddle speed 100 rpm. In addition, the release rate was reduced
significantly with the increase in acid-soluble Eudragit E coating levels, but lactulose loading showed only a negligible
effect. In conclusion, the established reciprocating cylinder method at lower agitation rates can give release profiles equivalent
to those for the paddle procedure for CODES™ drug pH-gradient release testing. Apparatus III was demonstrated to be more convenient and efficient than apparatus II by
providing various programmable options in sampling times, agitation rates, and medium changes, which suggested that the apparatus
II approach has better potential for in vitro evaluation of colon-specific drug delivery systems. 相似文献
8.
Adel Hamza Ning-Ning Wei Ce Hao Zhilong Xiu 《Journal of biomolecular structure & dynamics》2013,31(11):1236-1250
In this work, we extend our previous ligand shape-based virtual screening approach by using the scoring function Hamza–Wei–Zhan (HWZ) score and an enhanced molecular shape-density model for the ligands. The performance of the method has been tested against the 40 targets in the Database of Useful Decoys and compared with the performance of our previous HWZ score method. The virtual screening results using the novel ligand shape-based approach demonstrated a favorable improvement (area under the receiver operator characteristics curve AUC?=?.89?±?.02) and effectiveness (hit rate HR1%?=?53.0%?±?6.3 and HR10%?=?71.1%?±?4.9). The comparison of the overall performance of our ligand shape-based method with the highest ligand shape-based virtual screening approach using the data fusion of multi queries showed that our strategy takes into account deeper the chemical information of the set of active ligands. Furthermore, the results indicated that our method are suitable for virtual screening and yields superior prediction accuracy than the other study derived from the data fusion using five queries. Therefore, our novel ligand shape-based screening method constitutes a robust and efficient approach to the 3D similarity screening of small compounds and open the door to a whole new approach to drug design by implementing the method in the structure-based virtual screening. 相似文献
9.
The stromacentre (SC), a particular structure in the plastids of Avena, was isolated from etioplasts of Avena sativa by density gradient centrifugation and then analyzed and compared with ribulose-1,5-bisphosphate carboxylase-oxygenase (RuBPCase) from A. sativa, with pyrenoids of Chlorella vulgaris and with the stromacentre of Opuntia. Purified SC-elements consisted of protein subunits with a relative molecular weight of 63 kDa, different from the isolated RuBPCase of A. sativa as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After peptide mapping, the proteolytic cleavage patterns of the 63-kDa protein were also found to be different from those of the RuBPCase. Antibodies against SC-elements, RuBPCase, and the large subunit of RuBPCase were produced. Ouchterlony double immunodiffusion tests did not give crossreactions between the SC-elements and RuBPCase or the large subunit of this enzyme. Immunogold labelling of ultrathin sections showed that antibodies against the SC-elements marked the stromacentre in Avena, but not the pyrenoids in Chlorella. Antibodies against the large subunit of RuBPCase, however, did not label the SC, but labelled the stroma of the plastids in Avena and the pyrenoids of Chlorella. In Opuntia, a comparable structure described as an SC was not labelled by any of the antisera. Immunoelectrophoretical investigations demonstrated a strong correlation between the presence of the 63-kDa protein and the occurrence of the SC in different Avena species with and without SC.Abbreviations RuBPCase
ribulose-1,5-bisphosphate carboxylase/oxygenase
- SC
stromacentre
- SDS-PAGE
sodium dodecyl sulfate-polyacrylamide gel electrophoresis
- Tris
2-amino-2-(hydroxymethy;)-1,3-propanediol
Dedicated to Professor Ludwig Bergmann on the occasion of his 60th birthday 相似文献
10.
11.
Nine triorganotin(IV) complexes of the type R3SnL (L = L1 R = Me 1, Ph 2, PhCH23; L = L2 R = Me 4, Ph 5, PhCH26; L = L2 R = Me 7, Ph 8, PhCH29) have been obtained by reaction of new Schiff base HL1, HL2 or HL3 with triorganotin(IV) chloride in the presence of sodium ethoxide. All the complexes 1-9 were characterized by elemental, IR and NMR spectra analyses. Except for complexes 3, 4, 6, 9, the others were also characterized by X-ray crystallography diffraction analyses, which revealed that complexes 1, 2, 5, 7, 8 were four coordinated and displayed a capped tetrahedron. 相似文献
12.
Muhammad Naeem Khan Muhammad Rasul Jan Jasmin Shah Sang Hak Lee Young Ho Kim 《Luminescence》2013,28(6):915-921
A highly sensitive and simple method for identifying sulpiride in pharmaceutical formulations and biological fluids is presented. The method is based on increased chemiluminescence (CL) intensity of a luminol–H2O2 system in response to the addition of Cr (III) under alkaline conditions. The CL intensity of the luminol–H2O2–Cr (III) system was greatly enhanced by the addition of sulpiride and the CL intensity was proportional to the concentration of sulpiride in a sample solution. Various parameters affecting the CL intensity were systematically investigated and optimized for determination of the sulpiride in a sample. Under the optimum conditions, the CL intensity was proportional to the concentration of sulpiride in the range of 0.068–4.0 µg/mL, with a good correlation coefficient of 0.997. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 8.50 × 10‐6 µg/mL and 2.83 × 10‐5 µg/mL, respectively. The method presented here produced good reproducibility with a relative standard deviation (RSD) of 2.70% (n = 7). The effects of common excipients and metal ions were studied for their interference effect. The method was validated statistically through recovery studies and successfully applied for the determination of sulpiride in pure form, pharmaceutical preparations and spiked human plasma samples. The percentage recoveries were found to range from 99.10 to 100.05% for pure form, 98.12 to 100.18% for pharmaceutical preparations and 97.9 to 101.4% for spiked human plasma. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
13.
By reaction of 2,6-diformyl-4-methylphenol (BDF) with the amino acids l-His and l-Ala in the presence of VOCl2, two new oxovanadium(IV) complexes with the ligand obtained by the 1:2 condensation of BDF with the amino acids, BDF-His and BDF-Ala, were synthesised. The compounds were characterised in the solid state by elemental analyses, IR, CD and magnetic susceptibility measurements, and in the mother liquor by EPR. In water-containing solutions, BDF-Ala and BDF-His partially hydrolyse but the degree of Schiff base formation increases upon addition of VOSO4. The equilibria in the system VIVO2+ + BDF-His were studied by spectroscopic methods (EPR, CD and UV-Vis) in the pH range 1.5-12. The coordination behaviour of the ligand changes as the pH increases, leading to the formation of four main species all involving Ophen as donor atom. Plausible binding modes are discussed based on the spectroscopic results. 相似文献
14.
Lin J Zhang Z Zeng S Zhou S Liu BF Liu Q Yang J Luo Q 《Biochemical and biophysical research communications》2006,346(4):1136-1141
The apoptotic pathway in higher eukaryotes remains controversial with respect to the necessity of activation of caspase-3 in TRAIL (tumor necrosis factor-related apoptosis-inducing ligand)-treated cells. In this study, a fluorescence resonance energy transfer (FRET) probe was developed to image the activation of caspase-3 and the related apoptotic pathway in TRAIL-treated cells in real time. Both kinds of apoptotic pathways were observed simultaneously in the same experiment proceeding from activation and non-activation of caspase-3. The total apoptotic rate was 56.08%, the apoptotic rates for activation and non-activation of caspase-3 pathways were 21.5% and 34.58%, respectively, which were examined later for Hoechst 33258 staining and morphological characteristics. The apoptotic rate due to the activation of caspase-3 pathways in TRAIL-treated cells has been independently measured to be around 25.11% by capillary electrophoresis (CE) analysis, which confirmed the apoptotic rate due to activation of caspase-3 pathways as found by FRET analysis. This result also suggests that rest apoptosis is preceded by caspase-3-independent pathways, as CE has the ability to quantitatively detect caspase-dependent apoptosis. The observation of the coexistence of caspase-3-dependent and caspase-3-independent apoptotic pathways in the TRAIL-treated cells was unusual in comparison with the previous reports. 相似文献
15.
Solinís MA de la Cruz Y Calvo B Hernández RM Gascón AR Goñi I Gurruchaga MD Pedraz JL 《Chirality》2002,14(10):806-813
We studied the release of salbutamol and ketoprofen enantiomers from HPMC K100M matrices containing two types of cellulose derivatives: cellulose tris (3,5-dimethylphenylcarbamate) and cellulose tris (2,3-dichlorophenylcarbamate), chiral excipients used as stationary phases for liquid chromatography. These matrices provided an extended release of both drugs. Ketoprofen release from formulations elaborated with cellulose tris (2,3-dichlorophenylcarbamate) was by anomalous transport, because the value of n (release exponent of the diffusion equation) ranged between 0.60-0.68, whereas for all other formulations the value of exponent n ranged from 0.50-0.54. The drug thus diffuses through the matrix and is released following a quasi-Fickian diffusion mechanism (stereoselective process). The matrices preferentially retained R-salbutamol and S-ketoprofen and cellulose tris (3,5-dimethylphenylcarbamate) showed more capacity of chiral discrimination for both drugs than cellulose tris (2,3-dichlorophenylcarbamate). Moreover, we observed that stereoselectivity is dependent on the amount of chiral excipient in the formulation. Diffusion tests confirmed the chiral interaction between drugs and cellulose derivatives observed in the dissolution assays except for matrices elaborated with ketoprofen and cellulose tris (2,3-dichlorophenylcarbamate), where the low stereoselectivity observed with the matrices is due to the presence of HPMC K100M. We conclude that the inclusion of these cellulose derivatives in HPMC matrices does not result in a relevant stereoselectivity with respect to the two drugs studied. 相似文献
16.
Aktham N. Jasim Azhar Kamel Nagham S. Al-Awadi Hussein Fares Abd-Alrazack 《Luminescence》2023,38(3):360-368
A simple, rapid, sensitive and inexpensive approach is described in this work based on a combination of solid-phase extraction of 8-hydroxyquinoline (8HQ), for speciation and preconcentration of Cr(III) and Cr(VI) in river water, and the direct determination of these species using a flow injection system with chemiluminescence detection (FI–CL) and a 4-diethylamino phenyl hydrazine (DEAPH)–hydrogen peroxide system. At different pH, the two forms of chromium [Cr(III) and Cr(VI)] have different exchange capacities for 8HQ, therefore two columns were constructed; the pH of column 1 was adjusted to pH 3 for retaining Cr(III) and column 2 was adjusted to pH 1 for retaining of Cr(VI). The sorbed Cr(III) and Cr(VI) species were eluted from columns using 3.0 ml of 0.1 N of HCl and 3.0 ml of 0.1 N of NaOH, respectively. The flow injection–chemiluminescence (FI–CL) method is based on light emitted due to the oxidation of DEAPH by the H2O2 in the presence of Cr(III), which catalyzes the reaction. The flow cell is a transparent coiled tube made from glass (2.0 × 4.0, inner and outer diameter) and located close to the photodetector. The flow parameters: flow rate, sample volume, flow cell length, and distance to the CL detector were studied and optimized. Under optimum flow conditions, the Cr(III) concentration can be determined over the range 5–350 μg L−1 with a limit of detection of 1.2 μg L−1, as the Cr(III) concentration is proportional to the intensity of the CL signal. The relative standard deviations (%) for 10 and 50 μg L−1 Cr(III) were 1.2% and 3.2%, respectively. The effects of Al(III), Cd(II), Zn(II), Hg(II), Pb(II), Co(II), Cu(II), Ni(II), Mn(II), Ca(II), and Fe(III) were investigated. The proposed method is highly selective and sensitive, enabling a rapid determination of the Cr(III) amount in the presence of other interfering metals. Finally, the FI–CL method was examined in five river water samples with excellent recoveries. 相似文献
17.
软珊瑚(Sinularia flexibilis)和柳珊瑚(Plexaura homomalla)化学防御物质研究进展 总被引:1,自引:0,他引:1
软珊瑚(Sinularia flexibilis)和柳珊瑚(Plexaura homomalla)属于海洋低等无脊椎动物,虽然这些动物自身缺乏有效的物理防御手段,却能在竞争激烈的海洋环境中生存与繁衍,这主要是依靠其次级代谢产物的化学防御作用.这些次级代谢产物聚积在体内或释放到环境中,作用主要体现在抵御捕食者、抗病原微生物、克生与防附着等方面.珊瑚化学防御物质的研究有助于探讨珊瑚与其环境中其它生物的化学生态关系,属于海洋化学生态学研究的重要内容之一,其研究方法和思路对海洋活性天然产物乃至海洋新药先导化合物的发现,具有重要的启迪作用.综述了软珊瑚和柳珊瑚化学防御物质的研究进展,并阐释了软珊瑚和柳珊瑚中具有拒捕食、克生、防生物附着等生物活性的次级代谢产物的结构及其化学防御作用. 相似文献
18.
苦瓜籽核糖体失活蛋白的理化性质及生物活性 总被引:13,自引:0,他引:13
采用硫酸铵分级分离,假配基亲和层析和SephacrylS-100分子筛层析等方法,从苦瓜籽中获得核糖体失活蛋白(RIP).经SDS-PAGE、PAGE、IEF和PAS方法分析均表明为单一蛋白着色带或单一糖蛋白着色带.根据SDS-PAGE和Sephadex G-150分子筛层析结果计算其相对分子质量为3.0×104,经IEF-PAGE结果计算其pI为8.9~9.0.对无细胞系统中蛋白质生物合成抑制活性明显,其IC50为5.3×10- 10 m ol/L左右.体外生物活性试验结果表明其对人肝癌细胞、Vero、SP2/0、3T3、Kb、Navana 等肿瘤细胞株均表现有不同程度的抑制作用.而对完整细胞人胚肺二倍体细胞却毒性极小.因此,上述实验结果为该RIP的进一步深入研究和有可能开发成免疫毒素的高效弹头药物提供了一定的工作基础. 相似文献
19.
Morris水迷宫在啮齿目动物的空间学习与记忆的研究中被广泛使用。研究表明摄食抗氧化剂能够增强空间学习与记忆能力。本文目的在于研究构树黄酮对昆明小鼠的空间学习与记忆能力的影响。用构树黄酮固体脂质纳米粒对小鼠灌胃4周,然后进行Morris水迷宫测试。与对照组相比,实验组小鼠的各项指标均有显著改善。这表明构树黄酮能显著增强小鼠的空间学习与记忆能力。同时研究还表明构树黄酮对小鼠的生长发育没有影响。 相似文献
20.
This paper reports a flow‐injection chemiluminescence method for the determination of ofloxacin (OFLX) using the Ru(bpy)2(CIP)2+–Ce(IV) system. Under the optimum conditions, the relative CL intensity was proportional to the concentration of OFLX in the range 3.0 × 10–8–1.0 × 10–5 mol/L and the detection limit was 4.2 × 10–9 mol/L. The proposed method has been successfully applied to the determination of ofloxacin in pharmaceuticals and human urine. The chemiluminescence mechanism of the system is also discussed. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献