铈对人膀胱癌细胞基质金属蛋白酶-9表达及活性的影响

以体外培养的人膀胱癌细胞为研究对象,采用四唑盐比色检测法、明胶酶谱法研究Ce4+对人膀胱癌细胞的存活、基质金属蛋白酶 9表达与活性的影响。结果表明,低浓度稀土(0 01mmol·L-1)对细胞的生长没有显著影响,但强烈抑制基质金属蛋白酶 9的表达,而此浓度Ce4+能提高基质金属蛋白酶 9的活性。高浓度稀土(1 0mmol·L-1)对细胞的生长、基质金属蛋白酶 9表达与活性均有显著的抑制作用。     

插拔式压电肿瘤标志物微阵列免疫传感器的研制

以AT切型、基频10 MHz的金膜石英晶体作为换能器,通过螺旋检测池固定夹具构建一种新型插拔式压电石英晶体传感器,并组装成2×5型压电肿瘤标志物微阵列免疫传感器。研究了传感器的响应特性及参数。该微阵列传感器在甲胎蛋白(AFP)、癌胚抗原(CEA)、前列腺特异性抗原(PSA)和人绒毛膜促性腺激素(hCG)质量浓度分别为20~640μg/L、1.56~50μg/L、1.25~50μg/L、2.5~250 mIU/mL的范围内,压电石英晶体振荡频率偏移值对肿瘤标志物浓度均呈现良好的响应特性。应用微阵列传感器测定68例临床血清标本,结果与化学发光免疫分析法符合(相关系数分别为0.92、0.90、0.91、0.94)。该压电肿瘤标志物传感器微阵列具有结构简单、操作方便、稳定性好、灵敏度和特异性高,不需标记,能实时检测和重复使用等优点,可用于临床实验诊断,具有临床推广应用价值。     

In vitro and in vivo metabolisms of K-48

Metabolic pathways of the oxime K-48 have been elucidated by means of in vitro and in vivo experiments. K-48 exposure to rat liver microsomal fraction resulted in the formation of a hydroxylated derivative, in addition to a small molecular fragment. The in vivo metabolism in rats was investigated after intramuscular administration of 50 μmol oxime. K-48 was present in the rat serum in unchanged form. Similarly, the analysis of rat cerebrospinal fluid indicated the sole occurrence of unchanged K-48. In contrast, unchanged K-48 was not found in the rat urine, where only the metabolite generated by epoxidation on the alkyl chain connecting the two pyridinium rings was present. The presence of unchanged K-48 in the serum and cerebrospinal fluid facilitates quantitative determination using HPLC separation and ultraviolet absorbance detection. Figure Suggested metabolic pathways of K-48     

Lipids from Flowers and Leaves of <Emphasis Type="Italic">Artemisia annua</Emphasis> and Their Biological Activity

Chemical, chromatographic, and spectral methods were used to show that the main components of the lipid extract of flowers and leaves are free and bound aliphatic and cyclic alcohols (sterols and triterpenols) and essential oil. It was shown that the lipid extract of Artemisia annua has a positive influence on skin metabolism and possesses anti-inflammatory activity.__________Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 226–229, May–June, 2005.     

Mapping phosphorylation rate of fluoro-deoxy-glucose in rat brain by F chemical shift imaging

¹⁹F magnetic resonance spectroscopy (MRS) studies of 2-fluoro-2-deoxy-d-glucose (FDG) and 2-fluoro-2-deoxy-d-glucose-6-phosphate (FDG-6P) can be used for directly assessing total glucose metabolism in vivo. To date, ¹⁹F MRS measurements of FDG phosphorylation in the brain have either been achieved ex vivo from extracted tissue or in vivo by unusually long acquisition times. Electrophysiological and functional magnetic resonance imaging (fMRI) measurements indicate that FDG doses up to 500 mg/kg can be tolerated with minimal side effects on cerebral physiology and evoked fMRI-BOLD responses to forepaw stimulation. In halothane-anesthetized rats, we report localized in vivo detection and separation of FDG and FDG-6P MRS signals with ¹⁹F 2D chemical shift imaging (CSI) at 11.7 T. A metabolic model based on reversible transport between plasma and brain tissue, which included a non-saturable plasma to tissue component, was used to calculate spatial distribution of FDG and FDG-6P concentrations in rat brain. In addition, spatial distribution of rate constants and metabolic fluxes of FDG to FDG-6P conversion were estimated. Mapping the rate of FDG to FDG-6P conversion by ¹⁹F CSI provides an MR methodology that could impact other in vivo applications such as characterization of tumor pathophysiology.     

Simultaneous acquisition of phosphocreatine and inorganic phosphate images for Pi:PCr ratio mapping using a RARE sequence with chemically selective interleaving

The ratio of inorganic phosphate to phosphocreatine (Pi:PCr) is a validated marker of mitochondrial function in human muscle. The magnetic resonance imaging rapid acquisition with relaxation enhancement (RARE) pulse sequence can acquire phosphorus-31 (³¹P) images with higher spatial and temporal resolution than traditional spectroscopic methods, which can then be used to create Pi:PCr ratio maps of muscle regions. While the ³¹P RARE method produces images that reflect the content of the ³¹P metabolites, it has been limited to producing an image of only one chemical shift in a scan. This increases the scan time required to acquire images of multiple chemical shifts as well as the likelihood of generating inaccurate Pi:PCr maps due to gross motion. This work is a preliminary study to demonstrate the feasibility of acquiring Pi and PCr images in a single scan by interleaving Pi and PCr chemical shift acquisitions using a chemically selective radiofrequency excitation pulse. The chemical selectivity of the excitation pulse evaluated and the Pi:PCr maps generated using the interleaved Pi and PCr acquisition method with the subject at rest and during exercise are compared to those generated using separate Pi and PCr acquisition scans. A paired t test indicated that the resulting Pi:PCr ratios for the exercised forearm muscle regions were not significantly different between the separate Pi and PCr acquisition method (3.18±1.53) (mean±standard deviation) and the interleaved acquisition method (3.41±1.66). This work demonstrates the feasibility of creating Pi:PCr ratio maps in human muscle with Pi and PCr images acquired simultaneously by interleaving between the Pi and PCr resonances in a single scan.     

Synthesis of Thioproline Salicylic Acid Samarium Complex and Microcalorimetric Study on Effects of the Complex on the Growth Metabolism of S. pombe Cells

The product from reaction of samarium chloride hexahydrate with salicylic acid and thioproline, [Sm(C₇H₅O₃)₂·(C₄H₆NO₂S)]·2H₂O (TSAS), was synthesized and characterized by IR, elemental analysis and thermogravimatric analysis. Particularly, the effect of the compounds TSAS, SmCl₃·6H₂O, C₇H₆O₃ and C₄H₇NO₂S on the growth and metabolism of S. pombe by a TAM Air isothermal calorimeter at 32°C is also reported. The thermokinetic parameters, which included the microbial growth rate constant (κ), inhibition ratio (I) and half inhibition concentration (IC₅₀), were obtained. The results showed that all the compounds TSAS, SmCl₃·6H₂O, C₇H₆O₃ and C₄H₇NO₂S possessed the bi‐directional biological effect and Hormesis effect. These stimulate the growth of the S. pombe at lower concentration, but inhibit the growth at higher concentration. The half inhibition concentrations (IC₅₀) of TSAS, SmCl₃·6H₂O, C₄H₇NO₂S and C₇H₆O₃ were found to be 0.732, 0.746, 0.746 and 1.43 mmol·L⁻¹, respectively. The inhibition ability of these compounds on the growth of the S. pombe has been observed to decrease in the order TSAS>SmCl₃·6H₂O=C₄H₇NO₂S>C₇H₆O₃. Moreover, the effect of TSAS on the growth and cytokinesis of S. pombe was investigated by cytomorphology and FT IR spectroscopy technique. The results indicated that TSAS had a direct impact on apoptosis, and could also inhibit the cell growth by reducing cytokinesis and the binding locations of drug (TSAS) in S. pombe cells could be the proteins and nucleic acid.     

Characterization of [6]-gingerol metabolism in rat by liquid chromatography electrospray tandem mass spectrometry

[6]-Gingerol is a structural analog of capsaicin, an agonist of the transient receptor potential channel vanilloid 1, which is known to have therapeutic properties for the treatment of pain and inflammation. A selective and sensitive quantitative method for the determination of [6]-gingerol by HPLC-ESI/MS/MS was developed. The method consisted of a protein precipitation extraction followed by analysis using liquid chromatography electrospray tandem mass spectrometry. The chromatographic separation was achieved using a Thermo 100 × 2.1 mm C(8) column combined with an isocratic mobile phase composed of acetonitrile, water and formic acid (80:20:0.1) at a flow rate of 250 μL/min. The mass spectrometer was operating in SRM mode and an analytical range set at 20-5000 ng/mL was used to construct a calibration curve in rat plasma. The interbatch precision (%CV) and accuracy (%NOM) observed were 2.9-10.8% and 98.1-102.1% in rat plasma. Similarly, precision and accuracy in rat liver microsomal suspension were also evaluated at nominal concentrations of 1, 25 and 100 μm; the precision (%CV) was <3.4% and the accuracy (%NOM) observed ranged from 89.7 to 109.4%. An in vitro metabolic stability study using rat liver microsomes was performed to determine intrinsic clearance of [6]-gingerol. The results show slow degradation with a T(1/2) of 163 min and relatively low intrinsic clearance suggesting that phase I metabolism may not be a major contributor of the drug clearance. Further analyses were performed to characterize in vitro and in vivo metabolites. Three main phase I metabolites and four phase II metabolites were identified by HPLC-MS/MS and HPLC-MSD TOF. However, the results suggest that glucuronidation of hydroxylated [6]-gingerol is the primary metabolite excreted in rat urine.     

Mass spectrometric studies on the in vitro generated metabolites of SIRT1 activating drugs for doping control purposes

The enzyme SIRT1 is a metabolic key regulator in mitochondrial biogenesis, fat and glucose metabolism. Its activation through pharmaceutical SIRT1 activators such as SRT2104 results in an increased deacetylation of substrates representing important targets for the treatment of metabolic diseases. Moreover, SRT1720 was found to enhance the physical performance of mice. As SIRT1 activators might therefore be relevant in a doping control context, metabolism studies of target substances need be conducted in order to develop a detection assay for SIRT1 activators in urine. In the present study, the in vitro metabolism of five SIRT1 activators was investigated using human liver microsomes. The mass spectrometric behavior of the resulting metabolites following positive electrospray ionization and collision‐induced dissociation was elucidated by high‐resolution/high‐accuracy (tandem) mass spectrometry, and confirmation of the structure of a major metabolite of SRT1720 was accomplished by chemical synthesis. Subsequently, a screening procedure for urine samples was developed employing liquid–liquid‐extraction and liquid chromatography/tandem mass spectrometry based on diagnostic ion transitions recorded in multiple reaction monitoring mode and the use of d₈‐SRT1720 as deuterated internal standard. The method was validated with regard to specificity, sensitivity (limit of detection 0.5 ng/ml), recovery (88–99%) and imprecision (7–18%) as well as ion suppression/enhancement effects (<10%), demonstrating its fitness‐for‐purpose for sports drug testing applications. Copyright © 2013 John Wiley & Sons, Ltd.     

Metalloporphyrin-catalyzed hydroxylation of the N,N-dimethylamide function of the drug molecule SSR180575 to a stable N-methyl-N-carbinolamide

The metalloporphyrin-catalyzed oxidation of SSR180575, a ligand of the peripheral benzodiazepine receptor, that contains both N-methylindole and N,N-dimethylamide functions, produces a high yield of a stable carbinolamide derivative.