首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
为研究Graves病(GD)患者经^131I治疗后血浆和红细胞锌(Zn)含量的变化及其临床意义,采用原子吸收分光光谱法(AAS)和放射免疫分析法(Rn)分别检测了40例GD患者、20例经^131I治疗后甲状腺功能恢复至正常水平GD患者与30名健康人血浆和红细胞Zn的含量以及血浆甲状腺激素水平。结果表明,GD组红细胞Zn含量明显低于对照组(P<0.01);血浆Zn含量虽略低于对照组,但无统计学意义(P<0.05);且Zn与FT4呈明显负相关(P<0.01)、与TSH呈正相关(P<0.05)。GD治疗缓解组红细胞Zn明显高于治疗前(P<0.01),血浆Zn明显低于治疗前(P<0.05);红细胞Zn检测GD的敏感性与特异性分别为95.0%与96.7%。提示GD患者存在红细胞Zn含量改变,甲状腺激素可能干扰红细胞Zn的代谢,同时测定红细胞Zn可作为GD的临床诊断、治疗以及疾病转归的参考指标。  相似文献   

2.
The work showed a phenomenon of influence of seismic and resonance shock waves on the long-range order in a liquid. On examples of damage of ion pair solvated clusters in aqueous solutions of NaCl (3.5 wt%), HCl (2 wt%), AgNO3 (1.7 wt%) and molecular bunches (clusters) in distilled water placed to laboratory chemical reactor far distant from the epicenters of earthquakes the relations between incoming shock and seismic waves and instability of cluster and supracluster long range organization (molecular bunches assocoates) in a liquid is demonstrated. Understanding of risks for chemical industry both in respect of quality and chemical processes instability, and in respect of loose control over chemical technology is considered. Examples of changes in internal organization of solutions in the period of strong hurricane in Europe at February 17, 2007, strong earthquake in Japan at March 25, 2007 and a series of earthquakes at April 4 to 9, 2007 are given and the phenomenon is explained. The risks for chemical industry and the chances of practical using the phenomenon are considered. The clusters in liquids show different responses to the processes in the disaster epicenter, and their responses can be used for understanding chemical processes in Earth crust and in the centers of hurricanes and for strategy of disposing and protecting chemical facilities.  相似文献   

3.
betaig-h3 is a TGF-beta-induced extracellular matrix protein which is expressed in many tissues including bones and cartilages. In previous reports, we showed that betaig-h3 mediates cell adhesion and migration and, especially in bones, negatively regulates the mineralization in the end stage of endochondral ossification. Here, to elucidate the expression pattern and role of betaig-h3 in chondrocyte differentiation, ATDC5 chondrocytes and embryonic and postnatal mice were used for in vitro differentiation studies and in vivo studies, respectively. betaig-h3 was strongly induced by the treatment of TGF-beta1 and the expression level of betaig-h3 mRNA and protein were highly expressed in the early stages of differentiation but decreased in the late stages in ATDC5. Furthermore, the patterns of TGF-beta1, -beta2, and -beta3 mRNA expression were concurrent with betaig-h3 in ATDC5. betaig-h3 was deeply stained in perichondrium (PC), periosteum (PO), and prehypertrophic chondrocytes (PH) through the entire period of endochondral ossification in mice. betaig-h3 was mainly expressed in PC and PH at embryonic days and obviously in PH in postnatal days. These results suggest that betaig-h3 may play a critical role as a regulator of chondrogenic differentiation in endochondral ossification.  相似文献   

4.
用原子吸收光谱法测定延边地区317名65~108岁老人头发中锌、铜、铁、锰、镁含量,观察不同民族、性别、年龄老人这些元素的差异。结果表明:1.朝鲜旗发锌低于汉族,满族发铜低于汉族、朝鲜族,汉族发镁高于朝鲜族、满族,发铁、发锰在汉、朝、满民族之间无区别。2.汉族、朝鲜族男发锌高于女性,汉族女性发铜高于男性,发铁、发锰、发镁在性别之间无区别。3、90岁组朝鲜族发锰、发镁低于65岁、76岁组,朝鲜族发锌、发铜、发铁在65~108岁之间无统计学意义。  相似文献   

5.
Studies performed on the interactions and reactions of compounds in the bidimensional state, essentially in monolayers and Langmuir-Blodgett multilayers, with substances in the aqueous subphase are reported. More precisely, the following is illustrated: (i) interactions between acid amphiphiles and prevalently bivalent ions placed in the aqueous support and between compounds capable of functioning like ion carriers in monolayers and ions in the subphase, in order to build mimetic membranes capable of selective ion transport; and the complexation of amphiphiles in monolayer with ions in the bulk liquid phase, in order to build chemical sensors to ions; (ii) the reactions of photoinduced electron transfer between a partner in mono- or multimolecular films and a partner in the subphase, which may determine the fundamental parameters and the differences with the same reactions in the bulk phase; and (iii) the reactions of enzymatic hydrolysis between the monolayer of a glyceride, which constitutes the reaction support, and the enzyme in the liquid bulk phase, which constitutes the subphase. The mechanism of the reactions and its inhibition are clarified. To conclude, possible future developments connected with the areas studied are examined.  相似文献   

6.
Near-infrared and ultraviolet absorption of water-benzene mixtures has been measured at temperatures and pressures in the ranges of 323-673 K and 50-400 bar, respectively. Concentrations of water and benzene in both the water-rich phase and the benzene-rich phase of the mixtures were obtained from absorption intensities of near-infrared bands of water and benzene and ultraviolet bands of benzene. Mutual solubilities in molar fractions increase remarkably with increasing temperature at pressures in the two-liquid-phase coexistence region, and are consistent with previously reported values. It proves that the solubility of benzene in water is an order of magnitude smaller than that of water in benzene throughout the two-phase region. In addition, it is found that effect of pressure on the solubilities is opposite between water in benzene and benzene in water. These solubility properties are discussed on the basis of a cavity-based solvation model. It is suggested that the asymmetry in the mutual solubility and the opposite direction of the pressure effect are caused by difference in molecular size and difference in thermal compressibility, respectively, between water and benzene.  相似文献   

7.
A high cholesterol/cholate diet induced hypercholesterolemia and fatty liver in both spontaneously hypertensive rats (SHR) and normotensive control rats (WKY). However, in contrast to previous concepts, the levels of cholesterol ester, triacylglycerol and phosphatidylcholine in plasma as well as triacylglycerol in liver were higher in WKY than in SHR fed a normal diet. The high cholesterol/cholate diet elevated the levels of plasma cholesterol, plasma cholesterol ester and hepatic triacylglycerol, and the extent of elevation was significantly higher in WKY than in SHR. Increases both in monoene/saturated ratios, an indication of elevated delta 9-desaturase activity, and in linoleate/arachidonate ratios, a possible indication of impaired desaturation-elongation activity, were observed in hepatic and plasma lipids of both strains fed the high cholesterol/cholate diet. The increases in monoene/saturated ratios were similar in both strains, but the increases in the linoleate/arachidonate ratios were higher for the plasma cholesterol esters of WKY than of SHR. The n-6/n-3 ratios of plasma and hepatic lipids were higher in WKY than in SHR throughout the experiments. These diet-induced changes observed in hepatic and plasma lipids were not reflected in the aortic lipids. Thus, hypertension per se does not promote the development of hyperlipemia and fatty liver induced by a high cholesterol/cholate diet. Our results also suggest that the metabolism of polyenoic fatty acids is different between SHR and WKY.  相似文献   

8.
We have investigated the tumour-localising properties and in vivo fluorescence kinetics of a hexamethoxylated carotenqporphyrin (CP6) in two primary tumour models: UV-B-induced early skin cancer in hairless mice and chemically induced mucosal dysplasia in the rat palate. CP6 fluorescence kinetics are investigated by measuring in vivo fluorescence spectra and images of the mouse skin and the rat palate at different time points after injection. For the tumour-localising properties, microscopic phase-contrast and fluorescence images are recorded. The in vivo fluorescence kinetics in the mouse skin show localization of CP6 in the tumours. However, fluorescence microscopy images show that CP6 localises in the dermis and structures that are not related to the malignant transformation of the mouse skin. The fluorescence kinetics in the rat palate show a significant correlation between the degree of malignancy and the CP6 fluorescence build-up time in the palate. The microscopic images show that CP6 fluorescence localises in the connective tissue and not in the dysplastic epithelium. In conclusion, CP6 does not localise preferentially in (pre-) cancerous tissue in the two primary tumour models studied here, in contrast to reports about localisation of carotenoporphyrins in transplanted tumours. However, the CP6 build-up time in rat palates correlates with the degree of malignancy and this might possibly be a useful parameter in tumour detection.  相似文献   

9.
The amount of free and bound sterols and triterpenoids in the leaf blades and petioles of the variety Tashkent-1 and the deciduous lines L-275 and L-470 in the budding-flowering, maturing, and leaf-fall phases have been compared. In the leaf blades, the maximum accumulation of free sterols in the deciduous lines is observed in an earlier phase than in the variety Tashkent-1, and this is most characteristic for sterols saturated in the C-17 side chain. The dynamics of the change in the content of unsaturated sterols is individual for each line. The nature of the change in the amount of free sterols in the petioles is typical for each line and does not depend on the nature of the sterol for the variety Tashkent-1 this index falls sharply in the leaf-fall phase while for L-275 the process is retarded between the second and third phases, and for L-470 in the same period the amount of these substances rises sharply. In the leaf blades, as a rule, the level of sterol esters changes in parallel with the levels of free sterols, and in the petioles in the antiparallel direction between the first and second phases. In all the samples free and bound amyrin was detected. The dynamics of the change in the amounts of these substances in the three lines were different. Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Institute of Experimental Plant Biology, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, Vol. 6, pp. 796–805, November–December, 1989.  相似文献   

10.
The amount of free and bound sterols and triterpenoids in the leaf blades and petioles of the variety Tashkent-1 and the deciduous lines L-275 and L-470 in the budding-flowering, maturing, and leaf-fall phases have been compared. In the leaf blades, the maximum accumulation of free sterols in the deciduous lines is observed in an earlier phase than in the variety Tashkent-1, and this is most characteristic for sterols saturated in the C-17 side chain. The dynamics of the change in the content of unsaturated sterols is individual for each line. The nature of the change in the amount of free sterols in the petioles is typical for each line and does not depend on the nature of the sterol for the variety Tashkent-1 this index falls sharply in the leaf-fall phase while for L-275 the process is retarded between the second and third phases, and for L-470 in the same period the amount of these substances rises sharply. In the leaf blades, as a rule, the level of sterol esters changes in parallel with the levels of free sterols, and in the petioles in the antiparallel direction between the first and second phases. In all the samples free and bound amyrin was detected. The dynamics of the change in the amounts of these substances in the three lines were different.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Institute of Experimental Plant Biology, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, Vol. 6, pp. 796–805, November–December, 1989.  相似文献   

11.
Infrared spectra in the NH, OH, and C?O stretching regions are reviewed for various methylated and halogenated 2(4)-oxopyrimidines and uracils, as well as other nucleic acid derivatives, in the vapor phase and in low-temperature matrices. The 2-oxopyrimidines are predominantly in the enol form both in the vapor phase and in low-temperature matrices. By contrast, the 4-oxopyrimidines exhibit comparable populations of the keto and enol forms, with KT ≈ 1–2, and a difference in chemical binding energy between the two forms in the gaseous phase of the order of 1–2 kcal/mol. The observed tautomeric equilibria in the gas phase point to the need for a drastic revision of interpretations of theoretical methods, and simultaneously provide the appropriate quantitative data necessary for testing the results of quantum mechanical calculations. In sharp contrast to other heterocyclic systems, several of the bases found in natural nucleic acids were found to exist predominantly in the keto or amino forms, as in the solution phase. In particular, uracils exist predominantly in the keto form. This has made possible, for this class of compounds, to evaluate the heats of sublimation and vaporization, and to relate these data to hydrogen bonding and stacking interactions in the condensed phases. Examples are presented of base analogs which do exhibit appreciable tautomerism in solution. Some biological implications of the foregoing are presented in relation to the types of heterocyclic bases found in natural nucleic acids, and to concepts of spontaneous and induced mutagenesis.  相似文献   

12.
中国煤中铍的分布赋存特征研究   总被引:2,自引:3,他引:2  
根据对中国不同矿区1018个煤层煤样和生产煤样铍含量数据的统计结果,分析了中国不同成煤时代、不同聚煤区煤中铍的分布特征。同时,根据对10个不同煤田煤样的实验室浮沉试验、煤岩分析等试验研究,运用Solari方法,计算了煤中各组分中铍的理论含量,讨论了中国煤中铍的赋存特征,尤其是铍在各种煤岩组分中的分布。研究表明,铍在煤中富集程度较高,但相对于世界煤中平均水平来说,中国煤中铍含量总体水平较低。煤中铍主要赋存于惰质组及伊利石粘土矿物中,在镜质组及其它矿物中含量较低。同时,中国大多数煤中铍的有机亲和性指数较高,不利于选煤过程中铍的脱除。  相似文献   

13.
An analytical method was established for the simultaneous determination of 39 polycyclic aromatic hydrocarbons (PAHs) in air. The method was applied to a survey of gaseous and particulate PAHs in household indoor air. The survey was performed in 21 houses in the summer of 1999 and in 20 houses in the winter of 1999-2000 in Fuji, Japan. Thirty-eight PAHs were determined in indoor and outdoor air in the summer, and 39 PAHs were determined in indoor and outdoor air in the winter. The concentrations of gaseous PAHs in indoor air tended to be higher than those in outdoor air in the summer and winter. The concentrations of particulate PAHs in indoor air were the same as or lower than those in outdoor air in the summer and winter. PAH profiles, correlations between PAH concentrations, and multiple regression analysis were used to determine the factors affecting the indoor PAH concentrations. These results showed that gaseous PAHs in indoor air were primarily from indoor emission sources, especially during the summer, and that indoor particulate PAH concentrations were significantly influenced by outdoor air pollution.  相似文献   

14.
Usually neutron activation analyses are performed in point-source geometry. However, specially designed irradiation positions and carefully planned measuring conditions enabled the activation and analysis of samples with weights up to several tens of kilograms. A dedicated character of irradiation and of measuring conditions was the main reason for a very limited application of such activation analysis. The use of routine irradiation facilities and standard conditions for analytical gamma-spectrometric measurements is described. Starting with samples of some hundred milligrams usually used in activation, through multi-gram samples to several hundred gram samples, irradiation and measuring conditions were studied and tested for development of the method. This work began in 1991 in Denmark, using the Danish DR-3 reactor. Since then different aspects of the method have been investigated on 6 reactors; in Denmark on DR-3, in Austria on Triga-MkII (in Vienna), and Astra (in Seibersdorf), in the German Federal Republic on FRG-1 in Geesthacht, in Norway on Jeep II (in Kjeller), and in Kazakhstan on VVR-K (in Alatau). Altogether more than 1000 samples have been irradiated and measured. In total, the roughly 30 kg of irradiated materials included almost 300 large samples of more than 30 gram weight. The following theoretical and practical aspects were investigated during the work: theoretical problems concerning neutron self-absorption in common organic and inorganic materials, as well as gamma-attenuation during the measurement. From a more practical point of view: health physics and radiation hazards during irradiation, measurement, transportation and storage of samples with several hundred grams weight. Special requirements to irradiation containers were formulated and various containers were tested. Main advantages and drawbacks of the method are discussed.  相似文献   

15.
Porphyrins and metalloporphyrins fulfil a very important role in the metabolism of living organisms through biological pigments or biochromes and are therefore also employed in numerous applications in analytical chemistry. In flow-injection analysis the role of porphyrins and metalloporphyrins are centered as either that of analyte or that of a reagent or modifier in the determination of other species. This paper covers the attributes of porphyrin and metallophorphyrin complexes as enhancements in chemical analysis in flow-injection systems and points out the advantages and disadvantages in the implementation thereof.  相似文献   

16.
We developed a sandwich enzyme-linked immunosorbent assay (ELISA) system for calphobindin I (CPB-I), a new placental coagulation inhibitor, using two monoclonal antibodies. This ELISA system can detect CPB-I at concentrations of between 0.4 and 25 ng/ml in buffer and allow almost quantitative determination of it in human plasma. Using this ELISA system, CPB-I levels in many kinds of specimens were measured. Levels in the plasma and urine of women were as low as 10 ng/ml, and no significant differences were observed throughout the trimesters of pregnancy and during different stages of the menstrual cycle. Toxemic patients were slightly higher in CPB-I levels than normal pregnant women, and levels in body fluids such as the amniotic fluid, saliva, milk, ascites, and semen were higher than those in the plasma. The high levels of CPB-I were found, being in the order of micrograms/ml, in the ascites of carcinomatous peritonitis as well as seminal plasma. Measurements of the levels in ovarian follicular fluid samples at different stages of the menstrual cycle showed that those in the immature and atretic stages were higher than those in mature stages. CPB-I levels in many types of cultured human cells ranged from 0.023 to 10.30 micrograms/mg protein, and levels in cultured human lymphocytes were less than those in other types of cells measured. Little of this inhibitor was secreted into media from cultured human lymphocytes, and it was found in all measured tissues of Macacus irus at levels ranging from 0.232 to 1.557 micrograms/mg protein. From these results, it was suggested that CPB-I might be a ubiquitous protein in the body that has an important physiological role.  相似文献   

17.
The accelerated growth of aquaculture has resulted in a series of harmful effects to human health. The widespread and unrestricted use of antibiotics in this industry, to prevent bacterial infections, leads to remaining amounts in the aquatic environment. This has resulted in the emergence of antibiotic-resistant bacteria in aquaculture environments, in the increase in antibiotic resistance in fish pathogens as well as in the transfer of these resistance determinants to human pathogens. Moreover, the use of large amounts of antibiotics may lead to the presence of residual antibiotics in fish tissue and fish products. Fluoroquinolones, tetracyclines, penicillins, sulphonamides and other antibiotics, exhibiting activity against both Gram-positive and Gram-negative bacteria, are widely used for the treatment and prevention of diseases in fish. An extended and comprehensive review on the recent analytical methodologies concerning antibiotic residues in fish reported in the literature is provided in the present article. Emphasis is given on sample preparation regarding isolation and purification, chromatographic conditions and method validation according to legislation. Results of published assays are comparatively presented and criticised.  相似文献   

18.
The purpose of this review is to present an overview of the development of photodiagnostic and photodynamic therapy (PDD and PDT) techniques in Poland. The paper discusses the principles of PDD, including fluorescent techniques in determining precancerous conditions and cancers of the skin, digestive tract, bladder and respiratory tract. Methods of PDT of cancer will be discussed and the current state of knowledge as well as future trends in the development of photodynamic techniques will be presented, including the possibility of using photodynamic antimicrobial therapy. Research pioneers in photodynamic medicine such as Thomas Dougherty are an inspiration for the development of methods of PDD and PDT in our Clinic. The Center for Laser Diagnostics and Therapy in Bytom, Poland, promotes the propagation of PDD and PDT through the training of clinicians and raising awareness among students in training and the general public. Physicians at the Center are engaged in photomedical research aimed at clinical implementation and exploration of new avenues in photomedicine while optimizing existing modalities. The Center promotes dissemination of clinical results from a wide range of topics in PDD and PDT and serving as representative authorities of photodynamic medicine in Poland and Europe.  相似文献   

19.
Mammalian cell surfaces are modified with complex arrays of glycans that play major roles in health and disease. Abnormal glycosylation is a hallmark of cancer; terminal sialic acid and fucose in particular have high levels in tumor cells, with positive implications for malignancy. Increased sialylation and fucosylation are due to the upregulation of a set of sialyltransferases (STs) and fucosyltransferases (FUTs), which are potential drug targets in cancer. In the past, several advances in glycostructural biology have been made with the determination of crystal structures of several important STs and FUTs in mammals. Additionally, how the independent evolution of STs and FUTs occurred with a limited set of global folds and the diverse modular ability of catalytic domains toward substrates has been elucidated. This review highlights advances in the understanding of the structural architecture, substrate binding interactions, and catalysis of STs and FUTs in mammals. While this general understanding is emerging, use of this information to design inhibitors of STs and FUTs will be helpful in providing further insights into their role in the manifestation of cancer and developing targeted therapeutics in cancer.  相似文献   

20.
Metabolomics and lipidomics have demonstrated increasing importance in underlying biochemical mechanisms involved in the pathogenesis of diseases to identify novel drug targets and/or biomarkers for establishing therapeutic approaches for human health. Particularly, bioactive metabolites and lipids have biological activity and have been implicated in various biological processes in physiological conditions. Thus, comprehensive metabolites, and lipids profiling are required to obtain further advances in understanding pathophysiological changes that occur in cells and tissues. Chirality is one of the most important phenomena in living organisms and has attracted long-term interest in medical and natural science. Enantioselective separation plays a pivotal role in understanding the distribution and physiological function of a diversity of chiral bioactive molecules. In this context, it has been the goal of method development for targeted and untargeted metabolomics and lipidomic assays. Herein we will highlight the benefits and challenges involved in these stereoselective analyses for clinical samples.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号