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1.
Insulin-like growth factor (IGF)/IGF binding protein (IGFBP) abnormalities may be important in the pathogenesis of growth failure in chronic renal failure (CRF). We induced experimental CRF by 5/6 nephrectomy in Sprague Dawley rats (100 g) and observed for 2 weeks comparing with sham-operated pair-fed control rats (Sham- C). CRF rats gained 30% less height than Sham- C rats (P < 0.01). Serum IGFBP profiles by Western ligand blot revealed that IGFBP4 was elevated two fold in CRF rats (P < 0.01 vs. Sham-C). However, IGFBP4 mRNA levels in liver or skeletal muscle were not different in two groups. To determine if the increase of serum IGFBP4 in CRF retarded the growth of cartilage, epiphyseal chondrocytes were isolated from CRF or control rats and cultured in the presence of control or CRF rat sera. Incubation with 10% CRF serum reduced proliferations of normal chondrocytes and L6 rat skeletal muscle cells. In contrast, 10% CRF serum did not inhibit the growth of CRF chondrocytes. Rat sera from two groups were separated into two different fractions, high (>10 kDa, containing IGFBPs) and low (<10 kDa, containing free IGF) molecular weight fractions using a gel filtration column. Both fractions obtained from CRF sera decreased the growth of control chondrocytes up to 40% compared with those from control sera. We suggest that the pathogenesis of growth failure in CRF may be involved in the increase of circulating IGFBP4 as well as the unidentified small molecular weight uremic serum factors which block the growth of chondrocytes in growth plate.  相似文献   

2.
The chemical composition of extractives in the sapwood (SW), heartwood (HW), knotwood (KW), and branchwood (BW of silver fir (Abies alba Mill.) was analyzed, and their antifungal and antioxidant properties were studied. In addition, the variability of extractives content in a centripetal direction, i.e., from the periphery of the stem towards the pith, was investigated. The extracts were analyzed chemically with gravimetry, spectrophotometry, and chromatography. The antifungal and antioxidative properties of the extracts were evaluated by the agar well diffusion method and the diphenyl picrylhydrazyl radical scavenging method. Average amounts of hydrophilic extractives were higher in KW (up to 210.4 mg/g) and BW (148.6 mg/g) than in HW (34.1 mg/g) and SW (14.8 mg/g). Extractives identified included lignans (isolariciresinol, lariciresinol, secoisolariciresinol, pinoresinol, matairesinol) phenolic acids (homovanillic acid, coumaric acid, ferulic acid), and flavonoids epicatechin, taxifolin, quercetin). Secoisolariciresinol was confirmed to be the predominant compound in the KW (29.8 mg/g) and BW (37.6 mg/g) extracts. The largest amount of phenolic compounds was extracted from parts of knots (281.7 mg/g) embedded in the sapwood and from parts of branches (258.9 mg/g) adjacent to the stem. HW contained more lignans in its older sections. Hydrophilic extracts from knots and branches inhibited the growth of wood-decaying fungi and molds. KW and BW extracts were better free radical scavengers than HW extracts. The results of the biological activity tests suggest that the protective function of phenolic extracts in silver fir wood can also be explained by their antioxidative properties. The results of this study describe BW as a potential source of phenolic extractives in silver fir.  相似文献   

3.
Genetic polymorphisms may be linked to inter-individual differences in erythropoietin (EPO) resistance. We investigated the -511C/T polymorphism of the IL-1B gene and the I/D polymorphism of the ACE gene for any association with EPO resistance index (ERI) in maintenance hemodialysis patients (n=167). Because EPO responsiveness is multi-factorial, we also included other possible influences (age, sex, time on dialysis, ACE inhibitor or angiotensin receptor blocker use, ferritin, transferrin saturation, intact PTH, high sensitivity C-reactive protein, albumin, Kt/V, and presence of diabetes mellitus) on ERI in our analyses. Multiple regression analysis showed significant association of the IL-1B-511CC and ACE DD polymorphisms with ERI (P=0.038 and P=0.004 in the recessive model, respectively). The combination (C) of alleles of two loci showed that C1 (I-T) was significantly associated with ERI in the co-dominant and recessive models (P=0.005 and P=0.0001, respectively). Subjects who did not carry C1 showed significantly decreased ERI (10.10+/-5.15 IU/kg weight/g hemoglobin) compared to other study subjects (C1/C1 and C1/-; 12.97+/-4.90 and 15.12+/-7.43 IU/kg weight/g hemoglobin, respectively). Our study indicates that the IL-1B-511C/T and ACE I/D polymorphisms may be useful genetic markers of EPO requirement in hemodialysis patients. These findings might also provide a new perspective on therapeutic approaches to the treatment of end stage renal disease patients with anemia.  相似文献   

4.
Infrared spectrum and bonding in uranium methylidene dihydride, CH2=UH2   总被引:1,自引:0,他引:1  
Uranium atoms activate methane upon ultraviolet excitation to form the methyl uranium hydride CH3-UH, which undergoes alpha-H transfer to produce uranium methylidene dihydride, CH2=UH2. This rearrangement most likely occurs on an excited-quintet potential-energy surface and is followed by relaxation in the argon matrix. These simple U+CH4 reaction products are identified through isotopic substitution (13CH4, CD4, CH2D2) and density functional theory frequency and structure calculations for the strong U-H stretching modes. Relativistic multiconfiguration (CASSCF/CASPT2) calculations substantiate the agostic distorted C1 ground-state structure for the triplet CH2=UH2 molecule. We find that uranium atoms are less reactive in methane activation than thorium atoms. Our calculations show that the CH2=UH2 complex is distorted more than CH2=ThH2. A favorable interaction between the low energy open-shell U(5f) sigma orbital and the agostic hydrogen contributes to the distortion in the uranium methylidene complexes.  相似文献   

5.
The isotopomeric complexes trans-W(Cmesityl)[(C(H,D)3)2PCH2CH2P(C(H,D)3)2]2(H,D) 1-4 were prepared. 2 (W(Cmesityl)(dmpe)2D) was used to study the Deuterium Quadrupole Coupling Constant (DQCC) and the ionicity of the W-D bond (DQCC=34.1 kHz; ionicity 85%). 1 (W(Cmesityl)(dmpe)2H) shows several dynamic exchange processes in solution, such as HW/HW, HW/ortho-Memesityl, and HW/H2 exchanges observed by NMR in combination with deuterium labeling studies and double label crossover experiments. Except for the HW/H2, these reactions comprise elementary steps, which also appear along the isomerization pathway of 1 into (2,3,5-trimethylphenylcarbyne)(dmpe)2WH (5) at 60 degrees C. 5 was characterized by an X-ray diffraction study. In the solid state only an HW/Mep exchange process prevails appearing at higher temperatures, which was identified by NMR and by Quasielastic Neutron Scattering. The latter also provided an activation barrier of 5 kcal/mol and a "jump width" for the moving H nucleus in agreement with the HW...Mep distance of the X-ray diffraction study of 1.  相似文献   

6.
《Electrophoresis》2018,39(4):569-580
A fast and precise affinity capillary electrophoresis (ACE) method has been applied to investigate the interactions between two serum albumins (HSA and BSA) and heparinoids. Furthermore, different free flow electrophoresis methods were developed to separate the species which appears owing to interaction of albumins with pentosan polysulfate sodium (PPS) under different experimental conditions. For ACE experiments, the normalized mobility ratios (∆R/Rf), which provided information about the binding strength and the overall charge of the protein‐ligand complex, were used to evaluate the binding affinities. ACE experiments were performed at two different temperatures (23 and 37°C). Both BSA and HSA interact more strongly with PPS than with unfractionated and low molecular weight heparins. For PPS, the interactions can already be observed at low mg/L concentrations (3 mg/L), and saturation is already obtained at approximately 20 mg/L. Unfractionated heparin showed almost no interactions with BSA at 23°C, but weak interactions at 37°C at higher heparin concentrations. The additional signals also appeared at higher concentrations at 37°C. Nevertheless, in most cases the binding data were similar at both temperatures. Furthermore, HSA showed a characteristic splitting in two peaks especially after interacting with PPS, which is probably attributable to the formation of two species or conformational change of HSA after interacting with PPS. The free flow electrophoresis methods have confirmed and completed the ACE experiments.  相似文献   

7.
Ammonia molecules interact with U atoms, and the resulting U:NH3 complex rearranges upon visible irradiation to form the H2N--UH and HN==UH2 molecules in excess argon. These products are identified by functional group frequencies, 15NH3 and ND3 isotopic shifts, and comparison to frequencies calculated by using density functional theory. The N==U pi bond in HN==UH2 is enhanced by partial triple-bond character through N(2p) to U(5f) conjugation, which is comparable to that found in the analogous HN==ThH2 molecule. These products also form complexes with additional ammonia molecules in the matrix. The interesting higher-energy N[triple chemical bond]UH3 complex is not formed.  相似文献   

8.
The thermal stability of wood polymer composites made with extractive-free wood from four different wood species was studied. Hot water (HW) extractives, ethanol/cyclohexane (E/C) extractives and both types of extractives were eliminated from A. cyclops, E. grandis, P. radiata and Q. alba. Composites of LLDPE and 10 wt% of wood were prepared, using poly vinyl alcohol-co-ethylene (EVOH) as a compatibilizer. The thermal degradation behavior of the composites was characterized with thermogravimetric analysis (TGA). The obtained results showed that in all cases, the degradation temperatures shifted to higher values after removal of the extractives. The removal of E/C extractives was less effective in its improvement of the thermal stability than the removal of HW extractives. The largest improvement on the thermal stability of WPCs was achieved when both types of extractives (E/C and HW) were removed.  相似文献   

9.
Transforming growth factor-beta1 (TGF-beta1) can act as both a tumor suppressor and a stimulator of tumor progression. We have examined the relationship between polymorphisms of the TGF-beta1 gene and the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B virus (HBV) infection. A total of 1,237 Korean subjects were prospectively enrolled; 1,046 patients with chronic HBV infection and 191 healthy controls with no evidence of recent or remote HBV infection. The patients were divided into two groups: those without (n = 809) and those with HCC (n = 237). Single nucleotide polymorphisms (SNPs) of TGF-beta1 were searched for and genotyped using the single base extension method. In Korean subjects, only two SNPs were found among the seven known polymorphisms of TGF-beta1, at position -509 and in codon 10. The risk of HCC was significantly lower in patients with the T/T or C/T genotypes than in those with the C/C genotypes at position -509 (P < 0.02), and also lower among those with the Pro/Pro or Leu/Pro genotypes than in those with the Leu/Leu genotypes in codon 10 (P < 0.007). Haplotype analysis revealed that the possession of [-509C > T; L10P] conferred a decreased likelihood of HCC (OR = 0.74; 95% CI, 0.59-0.93; P = 0.008). In conclusion, the presence of the TGF-beta1 -509C > T promoter or of the L10P polymorphism, and the combination of both [-509C > T; L10P] as a haplotype were strongly associated with a reduced risk of HCC in patients with chronic HBV infection.  相似文献   

10.
The U4+ mixed alkyl hydride complex (C5Me5)U[mu-C5Me3(CH2)2](mu-H)2U(C5Me5)2, 1, which contains a cyclopentadienyl ligand with two metalated methylene substituents, can effect four, six, and eight-electron reductions in which the combination of the two H1- ligands and the [C5Me3(CH2)2]3- moiety delivers four electrons and forms (C5Me5)1-. The reaction is formally equivalent to an alkyl hydride reductive elimination, a transformation common with transition metals not previously observed with f element compounds. This type of alkyl hydride reduction reactivity is also observed with a combination of U4+ alkyl and hydride complexes, (C5Me5)2UMe2/[(C5Me5)2UH2]2, which reduces benzene to make [(C5Me5)2U]2(C6H6), a U3+ complex formally containing a (C6H6)2- ligand.  相似文献   

11.
Parathyroid hormone (PTH) treatment was previously shown to improve cardiac function after myocardial infarction by enhancing neovascularization and cell survival. In this study, pressure overload-induced left ventricular hypertrophy (LVH) was induced in mice by transverse aortic banding (TAB) for 2 weeks. We subsequently evaluated the effects of a 2-week treatment with PTH or saline on compensated LVH. After another 4 weeks, the hearts of the mice were analyzed by echocardiography, histology, and molecular biology. Echocardiography showed that hearts of the PTH-treated mice have more severe failing phenotypes than the saline-treated mice following TAB with a greater reduction in fractional shortening and left ventricular posterior wall thickness and with a greater increase in left ventricular internal dimension. Increases in the heart weight to body weight ratio and lung weight to body weight ratio following TAB were significantly exacerbated in PTH-treated mice compared to saline-treated mice. Molecular markers for heart failure, fibrosis, and angiogenesis were also altered in accordance with more severe heart failure in the PTH-treated mice compared to the saline-treated mice following TAB. In addition, the PTH-treated hearts were manifested with increased fibrosis accompanied by an enhanced SMAD2 phosphorylation. These data suggest that the PTH treatment may accelerate the process of decompensation of LV, leading to heart failure.  相似文献   

12.
The thermodynamic hydride donor abilities of [HW(CO)(5)](-) (40 kcal/mol), [HW(CO)(4)P(OMe(3))](-) (37 kcal/mol), and [HW(CO)(4)(PPh(3))](-) (36 kcal/mol) have been measured in acetonitrile by either equilibrium or calorimetric methods. The hydride donor abilities of these complexes are compared with other complexes for which similar thermodynamic measurements have been made. [HW(CO)(5)](-), [HW(CO)(4)P(OMe(3))](-), and [HW(CO)(4)(PPh(3))](-) all react rapidly with [CpRe(PMe(3))(NO)(CO)](+) to form dinuclear intermediates with bridging formyl ligands. These intermediates slowly form [CpRe(PMe(3))(NO)(CHO)] and [W(CO)(4)(L)(CH(3)CN)]. The structure of cis-[HW(CO)(4)(PPh(3))](-) has been determined and has the expected octahedral structure. The hydride ligand bends away from the CO ligand trans to PPh(3) and toward PPh(3).  相似文献   

13.
Addition of 2 equiv of I2 to a stirring suspension of UH3 in Et2O results in vigorous gas evolution and the formation of UI4(OEt2)2 (1), which can be isolated in good yields as an air- and moisture-sensitive brick-red powder. Addition of 3 equiv of AgBr to UH3 in DME produces UBr3(DME)2 (2), while addition of 4 equiv of AgX to UH3 in DME-CH2Cl2 provides UX4(DME)2 (X = Br, 3; Cl, 4). Similarly, the reaction of 4 equiv of AgOTf with UH3 in neat DME generates U(OTf)4(DME)2 (5). Each of these reactions proceeds with the evolution of hydrogen. Complex can also be generated by reaction of 4 equiv of Me3SiI with UCl4 in Et2O. All complexes were fully characterized, including analysis by X-ray crystallography.  相似文献   

14.
In this study, the effects of ultrasound on ozone treatment processes for bleaching cotton fabrics were investigated and compared with the conventional hydrogen peroxide bleaching process (60 °C over 90 min). Two ultrasonic + ozone treatments of cotton fabric samples were carried out: (1) ozone in an ultrasonic homogenizer (UH) and (2) ozone in an ultrasonic bath. Ozone dosages, temperature and time variations were determined with both ozone-ultrasonic bleaching processes. Whiteness, yellowness, weight, tensile strength properties, FTIR (ATR) spectra and visual appearance, via scanning electron microscopy of treated cotton fabrics as well as chemical oxygen demand (COD) of bleaching effluents, were investigated. It was concluded that the ozone + UH process, conducted for 30 min at 30 °C, produced closely equivalent values of cotton fabric whiteness and yellowness to the classic peroxide bleaching process, with slightly less weight loss, dramatically less COD in the process effluent (29 mg/l for ozone-UH vs. 4,316 mg/l for classical peroxide treatment), and without causing any adverse and/or detrimental effects on loss of fabric strength or elongation of the cotton fabrics. The ozone-UH process also leads to time and energy savings with much less environmental impact. Consequently, the combination of ozonation plus UH carried out at 30 °C over 30 min can be used successfully for cotton bleaching instead of the classic hydrogen peroxide bleaching process.  相似文献   

15.
Four 3-deaza analogues of the potent anticonvulsant purine, BW A78U, were synthesized and tested for anticonvulsant activity. The imidazo[4,5-c]pyridines 9–12 were prepared in two steps from 4-chloro-1H-imidazo[4,5-c]pyridine ( 2 ). The compounds were potent anticonvulsant agents against maximal electroshock-induced seizures in rats with i.p. ED50 ranging from 2 to 3.5 mg/kg. However, these 3-deazapurines were appreciably more toxic than BW A78U, which precluded their development as potential antiepileptic agents.  相似文献   

16.
Uncaria Hook (UH) alkaloids are involved in the beneficial effects of Yokukansan. However, the pharmacokinetics of UH alkaloids after oral administration of Yokukansan has not yet been sufficiently investigated. Therefore, we developed and validated a sensitive and specific high‐performance liquid chromatography with tandem mass spectrometry (LC/MS/MS) method for the simultaneous quantitation of seven UH alkaloids (corynoxeine, isocorynoxeine, rhynchophylline, isorhynchophylline, hirsutine, hirsuteine and geissoschizine methyl ether) in rat plasma and brain. After protein precipitation with acetonitrile, chromatographic separation was performed using an Ascentis Express RP‐amide column, with gradient elution with 0.2% formic acid and acetonitrile at 0.3 mL/min. All analytes in the plasma and brain showed good linearity over a wide concentration range (r > 0.995). Intra‐day and inter‐day variations of each constituent were 8.6 and 8.0% or less in the plasma, and 14.9 and 15.0% or less in the brain, respectively. The validated LC/MS/MS method was applied in the pharmacokinetic studies of UH alkaloids after oral administration of Yokukansan to rats. In the plasma, rhynchophylline, hirsutine, hirsuteine and geissoschizine methyl ether were detected, but only geissoschizine methyl ether was detected in the brain. These results suggest that geissoschizine methyl ether is an important constituent of the pharmacological effects of Yokukansan. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

17.
Cardiomyocyte hypertrophy is a major cause of morbidity and mortality worldwide. The aim of this study is to determine the effects of sodium tanshinone IIA sulfonate (STS) on cardiomyocyte hypertrophy induced by angiotensin II (Ang II) in vivo and in vitro. In long-term treatment, adult Wistar rats were infused with Ang II for three weeks via osmotic mini-pumps and some of them were given intragastrically of STS. Left ventricle was isolated; the ratio of left ventricular weight to body weight and systolic blood pressure (SBP) were determined and heart morphometry was assessed after hematoxylin and eosin staining. Results indicated STS inhibited Ang II-induced increases in myocyte diameter and decreased the LVW/BW ratio independent of decreasing systolic blood pressure. In vitro, treatment of cultured cardiomyocytes with STS inhibited Ang II-induced increase in cell size, protein synthesis, ANP expression, activation of extracellular signal- regulated kinase (ERK) and ERK kinase (MEK). Then we reexamined the mechanism of STS-induced anti-hypertrophic effects. Results revealed MEK inhibitor U0126 (20 microM) markedly enhanced STS-induced depressions in [(3)H]leucine incorporation and ANP expression. In conclusion, MEK/ERK pathway plays a significant role in the anti-hypertrophic effects of STS.  相似文献   

18.
1.  Diastereomeric complexes of - and -bis-[N-salicylidene-S-alaninato]chromate(III)K and - and -bis-[N-salicylidene-S-valinato]chromate(III)K were synthesized and chromatographically separated. The absolute configuration of the diastereomers was demonstrated with the aid of ORD curves.
2.  The kinetics of the epimerization of - and -bis-[N-salicylidene-S-alaninato]chromate(III)K and - and -bis-[N-salicylidene-S-valinato]chromate(III)K under the action of OH ions in water was studied: it was shown that the proton of the amino acid fragment is less labile in these complexes than in the isostructural complexes of Co3+ and Rh3+.
  相似文献   

19.
As a result of the accident at the Chernobyl nuclear power plant (NPP) the environment was contaminated with spent nuclear fuel. The 236U isotope was used in this study to monitor the spent uranium from nuclear fallout in soil samples collected in the vicinity of the Chernobyl NPP. Nuclear track radiography was applied for the identification and extraction of hot radioactive particles from soil samples. A rapid and sensitive analytical procedure was developed for uranium isotopic ratio measurement in environmental samples based on double-focusing inductively coupled plasma mass spectrometry (DF-ICP-MS) with a MicroMist nebulizer and a direct injection high-efficiency nebulizer (DIHEN). The performance of the DF-ICP-MS with a quartz DIHEN and plasma shielded torch was studied. Overall detection efficiencies of 4 x 10(-4) and 10(-3) counts per atom were achieved for 238U in DF-ICP-QMS with the MicroMist nebulizer and DIHEN, respectively. The rate of formation of uranium hydride ions UH+/U+ was 1.2 x 10(-4) and 1.4 x 10(-4), respectively. The precision of short-term measurements of uranium isotopic ratios (n = 5) in 1 microg L(-1) NBS U-020 standard solution was 0.11% (238U/235U) and 1.4% (236U/238U) using a MicroMist nebulizer and 0.25% (235U/238U) and 1.9% (236U/P38U) using a DIHEN. The isotopic composition of all investigated Chernobyl soil samples differed from those of natural uranium; i.e. in these samples the 236U/238U ratio ranged from 10(-5) to 10(-3). Results obtained with ICP-MS, alpha- and gamma-spectrometry showed differences in the migration properties of spent uranium, plutonium, and americium. The isotopic ratio of uranium was also measured in hot particles extracted from soil samples.  相似文献   

20.
OUH体系的结构和分析势能函数   总被引:3,自引:0,他引:3  
采用密度泛涵B3LYP方法优化出了OUH分子的各种结构,确定了最稳定构型和离解能,以及它们的谐性力常数,并导出双原子分子UH,UO的Murrell-Sorbie势能函数及其光谱数据。采用多体项展式方法,导出OUH(X^4A')基态分子的分析势能函数,获得OUH(X^4A')体系的势能面,考察了这个势能函数的基本性质,正确地复现出OUH分子的平衡结构特征,结果表明:U+OH,O+UH,H+UO的反应均为无阈能的放热能反应。为进一步探讨OUH体系的反应动力学过程打下了基础。  相似文献   

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