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61.
N-heterocyclic carbene (NHC) complexes of rhodium(I) (3 and 4) bearing one diether (MeOCH2CH2OCH2CH2-NHC) functionality on N1 and bulky benzyl groups (CH2-C6H2(CH3)3-2,4,6 and CH2-C6(CH3)5) on N3 of (5,6-dimethyl)benzimidazole were synthesized by deprotonation of the corresponding benzimidazolium salt with [Rh(μ-OMe)(1,5-cod)]2 in dichloromethane at ambient temperature. All compounds have been fully characterized by elemental analysis, 1H and 13C NMR spectroscopy. X-ray diffraction studies on single crystals of 3a and 3b confirm the cis square planar geometry. All of the new benzimidazol-2-ylidene rhodium(I) complexes were found to be effective catalysts for the transfer hydrogenation reaction. 相似文献
62.
Immobilization of tyrosinase and alcohol oxidase in conducting copolymers of thiophene functionalized poly(vinyl alcohol) with pyrrole 总被引:1,自引:0,他引:1
Yildiz HB Sahmetlioglu E Boyukbayram AE Toppare L Yagci Y 《International journal of biological macromolecules》2007,41(3):332-337
Immobilization of tyrosinase and alcohol oxidase is achieved in the copolymer of pyrrole with vinyl alcohol with thiophene side groups (PVATh-co-PPy) which is a newly synthesized conducting polymer. PVATh-co-PPy/alcohol oxidase and PVATh-co-PPy/tyrosinase electrodes are constructed by the entrapment of enzyme in conducting copolymer matrix during electrochemical copolymerization. For tyrosinase and alcohol oxidase enzymes, catechol and ethanol are used as the substrates, respectively. Kinetic parameters: maximum reaction rates (V(max)) and Michaelis-Menten constants (K(m)) are obtained. V(max) and K(m) are found as 2.75 micromol/(minelectrode) and 18 mM, respectively, for PVATh-co-PPy/alcohol oxidase electrode and as 0.0091micromol/(minelectrode) and 40 mM, respectively, for PVATh-co-PPy/tyrosinase electrode. Maximum temperature and pH values are investigated and found that both electrodes have a wide working range with respect to both temperature and pH. Operational and storage stabilities show that although they have limited storage stabilities, the enzyme electrodes are useful with respect to operational stabilities. 相似文献
63.
Kabasakal L Sener G Cetinel S Contuk G Gedik N Yeğen BC 《Prostaglandins, leukotrienes, and essential fatty acids》2005,72(6):235-440
There is increasing evidence that oxidative stress has an important role in the development of multiorgan failure after major burn injury. In the present study, we investigated whether the leukotriene receptor blocker montelukast is protective against burn-induced injury of the gut. Under brief ether anaesthesia, shaved dorsum of the rats was exposed to 90 degrees C (burn group) or 25 degrees C (control group) water bath for 10 s. Montelukast (10 mg/kg) or saline was administered intraperitoneally immediately after and at the 12th hour of the burn injury. Rats were decapitated 24 h after burn injury and the skin samples, as well as tissue samples from stomach, ileum and colon, were taken for the determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen contents. Tissues were also examined microscopically. Tumor necrosis factor-alpha (TNF-alpha) and lactate dehydrogenase (LDH) were assayed in serum samples. Severe skin scald injury (30% of total body surface area) caused a significant decrease in GSH level, which was accompanied with significant increases in MDA level, MPO activity and collagen content of tissues. Similarly, serum TNF-alpha and LDH were elevated in the burn group as compared to control group. On the other hand, montelukast treatment reversed all these biochemical indices, as well as histopathological alterations, which were induced by thermal trauma. Findings of the present study suggest that montelukast possesses an anti-inflammatory effect on burn-induced gastrointestinal damage and protects against oxidative injury by a neutrophil-dependent mechanism. 相似文献
64.
A novel methacrylate monomer containing a quinolone moiety was synthesized and homopolymerized in N,N-dimethylformamide (DMF) by using azobisisobutyronitrile (AIBN) as an initiator. The new monomer was copolymerized with poly(ethylene glycol) methyl ether methacrylate (MPEGMA) in DMF using the same initiator. The monomer, homopolymer, and copolymer were characterized by elemental analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), size exclusion chromatography (SEC), FTIR, (13)C NMR, and (1)H NMR. The antibacterial activities of the monomer as well as polymers were investigated against Staphylococcus aureus and Escherichia coli, which are representative of Gram-positive and Gram-negative bacteria, respectively. All compounds showed excellent antibacterial activities against these two types of bacteria. The antibacterial activities were determined using the shaking flask method, where 25 mg/mL concentrations of each compound were tested against 10(5) CFU/mL bacteria solutions. The number of viable bacteria was calculated by using the spread plate method, where 100 microL of the incubated antibacterial agent in bacteria solutions were spread on agar plates and the number of viable bacteria was counted after 24 h of incubation period at 37 degrees C. 相似文献
65.
Plasma soluble intercellular adhesion molecule 1 levels are increased in type 2 diabetic patients with nephropathy 总被引:12,自引:0,他引:12
Güler S Cakir B Demirbas B Yönem A Odabasi E Onde U Aykut O Gürsoy G 《Hormone research》2002,58(2):67-70
BACKGROUND/AIM: Intercellular adhesion molecule 1 (ICAM-1) is a mediator in the recruitment of leukocytes in the glomerular cells. The role of ICAM-1 in diabetic complications is still a matter of debate. This study was performed to investigate the relation of plasma soluble ICAM-1 (sICAM-1) to nephropathy in patients with type 2 diabetes mellitus. METHODS: Ninety-three patients (24 males and 69 females) with type 2 diabetes mellitus were included into the study. Fifty patients had nephropathy, and 43 were free from nephropathy. Fifty healthy subjects (14 males and 36 females) served as the control group (group 1). Twenty-five of the diabetic patients had microalbuminuria (group 2), 25 had macroalbuminuria (group 3), and 43 had neither micro- nor macroalbuminuria (group 4). The plasma sICAM-1 levels were measured in blood samples drawn after fasting. RESULTS: The mean plasma sICAM-1 levels were not different in the 93 diabetic patients as compared with the healthy controls (392.7 +/- 119.5 vs. 350.1 +/- 90.2 ng/ml, p > 0.05). The mean sICAM-1 level was significantly higher in the diabetic patients with nephropathy than in those without nephropathy (430.3 +/- 78.2 vs. 368.2 +/- 122.5 ng/ml, p = 0.03) and in the controls (430.3 +/- 78.2 vs. 350.1 +/- 90.2 ng/ml, p = 0.016). The difference in sICAM-1 levels between groups 2 and 3 was not significant (p > 0.05). The plasma sICAM-1 levels were significantly higher in both groups 2 and 3 than in both groups 1 and 4 (434.5 +/- 129.2 vs. 427.2 +/- 113.7 ng/ml and 368.2 +/- 122.5 vs. 350.1 +/- 90.2 ng/ml, respectively). CONCLUSIONS: The plasma sICAM-1 levels in patients with type 2 diabetes mellitus are not significantly different from those in nondiabetic subjects. High levels of sICAM-1 suggest that sICAM-1 may play a role in the development of nephropathy in patients with type 2 diabetes mellitus. 相似文献
66.
Davis R Jia D Cinar B Sikka SC Moparty K Zhau HE Chung LW Agrawal KC Abdel-Mageed AB 《Biochemical and biophysical research communications》2003,309(4):937-945
Therapeutic resistance remains an unresolved problem in the clinical management of human prostate cancer (PC). Despite initial positive response to androgen ablation therapy (AAT), virtually all PC patients will relapse due to acquisition of hormone refractory disease and selective outgrowth of tumor cells with multidrug resistance phenotype. We here provide the first experimental evidence that restoring a functional androgen receptor (AR) in the androgen-independent prostate cancer PC3 cells enhances their sensitivity to growth arrest and suppresses their colony-forming ability in response to paclitaxel and gamma-irradiation. Furthermore, functional AR increases the susceptibility of these cells to the apoptotic potentials of therapeutic agents, as evidenced by an increase in caspase activity, annexin V binding, and internucleosomal DNA fragmentation, by inducing caspase activation. The abrogation of the cytotoxic effects by 4-hydroxyflutamide suggests a crucial role for AR activation in enhancing the therapeutic sensitivity of these cells in a ligand-independent fashion. Our data thus demonstrate that a functional AR is a prerequisite for effective therapeutic response and that aberrant expression or blockade by AAT may trigger pathways leading to emergence of PC cells with therapeutic resistance phenotype. Since the mainstay of primary therapy for PC has been AAT by pharmaco-therapeutic or surgical means, this study thus provides a new frontier for revising the AAT therapeutic strategy in conjunction with radiation and/or chemotherapeutic agents. 相似文献
67.
68.
Yildiz HB Kiralp S Toppare L Yağci Y 《International journal of biological macromolecules》2005,37(4):174-178
Glucose oxidase was immobilized in conducting copolymers of three different types of poly(methyl methacrylate-co-thienyl methacrylate). Immobilization of enzyme was carried out by the entrapment in conducting polymers during electrochemical polymerization of pyrrole on the copolymer electrodes. Maximum reaction rate, Michaelis-Menten constants, temperature, pH and operational stabilities were determined for immobilized enzyme. The amount of glucose in orange juices of Turkey was investigated by using enzyme electrodes. 相似文献
69.
70.
Sayli BS 《Biological trace element research》1998,66(1-3):409-422
Summary In order to assess the effects of boron and its compounds on human health in a country with the world’s largest deposits,
investigations were carried out on fertility and reproduction in the most highly exposed populations. The 927 probands, 697
male and 230 female, interviewed in the field were selected from six different areas of Turkey, in the provinces of Balikesir,
Eskisehir, and Kutahya, with the highest boron deposits. These people are exposed to boron environmentally or occupationally
or both. The drinking waters of high-boron soils contain 0.7–29 mg B/L compared with 0.05-0.45 mg B/L of low-boron soils.
By the so-called pedigree technique 5,934 marriages were ascertained over three generations from all study areas. Childless
families among 911 probands were 29 in number and 3.17% in frequency with minor variations from one area to the next, and
3.0% averaged over the generations. Infertility rates in a boron-free community near Ankara with 625 families studied over
three generations was 4.48%, and in a larger population of 49,856 families randomly investigated by us throughout the country
was 3.84%. No significant differences were observed in terms of marital status and childbearing between 222 and 399 occupationally
boron-unrelated and boron-related men, respectively. Nor was there any difference with respect to other aspects studied. It
was concluded that, within the limitations of this study, there was no evidence that boron interferes with human fertility
and reproduction. 相似文献