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91.
Gas chromatography-mass spectrometry has been applied to the analysis of plasma linoleic acid and one of its oxidation products, 4-hydroxy-2-nonenal (HNE), in adult patients with the acute respiratory distress syndrome (ARDS). Peak areas of total ion chromatograms showed there to be negative correlations between loss of linoleic acid and formation of HNE (measured by selective ion monitoring) in 7 out 10 patients studied. When HNE was quantitated by selective ion monitoring, with reference to a pure standard of HNE and an internal standard of nonanoic acid, ARDS patients showed significantly increased levels of HNE (0.412 ± 0.023 nmol/ml) compared with normal healthy controls (0.205 ± 0.018 nmol/ml). 相似文献
92.
T. Mastrocola I. H. Lambert B. Kramhøft M. Rugolo E. K. Hoffmann 《The Journal of membrane biology》1993,136(1):55-62
Trypsinized human skin fibroblasts in suspension perform regulatory volume decrease (RVD) after cell swelling in hypotonic medium. During RVD, 36Cl– efflux is dramatically increased and the cell membrane is depolarized, indicating the activation of Cl– channels. This activation of Cl– channels depends on extracellular as well as on intracellular Ca2+. The swelling-induced Cl– efflux and the RVD response are inhibited by the 5-lipoxygenase inhibitor ETH 615-139. Finally, following hypotonic treatment, cellular pH decreases. The pH decrease does not involve the Cl–/HCO
3
–
exchange because it is independent of the external Cl– concentration.T. Mastrocola was recipient of a scientific fellowship from the Italian Consiglio Nazionale delle Ricerche (C.N.R.). This work was supported by Progetto Finalizzato Ingegneria Genetica, C.N.R., Roma, and by the Danish Natural Research Council. 相似文献
93.
Abstract: The present study reports the ion dependency of 2β-carbomethoxy-3β-(4-fluorophenyl)[3 H]tropane ([3 H]- CFT) binding to the dopamine transporter in the rat striaturn. The results indicate that [3 H]CFT binding to synaptosomal P2 membranes requires low concentrations of Na+ (peak binding between 20 and 50 m M Na+ ), is stimulated by phosphate anion or l- , but is unaffected or only slightly affected by F- , Cl- , Br- , NO3 - , or SO4 2- , Concentrations of Na+ of >50 m M become inhibitory except in the presence of l- , which shifts peak binding levels toward higher Na+ concentrations and also elevates the peak binding level. K+ strongly decreased [3 H]CFT binding with a shallow inhibition curve, and Na+ could not overcome this effect. Saturation analysis of [3 H]CFT binding revealed a single binding site changing its affinity for CFT depending on the concentration of sodium phosphate buffer (6, 10, 30, 50, 130, or 200 m M ; 1 mM plus 49 mM NaCIversus 10 m M plus 40 m M NaCI; or 1 mM plus 129 m M Nal versus 10 m M plus 120 m M Nal). No differences were observed in the density of CFT binding sites between any of the conditions examined. 相似文献
94.
95.
The protective effect of arbutin against potassium bromate-induced oxidative damage in the rat brain
H. Turan Akkoyun Ahmet Uyar Mahire Bayramoglu Akkoyun Aydın Şükrü Bengü Şule Melek Fatma Karagözoğlu Sevinç Aydın Suat Ekin Sinem Aslan Erdem 《Journal of biochemical and molecular toxicology》2023,37(2):e23248
This study aimed to investigate the protective effects of arbutin (ARB) against brain injury induced in rats with potassium bromate (KBrO3). The rats were divided into four groups as Group 1: Control (0.9% NaCl ml/kg/day p.), Group 2: KBrO3 (100 mg/kg (gavage), Group 3: ARB (50 mg/kg/day p.), and Group 4: KBrO3 + ARB (100 mg/kg (gavage) + 50 mg/kg/day p.). At the end of the fifth day of the study, the rats in all groups were killed, and their brain tissues were collected. In the collected brain tissues, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) levels were measured, and routine histopathological examinations were made. The MDA levels in the group that was exposed to KBrO3 were significantly higher than those in the control group (p ˂ 0.001). In comparison to the KBrO3 group, the MDA levels in the KBrO3 + ARB group were significantly lower (p ˂ 0.001). It was observed that SOD and CAT enzyme activity levels were significantly lower in the KBrO3 group compared to the control group (p ˂ 0.001), while these levels were significantly higher in the KBrO3 + ARB group than in the KBrO3 group (p ˂ 0.001). Additionally, the group that was subjected to KBrO3 toxicity, as well as ARB administration, had much lower levels of histopathologic signs than the group that was subjected to KBrO3 toxicity only. Consequently, it was found that KBrO3 exposure led to injury in the brain tissues of the rats, and using ARB was effective in preventing this injury. 相似文献
96.
N-nitro-l-arginine (NG-nitro-l-arginine) is a potent nitric oxide synthase inhibitor which crosses the blood brain barrier and does not undergo extensive metabolism in vivo. In this study, effect of chronic pretreatment of N-nitro-l-arginine (75 mg/kg, i.p., twice daily for 7 days) on the harmaline- (100 mg/kg, s.c.), picrotoxin- (4 mg/kg, s.c.), pentylenetetrazole- (50 mg/kg, i.p.), andl-glutamic acid- (400 g/10 l/mouse, i.c.v.) induced increase in cerebellar cGMP was assessed. All the four drugs produced significant increase in cerebellar cGMP in vehicle pretreated control animals. Cerebellar cGMP increase induced by harmaline, picrotoxin, andl-glutamic acid was attentuated in N-nitro-l-arginine pretreated animals. These results indicate that in vivo cerebellar cGMP levels are increased by the prototype excitatory amino acid receptor agonist,l-glutamic acid and also by the drugs which augment the excitatory amino acid transmission. Furthermore, parenteral chronic administration of N-nitro-l-arginine blocks NO synthase in the brain and hence cerebellar cGMP response in chronic N-nitro-l-arginine treated animals could be used as a tool to assess the physiological functions of nitric oxide in vivo.Part of this work was presented at the Experimental Biology 93 FASEB Meeting at New Orleans, March 1993. 相似文献
97.
Single-step synthesis of novel 4-hydrazinothiazole derivatives 6a–e was achieved under mild conditions using the sequential four-components method involving isothiocyanate, aminoguanidine, carbonyl adduct, and α-haloketone derivatives. Deprotection of these hydrazinothiazoles was influenced by acylation, providing a novel group of diacylated molecular structures with a broader scope for the design of thiazolyl-containing drugs 7a and 7b . FTIR, 1H/13C NMR, LC–MS spectroscopy, and CHN elemental analyses were used to study the compound chemical structures. Using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on human periodontal ligament fibroblast (HPDLF) cells, the 4-hydrazinothiazole derivatives were screened for cytotoxicity in an in vitro cytotoxicity investigation. The 4-hydrazinothiazole compound 6b bearing an isopropylidene-hydrazino group demonstrated strongly potent cytotoxicity against CAKI1 (IC50 = 1.65 ± 0.24 μM) and A498 (IC50 of 0.85 ± 0.24 μM). Furthermore, the chloroacetyl-containing thiazole compound 7a displayed efficient inhibition of growth against the test cell lines CAKI1 and A498 at low micromolar concentrations, IC50 0.78 and 0.74 μM, respectively. 相似文献
98.
Biodegradation of 4-chlorobiphenyl by Micrococcus species 总被引:1,自引:0,他引:1
A Micrococcus sp., isolated by enrichment culture, grew on 4-chlorobiphenyl at 2 g/l as sole carbon source and produced 4-chlorobenzoic acid in the culture medium as a dead-end metabolite. The organism degraded 4-chlorobiphenyl by 2,3-dihydroxylation followed by meta-ring cleavage to yield 4-chlorobenzoate and carbon fragments for cell growth. 相似文献
99.
Robin T. Clowes Wayne Boucher Colin H. Hardman Peter J. Domaille Ernest D. Laue 《Journal of biomolecular NMR》1993,3(3):349-354
Summary We recently proposed a novel four-dimensional (4D) NMR strategy for the assignment of backbone nuclei in spectra of 13C/15N-labelled proteins (Boucher et al. (1992) J. Am. Chem. Soc., 114, 2262–2264 and J. Biomol. NMR, 2, 631–637). In this paper we extend this approach with a new constant time 4D HCC(CO)NNH experiment that also correlates the chemical shifts of the aliphatic sidechain (1H and 13C) and backbone (1H, 13C and 15N) nuclei. It separates the sidechain resonances, which may heavily overlap in spectra of proteins with large numbers of similar residues, according to the backbone nitrogen and amide proton chemical shifts. When used in conjunction with a 4D HCANNH or HNCAHA experiment it allows, in principle, complete assignment of aliphatic sidechain and backbone resonances with just two 4D NMR experiments. 相似文献
100.
Summary In order to understand the nature of interspecific barriers in Populus, we have explored pollen/pistil interactions in intra- and interspecific crosses Populus nigra x P. nigra and P. nigra x P. alba. The kinetics of pollen-tube growth demonstrated that P. nigra and P. alba pollen tubes have distinct behavioral patterns inside P. nigra pistils. P. alba pollen tubes exhibit an unique S-shaped growth curve and an arrested growth site near the sylodium. P. nigra pollen tubes exhibit two growth phases, in the stigmatic tissues and in the ovarian cavity respectively. P. nigra and P. alba curves diverge 5 h after controlled pollination and could be related to a change in the physiology of the P. nigra pollen tube, which shifts from an autotrophic to a heterotrophic type of nutrition. Protein analysis of pollinated stigmatic extracts (0,6 and 20 h after pollination) revealed qualitative and quantitative differences that are related to the presence of either P. nigra or P. alba pollen tubes inside the stigmatic tissues. Increasing numbers of protein bands were detectable from 0 to 20 h after pollination only in intraspecific cross. Glycoproteins were detected, and the differences observed were dependent of the cross. -Galactosidase activity was found in pollinated stigmas, but an increase in its activity (one isozyme of pHi 4.2) between 6 h and 20 h after pollination was detected only in the intraspecific cross. This enzyme could play a role in heterotrophic pollen-tube nitrition, and its activity could be the final result of a series of interactions started by the initial pollen-stigma dialog. 相似文献