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61.
Xiaojia Ren Diana Boriero Luksana Chaiswing Subbarao Bondada Daret K. St. Clair D. Allan Butterfield 《生物化学与生物物理学报:疾病的分子基础》2019,1865(6):1088-1097
Increasing numbers of cancer patients survive and live longer than five years after therapy, but very often side effects of cancer treatment arise at same time. One of the side effects, chemotherapy-induced cognitive impairment (CICI), also called “chemobrain” or “chemofog” by patients, brings enormous challenges to cancer survivors following successful chemotherapeutic treatment. Decreased abilities of learning, memory, attention, executive function and processing speed in cancer survivors with CICI, are some of the challenges that greatly impair survivors' quality of life. The molecular mechanisms of CICI involve very complicated processes, which have been the subject of investigation over the past decades. Many mechanistic candidates have been studied including disruption of the blood-brain barrier (BBB), DNA damage, telomere shortening, oxidative stress and associated inflammatory response, gene polymorphism of neural repair, altered neurotransmission, and hormone changes. Oxidative stress is considered as a vital mechanism, since over 50% of FDA-approved anti-cancer drugs can generate reactive oxygen species (ROS) or reactive nitrogen species (RNS), which lead to neuronal death. In this review paper, we discuss these important candidate mechanisms, in particular oxidative stress and the cytokine, TNF-alpha and their potential roles in CICI. 相似文献
62.
Alan L. Knight Valentina Mujica Sebastian Larsson Herrera Marco Tasin 《Journal of Applied Entomology》2019,143(8):813-821
Field studies were conducted to evaluate new kairomone blends in combination with pear ester (E,Z)‐2,4‐ethyl decadienoate (PE) and acetic acid (AA) for their attraction of male and female codling moth, Cydia pomonella (L.), in apple, Malus domestica Borkhausen. The addition of decanal to either AA or PE alone significantly increased total and female moth catches. However, the addition of decanal did not improve the attraction of PE + AA. The addition of either the pyranoid (PyrLOX) or furanoid (FurLOX) linalool oxide but not linalool (LOL) increased moth catches with PE but did not increase catches with PE + AA. Similarly, the addition of PyrLOX plus decanal did not improve PE + AA. The addition of (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT) to either AA, PE + AA or PE + AA+decanal did not significantly increase moth catches. However, the addition of PyrLOX to traps with PE + AA and DMNT (4‐component lure) significantly increased moth catches compared with PE + AA alone or any of the ternary blends of these volatiles. Females accounted for 60%–80% of the total catch with this 4‐component lure. The 4‐component blend with PyrLOX was a more attractive lure than similar blends that substituted LOL, or a binary blend of LOL and FurLOX for PyrLOX. The 4‐component blend caught nearly fourfold more total and female moths than the purported attractant N‐butyl sulphide when it was used in combination with PE + AA. These results indicate that significant improvements in monitoring, mating disruption and mass trapping of codling moth are possible. Further studies are needed to assess the new attractive blend's effectiveness in combination with sex pheromone lures and to evaluate whether other host plant volatiles can be added or substitute for DMNT or LOX when used in combination with PE + AA. 相似文献
63.
Amelia P. Guevara Carolyn Vargas Hiromu Sakurai Yasuhiro Fujiwara Keiji Hashimoto Takashi Maoka Mutzuo Kozuka Yoshohiro Ito Harukuni Tokuda Hoyoku Nishino 《Mutation Research - Genetic Toxicology and Environmental Mutagenesis》1999,440(2):1270
In the course of studies on the isolation of bioactive compounds from Philippine plants, the seeds of Moringa oleifera Lam. were examined and from the ethanol extract were isolated the new O-ethyl-4-(α-
-rhamnosyloxy)benzyl carbamate (1) together with seven known compounds, 4(α-
-rhamnosyloxy)-benzyl isothiocyanate (2), niazimicin (3), niazirin (4), β-sitosterol (5), glycerol-1-(9-octadecanoate) (6), 3-O-(6′-O-oleoyl-β-
-glucopyranosyl)-β-sitosterol (7), and β-sitosterol-3-O-β-
-glucopyranoside (8). Four of the isolates (2, 3, 7, and 8), which were obtained in relatively good yields, were tested for their potential antitumor promoting activity using an in vitro assay which tested their inhibitory effects on Epstein–Barr virus-early antigen (EBV-EA) activation in Raji cells induced by the tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA). All the tested compounds showed inhibitory activity against EBV-EA activation, with compounds 2, 3 and 8 having shown very significant activities. Based on the in vitro results, niazimicin (3) was further subjected to in vivo test and found to have potent antitumor promoting activity in the two-stage carcinogenesis in mouse skin using 7,12-dimethylbenz(a)anthracene (DMBA) as initiator and TPA as tumor promoter. From these results, niazimicin (3) is proposed to be a potent chemo-preventive agent in chemical carcinogenesis. 相似文献
64.
Carmen Alicia Peña 《Phytochemistry》1979,18(8):1419-1420
65.
There is growing evidence that preservation of mitochondrial respiratory function during cerebral ischemia-reperfusion predicts the ultimate extent of tissue injury. Because neurons are selectively vulnerable to ischemic injury, many studies have focused on neuronal mitochondrial dysfunction in ischemia. However, positron emission tomography (PET) studies in animals and humans suggest that non-neuronal cells such as astrocytes may also experience mitochondrial metabolic compromise that contributes to ischemic necrosis. Astrocytes carry out a number of functions that are critical to normal nervous system function, including uptake of neurotransmitters, regulation of pH and ion concentrations, and metabolic support of neurons. Mitochondria are important for many of these actions. We have used a cell culture model of stroke, oxygen-glucose deprivation (OGD), to study the response of astrocyte mitochondria to ischemia, and to evaluate how changes in astrocyte mitochondrial function might affect neuronal survival and recovery after ischemia. 相似文献
66.
Contribution of cytosolic cysteine residues to the gating properties of the Kir2.1 inward rectifier 下载免费PDF全文
The topological model proposed for the Kir2.1 inward rectifier predicts that seven of the channel 13 cysteine residues are distributed along the N- and C-terminus regions, with some of the residues comprised within highly conserved domains involved in channel gating. To determine if cytosolic cysteine residues contribute to the gating properties of Kir2.1, each of the N- and C-terminus cysteines was mutated into either a polar (S, D, N), an aliphatic (A,V, L), or an aromatic (W) residue. Our patch-clamp measurements show that with the exception of C76 and C311, the mutation of individual cytosolic cysteine to serine (S) did not significantly affect the single-channel conductance nor the channel open probability. However, mutating C76 to a charged or polar residue resulted either in an absence of channel activity or a decrease in open probability. In turn, the mutations C311S (polar), C311R (charged), and to a lesser degree C311A (aliphatic) led to an increase of the channel mean closed time due to the appearance of long closed time intervals (T(c) >or= 500 ms) and to a reduction of the reactivation by ATP of rundown Kir2.1 channels. These changes could be correlated with a weakening of the interaction between Kir2.1 and PIP(2), with C311R and C311S being more potent at modulating the Kir2.1-PIP(2) interaction than C311A. The present work supports, therefore, molecular models whereby the gating properties of Kir2.1 depend on the presence of nonpolar or neutral residues at positions 76 and 311, with C311 modulating the interaction between Kir2.1 and PIP(2). 相似文献
67.
Fernández-Lorente G Palomo JM Fuentes M Mateo C Guisán JM Fernández-Lafuente R 《Biotechnology and bioengineering》2003,82(2):232-237
It has been found that lipase from Pseudomonas fluorescens (PFL) is able to aggregate into bimolecular structures (MW around 66 kD) even at moderate enzyme concentrations. At very low enzyme concentrations and in the presence of detergents, the same enzyme displayed a unimolecular structure with a molecular weight of 33 kD. Both enzyme structures displayed different functional properties. First, the bimolecular structure was much more stable than the unimolecular species (the bimolecular structure maintained over 80% of initial activity after 72 hours at 45 degrees C, while the unimolecular structure retained only around 30% of initial activity after 4 hours of incubation under the same experimental conditions); and the bimolecular form presented a higher optimal T. Second, the unimolecular form showed a much lower K(M) for ethyl butyrate than the bimolecular form. Third, the interfacial activation in biphasic substrate-aqueous milieu was higher for the bimolecular form. Fourth, the unimolecular structure was less active but much more enantioselective than the unimolecular species in the model reaction used. It is proposed that the bimolecular aggregates of PFL might be formed by two open lipase molecules (mutual interfacial activation), in intimate contact, and that the bimolecular form represents an example of "pseudo-quaternary" structure. 相似文献
68.
Sashiwa H Kawasaki N Nakayama A Muraki E Yajima H Yamamori N Ichinose Y Sunamoto J Aiba S 《Carbohydrate research》2003,338(6):557-561
The Michael type reaction of chitosan with ethyl acrylate has been investigated. Although this reaction was quite slow in the case of chitosan, the reiteration of the reaction was an effective means for increasing the degree of substitution (DS) of ethyl ester. The N-carboxyethylchitosan ethyl ester as an intermediate was successfully substituted with various hydrophilic amines, although the simultaneous hydrolysis of the ester to carboxylic acid also occurred. Water-soluble chitosan derivatives were obtained by substitution with hydroxyalkylamines and diamines. 相似文献
69.
Screening and characterization of astaxanthin-hyperproducing mutants of Haematococcus pluvialis 总被引:1,自引:0,他引:1
Haematococcus pluvialis was mutated by UV or ethyl methanesulphonate. Mutants resistant to nicotine, diphenylamine, fluridone or norflurazon were then selected. Several nicotine-resistant mutants showed increased (1.9% to 2.5% vs. 1.2% w/w) astaxanthin production. Mutants maintained high astaxanthin production over 4 months of repeated culture. 相似文献
70.
A Pseudomonas sp. was isolated with enantioselective epoxide hydrolase activity to ethyl 3-phenylglycidate. Cells grown on sucrose and suspended in 10% (v/v) dimethyl formamide as co-solvent produced (2R,3S) ethyl 3-phenylglycidate with 95% ee and 26% yield in 12 h from 0.2% (w/v) of the racemate. 相似文献