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991.
Chiung-Chih Chang Shih-Jen Tsai Nai-Ching Chen Chi-Wei Huang Shih-Wei Hsu Ya-Ting Chang Mu-En Liu Wen-Neng Chang Wan-Chen Tsai Chen-Chang Lee 《Molecular neurobiology》2018,55(6):4637-4649
The catechol-O-methyltransferase enzyme metabolizes dopamine in the prefrontal axis, and its genetic polymorphism (rs4680; Val158Met) is a known determinant of dopamine signaling. In this study, we investigated the possible structural covariance networks that may be modulated by this functional polymorphism in patients with Alzheimer’s disease. Structural covariance networks were constructed by 3D T1 magnetic resonance imaging. The patients were divided into two groups: Met-carriers (n = 91) and Val-homozygotes (n = 101). Seed-based analysis was performed focusing on triple-network models and six striatal networks. Neurobehavioral scores served as the major outcome factors. The role of seed or peak cluster volumes, or a covariance strength showing Met-carriers > Val-homozygotes were tested for the effect on dopamine. Clinically, the Met-carriers had higher mental manipulation and hallucination scores than the Val-homozygotes. The volume-score correlations suggested the significance of the putaminal seed in the Met-carriers and caudate seed in the Val-homozygotes. Only the dorsal-rostral and dorsal-caudal putamen interconnected peak clusters showed covariance strength interactions (Met-carriers > Val-homozygotes), and the peak clusters also correlated with the neurobehavioral scores. Although the triple-network model is important for a diagnosis of Alzheimer’s disease, our results validated the role of the dorsal-putaminal-anchored network by the catechol-O-methyltransferase Val158Met polymorphism in predicting the severity of cognitive and behavior in subjects with Alzheimer’s disease. 相似文献
992.
Senthil Kumaran Satyanarayanan Yin-Hwa Shih Yu-Chuan Chien Shih-Yi Huang Piotr Gałecki Siegfried Kasper Jane Pei-Chen Chang Kuan-Pin Su 《Molecular neurobiology》2018,55(9):7271-7284
Omega-3 polyunsaturated fatty acids (n-3 or omega-3 PUFAs) and melatonin receptor agonist ramelteon (RMT) both display antidepressant effects, while their cellular effects on anti-oxidative and neuroprotective mechanisms might be different. In this study, we aimed to decipher the individual and synergistic actions of n-3 PUFAs and RMT, as compared with the conventional antidepressant fluoxetine (FLX), in a cellular model of oxidative stress, which might play an important role in the pathophysiology of depression and associated disorders. We investigated the rescue and prevention effects of FLX, RMT, and n-3 PUFAs, e.g., eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), by using cell viability in SH-SY5Y cells under oxidative stress along with measurements of key cellular markers of oxidative stress, inflammatory, and neuroprotection. The results revealed that the RMT and EPA combination significantly increased the cell viability in a dose-dependent manner. RMT showed preventive effects, FLX and DHA possessed rescue effects, while EPA showed both rescue and preventive effects. We observed the dose-dependent activation and translocation of nuclear factor-κB to the nucleus augmented by the expressions of peroxisome proliferator activator receptor-gamma, tyrosine hydroxylase, c-Fos expression, and reactive oxygen species, implying that RMT and EPA combination reversed oxidative and neuroinflammatory pathophysiology and protected the neuronal cells from further damage. The results demonstrated that RMT and EPA synergistically provide effective neuroprotective, anti-oxidative/inflammatory effect against oxidative stress. Our study provides pre-clinical evidence to conduct future clinical trials of using n-3 PUFAs/RMT combination in depressive disorders. 相似文献
993.
Growth of Mycobacterium lepraemurium in Cultures of Mouse Peritoneal Macrophages 总被引:6,自引:2,他引:6 下载免费PDF全文
Successful growth of Mycobacterium lepraemurium was observed in cultures of mouse peritoneal macrophages. The optimal host cell maintenance medium was composed of 40% horse serum, 50% of the chemically defined medium NCTC 109, and 10% of a 1:5 dilution of beef embryo extract, supplemented with both liver extract and ferric nitrate. Multiplication of the bacilli was observed in 1 week and maximal growth in 6 to 7 weeks. All macrophages were filled with tens to hundreds of the organisms in cultures showing maximal growth. Glycerol caused an increase in the normal length of M. lepraemurium, without a corresponding increase in the number of the bacilli. Elongation of M. lepraemurium was observed 3 or 4 days after infection. Rapid and uniform growth of M. lepraemurium was achieved in serially transferred cultures (subcultures). The cumulative increase of the number of intracellular bacilli was 1.4 x 10(20)-fold in 14 transfers over a period of 68 weeks in one series, and 10(17)-fold in 12 transfers over a period of 56 weeks in another series. The generation time of M. lepraemurium was 7 days, a growth rate which approximates the fastest growth of the organisms in vivo. Organisms harvested from cultures at various stages of growth produced murine leprosy in mice, but showed no growth in bacteriological media. The present model offers an opportunity for studies on the host-parasite relationship without the complication of extracellular growth of the parasites. 相似文献
994.
Hangil Chang Naohide Yamashita Hiroshi Matsunaga Kiyoshi Kurokawa 《The Journal of membrane biology》1988,103(3):263-271
Summary We have previously reported hyperpolarizing membrane potential changes in a monkey kidney cell line (JTC-12) which has characteristics resembling proximal tubular cells. These hyperpolarizations could be observed spontaneously or evoked by mechanically touching adjacent cells. In this report, we have shown further evidence that these hyperpolarizations are elicited by an increase in membrane conductance to K+ which is caused by an increase in cytosolic Ca2+ concentration. In addition, we have found another type of hyperpolarization which is evoked by applying flow of extracellular fluid to the cell. Intracellular injection of Ca2+ and Sr2+ evoked hyperpolarizations, while intracellular injection of Mn2+ and Ba2+ did not. Intracellular injection of EGTA suppressed both spontaneous and mechanically evoked hyperpolarizations. In Ca2+-free medium, both spontaneous and flow-evoked hyperpolarizations were not observed, while mechanical stimuli consistently evoked hyperpolarization. In Na+-free medium, the incidence of cells showing the spontaneous or flow-evoked hyperpolarization increased, and the amplitude and the duration of the mechanically evoked hyperpolarization became greater. Quinidine inhibited all types of hyperpolarization. These data suggest that hyperpolarizations in JTC-12 cells are due to an increase in Ca2+-activated K+ conductance. 相似文献
995.
But Paul Pui-Hay Kong Yun-Cheung Li Qian Chang Hong-Ta Chang Kiaw-Lan Wong Khoon-Meng Gray Alexander I. Waterman Peter G. 《植物分类学报:英文版》1988,26(3):205-210
Swingle[14-15] divided Aurantioideac into two tribes, one of which, Clausereae was
further divided into three subtribes, namely, Micromelinae, Clauseninae and Merrilliinae. Mic
romelinae and Merrilliinae each have one genus, whereas Clauseninae has three genera. Morphologically, the Clauseneae is a natural tribe, the five genera are related in a linear sequence,
starting with Micromelum as the most primitive and progressing in sequence to Glycosmis,
Clausena, Murraya and Merrillia. Chemical studies also support this linear relationship, as
revealed by the degree of oxygenation and complexity of the 3-methyl carbazole alkaloids,
from CH3 and C13 in Glycosmis to CHO and C18 in Clausena and COOH and C23 in Murraya[20-21]. Distribution of flavonoids also indicates the progression from Clauseninae to
Merrilliinae[18-19].
Extensive work has been conducted on the chemistry and taxonomy of the genus Murraya [1,5,7-13,16], and the data from these studies clearly indicate the presence of two distinct
groups. Based on a combination of morphological and chemical differences, we agreed with
Tanaka[16-17] in dividing Murraya into two sections, i.e. section Murraya and section Bergera[1].
However, our previous study[1] has not touched on the relationship between the two sections.
Tanaka[16-17] placed section Bergera before section Murraya, and indicated that the former is
close to Micromelum and the latter to Merrillia. Swingle[14-15], on the other hand, put taxa of
section Murraya ahead of those of section Bergera, presumably suggesting that plants of section Murraya are more primitive than those of section Bergera, this arrangement was followed
by Huang[2-3]. The two conflicting viewpoints would have direct bearings on the interpretation of the trends of biogenesis of prenylated indole and carbazole alkaloids, as well as on the
weighing of the relative advancement of the morphological characters within the genus, such
as in the assignment of indices of divergence and in the construction of Wagner Divergence
Diagrams. Without more objective criteria, we find it difficult to select one of the two systems.
In order to determine the relationship between the two sections of Murraya, we decided
to study plants of related genera, with the hope that the chemical data may shed light on the
problem. A plant that attracted our attention is Merrillia caloxylon (Ridley) Swingle. So far,
only eupatorin and a few other flavonoids have been reported from the fruit of this species[4,6].
Although Me. caloxylon belongs to Merrilliinae, a subtribe next to Clauseninae, Tanaka[16-17]
believes that it is close to Murraya section Murraya. Swingle[15], also suggested that this species
might have developed from the same stock that gave rise to Mu. paniculata. If their interpretations were accurate, we would expect that Me. caloxylon would also contain yuehchukene
and 8-prenylated coumarins. The presence of the antiimplantation agent would not only open
up a new source of the compound but also help us judge the relationship between the two sections of Murraya. It is in this context that we studied the chemical composition of Me. caloxylon.
Indeed, root and stem bark of Me. caloxylon were found to contain the antiimplantation indole alkaloid yuehchukene (1), and the 8-prenylated coumarins sibiricin (II) and phebalosin (III), as well as 3-(3-methy1-buta-1,3-diene) indole (IV) and eupatorin (V.) Details
on the chemical profiles are reported in another paper.
Through this exercise, we have confirmed the close relationship between Merrilliinae and
Murraya section Murraya, plants of both taxa contain yuehchukene and 8-prenylated coumarins,
but no carbazole alkaloid. Root and stem bark of Me. caloxylon, like those of plants of section
Murraya, are strawcolored to pale whitish. Its leaves also bear wings along the rachis an in
Mu. alata, and the seeds are also villous. However, Me. caloxylon has long trumpetshaped flowers 55-60 mm long, much larger than those found in other rutaceous plants. Its fruit is ob
long, up to 11 cm long and 8 cm across, bearing a thick and warty pericarp, exuding a very stick
mucilage when cut, and containing numerous seeds (>30). The plant was known to exist in
the Malay Peninsula and north Sumatra[15], but, according to David Jones (per. comm.) of
the University of Malaya, is now only available in cultivation in Malaysia and Singapore, a limitation to any further exploitation as an additional source of yuehchukene.
Besides confirming the close relationship between Merrillia and section Murraya, we may
also conclude that section Bergera is close to Glycosmis and Clausena, since they are known
to contain carbazole alkaloids but no yuehchukene. Accordingly, we find Tanaka’s arrangement more acceptable: plants of section Bergera are more primitive than those of section Murraya, the former is close to Clausena whereas the latter (notably Mu. alata) to Merrillia. The
relationship among the gonera with in Clauseneae may be illustrated as follow: Micromelum→
Glycosmis→Clausena→Murraya sect. Bergera→Murraya sect. Murraya→Marrillia.
Accordingly, we may decide that the following character states are more primitive among plants of Murraya and Merrillia: root and stem bark dark brown, leaf rachis wingless,
flower small, fruit purple-black with few seeds, and seed coat glabrous. In contrast, strawcolored or pale whitish bark, winged leaf rachis, large flower, red or yellow fruit with many
seeds and villous seed coat can be regarded as more advanced characters.
Acknowledgments Partial support was received from the World Health Organization Special Programme on Human Reproduction and the Kevin Hsu Research Fund (to YCK)
and Commonwealth Science Council (to PPHB). The staff of the Singapore Botanic Gardens
and the Forest Research Institute of Malaysia are thanked for their assistance in collecting plantmaterial. 相似文献
996.
997.
998.
999.
Larry M. Palato Shannon Pilcher Alissa Oakes Arleen Lamba Jaris Torres Litza I. Ledesma Monjaraz Crystabel Munoz Edward Njoo Dillon J. Rinauro Kate Alexandra Menefee Angela Tun Betssy L. Jauregui Sarah Shapiro Olivia H. Nossiff Eileen Olivares Kevin Chang Viviane Nguyen Luiza A. Nogaj David A. Moffet 《Journal of peptide science》2019,25(8)
The aggregation of the 37‐amino acid polypeptide human islet amyloid polypeptide (hIAPP), as either insoluble amyloid or as small oligomers, appears to play a direct role in the death of human pancreatic β‐islet cells in type 2 diabetes. hIAPP is considered to be one of the most amyloidogenic proteins known. The quick aggregation of hIAPP leads to the formation of toxic species, such as oligomers and fibers, that damage mammalian cells (both human and rat pancreatic cells). Whether this toxicity is necessary for the progression of type 2 diabetes or merely a side effect of the disease remains unclear. If hIAPP aggregation into toxic amyloid is on‐path for developing type 2 diabetes in humans, islet amyloid polypeptide (IAPP) aggregation would likely need to play a similar role within other organisms known to develop the disease. In this work, we compared the aggregation potential and cellular toxicity of full‐length IAPP from several diabetic and nondiabetic organisms whose aggregation propensities had not yet been determined for full‐length IAPP. 相似文献
1000.
比较广西北部湾石莼(Ulva lactuca L.)、海带(Laminaria japonica)、裙带菜(Undaria pinnatifida Surin-gar)、紫菜(Porphyra)的单糖组成及抗氧化活性的差异,揭示多糖结构与其体外抗氧化活性的关系。利用PMP柱前衍生化HPLC分析海藻多糖的单糖组成,采用羟自由基清除试验、超氧阴离子自由基清除试验及DPPH自由基清除试验指征其体外抗氧化活性,结果表明,4种海藻多糖的单糖组成在主成分空间分布离散,石莼及紫菜主要由葡萄糖组成,海带主要由甘露糖组成,裙带菜则主要由半乳糖组成;其体外抗氧化活性存在显著差异,裙带菜多糖对DPPH的清除能力(半抑制浓度IC50值为0. 56±0. 02 mg/mL)显著高于其他3种海藻多糖;石莼、裙带菜与海带对羟自由基均有较强的清除活性,而紫菜多糖对羟自由基的清除能力较差(IC50值为26. 59±0. 98mg/mL);石莼与裙带菜对超氧阴离子的清除活性较强,显著高于海带与紫菜,其中石莼显著高于裙带菜,IC50值分别为1. 61±0. 17、2. 73±0. 06 mg/mL。相关性分析及冗余分析结果表明,对抗氧化活性影响较为显著的因子为葡萄糖(Glc)、核糖(Rib)、木糖(Xyl)(P <0. 01)。 相似文献