医学生营养与运动知识态度和行为调查

目的：了解医学院在校学生营养与运动知识、态度和行为情况及其影响因素,为针对医学生开展营养及运动健康教育提供参考依据。方法：采用分层整群抽取曲靖医学高等专科学校2012级临床及护理专业在校学生1 050人,通过测量体重、身高,计算BMI值,并同时发放问卷调查了解其营养与运动知识、态度及行为情况。结果：在理想的膳食模式中,每周应进食鱼虾蛋类及牛奶在4次以上的知晓率最低,低于20%;认为一日三餐应规律进食、食物选择应按营养价值选择不足20%;健康饮食行为形成率最低的是不快速进餐。运动知识知晓率不足15%,运动态度良好,90%以上的学生认为应进行体育锻炼,但运动行为较差,能每周坚持3次30min以上有氧运动的学生不足5%。医学生营养与运动知识、态度及行为有明显的性别、民族和生源差异。结论：医学生营养与运动知识、态度及行为情况不容乐观,医学院校应利用自身教学环境的优势加强对学生的健康教育。     

科学营养与运动健身对超重与肥胖的干预

国内外有关肥胖症的相关研究大多都停留在对肥胖症状(单纯性肥胖)产生机制以及肥胖运动治疗的影响因素等研究上。本文综述超重与肥胖的营养干预及运动治疗研究进展,旨在为大众提供一个科学的、合理的、可供参考的、可操作性的营养膳食搭配以及运动减肥负荷量的参考处方。     

不同运动方式改善阿尔茨海默病的机制研究

阿尔茨海默病是一种慢性神经退行性疾病，目前临床尚无特效治疗药物，而运动被认为是一种有效且无害的非医疗干预手段。运动的方式多种多样，不同的运动方式对阿尔茨海默病的改善效果不尽相同。本研究以运动方式的多样性为出发点，综述有氧运动、抗阻运动、高强度间歇运动和多模式运动对阿尔茨海默病的改善作用，分析不同运动方式之间的区别与联系，探究不同运动方式改善阿尔茨海默病的相关机制。虽然不同运动方式改善阿尔茨海默病的机制存在不同，但是均会通过脑源性神经营养因子这一中介缓解疾病进展。本研究可为阿尔茨海默病患者确定最佳运动方式提供理论基础。     

果蔬功能成分与肠道菌群相互作用研究进展

果蔬是日常膳食的重要组成部分,其富含多种具有显著营养健康功效的功能成分,在促进人体健康和预防疾病方面发挥着至关重要的作用。不断有研究证实,果蔬功能成分的多种营养健康功能是通过与肠道菌群的相互作用实现的。从果蔬功能成分对肠道菌群的结构、数量和后续对人体生理功能的影响,以及肠道菌群对果蔬功能成分体内代谢和营养健康作用的影响两大方面,阐述果蔬功能成分与肠道菌群的相互作用研究进展,初步探讨果蔬功能成分-肠道菌群-人体健康的关系,为揭示果蔬营养健康机制,进一步为合理膳食提供重要的参考。     

PP2A在运动抗阿尔茨海默病进程中的机制研究

Tau蛋白过度磷酸化是AD发病的重要原因,促进脑中p-Tau蛋白的脱磷酸化进程是运动抗AD的重要途径。PP2A是重要的蛋白磷酸酶,对p-Tau蛋白的脱磷酸化有重要作用。有关PP2A介导运动抗AD的Tau蛋白磷酸化机制研究尚不多见。现从Tau蛋白与AD研究、PP2A与AD研究、运动与AD研究、PP2A与运动抗AD研究等方面,系统阐述PP2A在介导运动抗AD进程中的蛋白磷酸化机制,为探明运动抗AD的Tau蛋白途径及运动促进健康的蛋白质修饰机制研究提供参考。     

高温、颗粒物污染环境与运动促进健康

特殊环境对人体健康形成了挑战,如何在特殊环境保证人体健康具有较为重要的意义。本文针对高温和颗粒物污染两种特殊环境,对其与运动促进健康的国内外研究动态进行综述。运动和高温是胰岛素抵抗非药物干预治疗的主流,PGC-1α是机体通过运动、高温获得诸多益处的关键调控因子,新型激素Irisin可能是运动和高温改善胰岛素抵抗内在机理的重要环节。颗粒物暴露对运动机体运动能力和呼吸系统有一定的负面影响,但系统运动可以抵抗颗粒物染污负面作用,自由基和炎症途径关系系统运动阻碍颗粒物染污的可能机制。     

DNA甲基化在早期营养程序化中的作用及临床意义研究进展

生命早期营养环境不仅与儿童早期生长发育相关，也影响成年期健康，大量流行病学和动物研究表明早期营养程序化是其重要的生理病理机制。DNA甲基化是营养程序化的重要机制之一，在DNA甲基转移酶的催化作用下，DNA特定碱基共价结合甲基基团，进而调节基因表达。本文总结了DNA甲基化在生命早期过度喂养致关键代谢器官“异常发育规划”继而引起子代远期肥胖、代谢紊乱中的作用，探索通过膳食营养干预调节DNA甲基化水平，以“去编程”的方式早期预防或逆转机体代谢紊乱发生的临床意义。     

从生物化学角度分析运动员的营养需求

运动营养生物化学是结合营养学与生物化学对运动员机体的代谢情况与体能消耗情况进行评估与研究,为其提供科学营养方案的新兴生物科学。本文就目前运动营养生物化学的研究进行了相关内容的分析。     

高强度间歇训练改善认知功能及其机制研究进展

高强度间歇训练(high-intensity interval training,HIIT)已被证明是一种省时、高效的运动策略。与传统的中、低强度有氧运动相比,它可以提供类似甚至更好的健康效益。近年来一些研究表明,HIIT可作为一种有前途的运动康复疗法来改善肥胖、糖尿病、中风、痴呆等疾病引起的认知功能受损。因此,本文综述了HIIT通过促进脑源性神经营养因子分泌、改善氧化应激和增强线粒体适应能力、增加脑乳酸水平及利用率等机制改善认知功能的研究进展,为其预防和/或改善疾病引起的认知功能受损及推广应用提供参考和理论依据。     

天然β-丙氨酸提高运动能力及其机制的研究进展

对补充β-丙氨酸后机体肌肽含量和对不同训练方式运动的影响及其作用机制进行综述,为β 丙氨酸作为营养补充剂和在运动领域中的开发和利用提供科学依据。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.