药用植物刺山柑愈伤组织诱导及细胞生长代谢特征研究

本文研究了不同外植体及激素对刺山柑愈伤组织诱导的影响,不同激素配比对愈伤组织增殖培养以及悬浮细胞的生长与代谢特征。结果表明:以刺山柑叶片作为诱导愈伤组织的材料,效果较佳;愈伤组织诱导和继代的适宜培养条件是分别是MS 0.5mg/L 2,4-D 1.0mg/L6-BA和MS 1.0mg/L2,4-D 1.5mg/L6-BA。刺山柑悬浮培养细胞的生长周期为30天左右,细胞生长曲线呈"S"形,生物量增长2.8倍左右;细胞生长周期内,碳源消耗规律表现为蔗糖和可溶性总糖的浓度持续降低,而还原糖则表现为先升高后降低;过氧化物酶活测定显示酶活水平与蔗糖浓度的高低呈一定程度的正相关。     

药用植物刺山柑愈伤组织诱导及细胞生长代谢特征研究

本文研究了不同外植体及激素对刺山柑愈伤组织诱导的影响,不同激素配比对愈伤组织增殖培养以及悬浮细胞的生长与代谢特征.结果表明:以刺山柑叶片作为诱导愈伤组织的材料,效果较佳;愈伤组织诱导和继代的适宜培养条件是分别是MS+0.5 mg/L 2,4-D+1.0mg/L6-BA和MS+1.0mg/L2,4-D+1.5mg/L6-BA.刺山柑悬浮培养细胞的生长周期为30天左右,细胞生长曲线呈"S"形,生物量增长2.8倍左右;细胞生长周期内,碳源消耗规律表现为蔗糖和可溶性总糖的浓度持续降低,而还原糖则表现为先升高后降低;过氧化物酶活测定显示酶活水平与蔗糖浓度的高低呈一定程度的正相关.     

NaCl胁迫对唐古特白刺愈伤组织的生理效应

以唐古特白刺(Nitraria tangutorum Bobr.)愈伤组织为材料,研究低(75 mmol/L)、中(150 mmol/L)、高(300 mmol/L)浓度NaCl处理下其膜脂过氧化、抗氧化酶活性及渗透性调节物含量的变化,试图从细胞水平揭示唐古特白刺适应盐环境的生理机制。结果显示:(1)唐古特白刺愈伤组织中MDA含量在低浓度NaCl处理下与对照无显著性差异,而在中高浓度下显著升高。(2)白刺愈伤组织超氧化物歧化酶(SOD)活性在各浓度NaCl胁迫下均比对照显著升高,且此效应无浓度依赖性;其过氧化氢酶(CAT)活性随胁迫浓度的增加呈先升高后降低的变化趋势,在中低浓度下比对照显著增加,高浓度下显著降低为对照的64%;其过氧化物酶(POD)活性在低浓度下无显著性变化,在中高浓度显著下降为对照的55%和29%。(3)随NaCl胁迫浓度的增加,白刺愈伤组织中脯氨酸、可溶性糖和可溶性蛋白含量均呈先升高后降低的变化趋势,且除高浓度下可溶性蛋白含量约降为对照的87%外,其余NaCl胁迫处理的3种渗透调节物含量均高于对照。研究发现,白刺愈伤组织在低浓度的盐胁迫下具有较强的抗氧化酶活性和渗透性调节作用,因而表现出较强的抗氧化作用,但高浓度NaCl胁迫对白刺愈伤组织造成了显著的氧化损害。     

黑暗和光照对长春花培养细胞生长和生理生化特性的影响

以长春花(Catharanthus roseus(L.)G．Don)幼嫩叶片为外植体,在。MS NAA 0．5mg／L, 2,4一D0．5mg／L 6 BA 2．0mg／L培养基上诱导形成愈伤组织,愈伤组织置于不同条件下培养。结果表明,黑暗和光照下,培养细胞的生长周期为27d;过氧化物酶(POD)活性和超氧化物歧化酶(SOD)活性均出现2个峰值。对长春花总生物碱含量和总产量亦做了研究,结果发现最佳的收获时期为第27d。     

丹参愈伤组织的诱导及增殖效应

以丹参(Salvia miltiorrhiza bunge)的幼叶、茎、叶柄为外植体,接种于附加2,4—D、MM、Kr、Zr、6—BA及其组合的hIs固体培养基上,结果发现单独使用四种植物生长调节物质在一定浓度范围均有愈伤组织产生;最佳组合的诱导培养基为MS 2,4—D0．5mg/L 6—BA1．0mg/L。进一步研究发现,在黑暗和光照培养条件下,愈伤组织增殖呈“S”型,且生长周期均为30天。     

诺丽茎段愈伤组织诱导优化及细胞悬浮系的建立

为获取诺丽茎段中的次生代谢物并为建立遗传转化体系奠定基础,以诺丽茎段(无腋芽)为外植体诱导愈伤组织,并建立细胞悬浮系,对影响愈伤组织的诱导及细胞悬浮系的因子进行了研究。结果表明:愈伤组织诱导的最优培养基是MS+1.0mg/L6-BA+0.1mg/L2,4-D;悬浮培养的最佳培养基为MS+1.0mg/L6-BA+0.1mg/L2,4-D+3%蔗糖,pH为5.85,当初始接种量为37.5g/L、摇床转速为110r/min且(25±2)℃暗培养时,悬浮细胞生长良好,生长速率最大;诺丽茎段悬浮细胞生长曲线呈"S"型,最适继代周期为12–20 d;培养过程中,培养基的pH呈先下降后缓慢升高的变化趋势,诺丽茎段愈伤组织悬浮细胞培养的最适pH在4.5–5.0之间。文中成功建立了以诺丽茎段为外植体的稳定的细胞悬浮系。     

水翁悬浮细胞系的建立及其悬浮培养的生长特性

建立了水翁悬浮细胞系,并对其悬浮培养的生长特性作了初步探讨。以水翁新生芽尖作为外植体,接种于添加有不同浓度和配比的生长调节物质及各种附加物的MS固体培养基中,诱导培养产生初代愈伤组织;挑选Ⅰ和Ⅱ型的愈伤组织进行继代培养改良,考察愈伤组织的生长状况和统计生长量来决定最佳继代培养基的配方和得到适合悬浮培养的愈伤组织;将以上得到的愈伤组织转接于最佳继代液体培养基中,于24±1℃,120r/min条件下振荡培养,筛选分散度好、较均匀、生长快、色浅透明的细胞作为种子传代,数次传代后得到性能良好的悬浮细胞系;以细胞生长量(鲜重)为指标,绘制了水翁悬浮细胞的生长曲线。研究表明:2.0mg/L的2,4-D的诱导率最高(92%,初代愈伤组织为Ⅰ型),Ⅱ型愈伤组织的最高诱导率为75%;最佳的继代培养基配方为MS 0.5mg/L 2,4-D 0.5mg/L 6-BA 1.0mg/L IAA 0.5mg/L IBA 0.5mg/L NAA 0.1mg/L KT 700mg/L LH,形成Ⅱ型愈伤组织的生长量可达3.28g/瓶(鲜重);液体继代培养3代后,可得到性能良好的悬浮细胞系;水翁悬浮细胞的生长曲线表明,最佳接种期为培养后的16~18d。     

EMS诱变和NaCl胁迫的正交实验及耐盐纤维亚麻种质的筛选

旨为经愈伤组织诱导再生的耐盐性纤维亚麻植株奠定基础。以3种纤维亚麻无菌苗的下胚轴段为材,经EMS诱变和盐胁迫的正交实验,再经诱芽和愈伤组织培养,研究其理化特性。结果显示,‘范妮’、‘天鑫3号’和‘双亚5号’下胚轴段不定芽培养的最适处理组合均为0.025%EMS处理2 h(或4 h),之后用100或150 mmol/L Na Cl处理12 h;总产芽率由高到低分别为‘范妮’、‘天鑫3号’和‘双亚5号’下胚轴段;对3种亚麻不定芽生长影响的顺序为:Na Cl浓度EMS浓度EMS处理时间;3种亚麻下胚轴段不定芽诱导的适宜培养基为MS+0.000 2 mg/L TDZ+0.02 mg/L KT+0.005 mg/L NAA+0.3%蔗糖+0.1 g/L肌醇+3.3 g/L植物凝胶。经0.025%EMS处理4 h+150 mmol/L Na Cl处理12 h后生长的愈伤组织,经过2次交替筛选后,其理化指标表明,与对照组的相比,3种亚麻处理组愈伤组织脯氨酸、可溶性糖、可溶性蛋白含量、SOD和POD活性均显著提高(P0.05)。经过0.025%EMS处理4 h+150 mmol/L Na Cl处理12 h后生长的愈伤组织具有一定的耐盐性。     

银杏愈伤组织生长、褐化与黄酮积累研究

旨在建立稳定的银杏愈伤组织继代体系,筛选细胞活性强且黄酮产量高的细胞培养条件,为工业化生产提供一定参考。以MS培养基为基本培养基,在40 d的继代周期内设计正交实验研究外植体月份、外源激素与抗褐化剂交互作用下的银杏愈伤组织生长、褐化与黄酮积累,并对比了4、5、6月中旬银杏叶片黄酮含量。结果表明,银杏愈伤组织继代中的最佳生长组合为:4月叶片诱导的愈伤组织+3.0 mg/L NAA+0.5 mg/L KT+5 mg/L VC;最佳抗褐化组合为:4月叶片诱导的愈伤组织+1.0 mg/L NAA+1.0mg/L KT+10 mg/L VC;银杏叶黄酮含量从4-6月呈上升趋势,且不同月份叶片诱导的愈伤组织黄酮含量与之呈正相关,以6月叶片诱导的愈伤组织+2.0 mg/L NAA+1.0 mg/L KT+5 mg/L VC为最佳黄酮积累条件;结合愈伤组织干重,总黄酮实际产量最高组合为:5月叶片诱导的愈伤组织+2.0 mg/L NAA+0.5 mg/L KT+5 mg/L VC。银杏愈伤组织的适宜继代周期为24-32 d,生长量较大且褐化率低。     

TDZ对喜树愈伤组织生长及色素积累的影响

目的:研究苯基噻二唑基脲(Thidiazuron,TDZ)对喜树愈伤组织生长及叶绿素、花青素积累的影响。方法:采用TDZ单独应用及合并植物激素对喜树愈伤组织进行了继代培养。结果:单独应用TDZ时1mg/L为组织生长最适浓度。1mg/L TDZ+0.5mg/L NAA可显著促进愈伤组织的生长及叶绿素的积累,1mg/L TDZ+0.5mg/L 2,4-D培养条件下花青素含量高于单独应用TDZ培养。结论:TDZ在喜树愈伤组织培养中可替代植物激素并对细胞植物色素积累有明显影响。     

Structure and function of S-adenosylhomocysteine hydrolase

In mammals, S-adenosylhomocysteine hydrolase (AdoHcyase) is the only known enzyme to catalyze the breakdown of S-adenosylhomocysteine (AdoHcy) to homocysteine and adenosine. AdoHcy is the product of all adenosylmethionine (AdoMet)-dependent biological transmethylations. These reactions have a wide range of products, and are common in all facets of biometabolism. As a product inhibitor, elevated levels of AdoHcy suppress AdoMet-dependent transmethylations. Thus, AdoHcyase is a regulator of biological transmethylation in general. The three-dimensional structure of AdoHcyase complexed with reduced nicotinamide adenine dinucleotide phosphate (NADH) and the inhibitor (1′R, 2′S, 3′R)-9-(2′,3′-dihyroxycyclopenten-1-yl)adenine (DHCeA) was solved by a combination of the crystallographic direct methods program, SnB, to determine the selenium atom substructure and by treating the multiwavelength anomalous diffraction data as a special case of multiple isomorphous replacement. The enzyme architecture resembles that observed for NAD-dependent dehydrogenases, with the catalytic domain and the cofactor binding domain each containing a modified Rossmann fold. The two domains form a deep active site cleft containing the cofactor and bound inhibitor molecule. A comparison of the inhibitor complex of the human enzyme and the structure of the rat enzyme, solved without inhibitor, suggests that a 17° rigid body movement of the catalytic domain occurs upon inhibitor/substrate binding.     

Land,livestock, and livelihoods: Changing dynamics of gender,caste, and ethnicity in a Nepalese Village

Over the past 10 years, Ghusel VDC, Lalitpur District has moved from primarily subsistence agriculture into the wider cash economy aided by the Small Farmers' Development Program (SFDP), which provides credit to farmers mainly for the purchase of buffalo for milk production, and by the National Dairy Corporation, which supports local dairy cooperatives. Analysis reveals that buffalo-keeping and milk sales are increasing the well-being of many households, while at the same time creating new inequalities in gender roles and responsibilities, greater inequities between Brahmin and Tamang residents in Ghusel, and placing pressures on the ecosystem for increased supplies of fodder and fuelwood. Evidence suggests that there is critical, need for attention to the social, and particularly gender-based, implications of maintaining livestock for milk sales and to the ecological underpinnings of this livelihood system.     

Tuning of electronic properties of one-dimensional cyano-bridged Cu-Ni, Cu-Pd, and Cu-Pt bimetallic assemblies by stereochemistry of ligands

Preparations, XPS and electronic spectroscopy, and magnetism of seven new one-dimensional cyano-bridged coordination polymers, chiral [Cu(RR-chxn)₂][Pd(CN)₄] · 2H₂O (1), [Cu(trans-chxn)₂][M(CN)₄] · 2H₂O (2, 4, and 6 for M = Pd, Ni, and Pt), and [Cu(cis-chxn)₂][M(CN)₄] · 2H₂O (3, 5, and 7 for M = Pd, Ni, and Pt) (RR-chxn = cyclohexane-(1R,2R)-diamine, trans-chxn = racemic trans-cyclohexane-(1,2)-diamine, and cis-chxn = racemic cis-cyclohexane-(1,2)-diamine) have been reported in view of tuning of their electronic properties by stereochemistry of chxn ligands and metal-substitution. Comparison of Cu 2p_1/2 and 2p_3/2 peaks of XPS and broad d-d bands around 18 000 cm⁻¹ of electronic spectra are described systematically for 1-7. Variable-temperature magnetic measurement shows that complexes 1-7 indicate weak antiferromagnetic interactions via cyano-bridges. Because of semi-coordination coupled with pseudo Jahn-Teller elongation and electrostatic interaction for 1, the axial Cu-N coordination bond distances of 2.330(7) and 3.092(8) Å are considerably longer than those of equatorial ones in the range from 2.016(6) to 2.030(6) Å. The former bond distances of 1 are intermediate values among the related Ni (2.324(6) and 3.120(8) Å) and Pt (2.34(1) and 3.09(1) Å) complexes.     

Influence of Fluoride on Rat Kidney Antioxidant System: Effects of Methionine and Vitamin E

The aim of the study has been to determine and compare the influence upon the kidney antioxidative system, exercised by administration of vitamin E, and vitamin E in combination with methionine, under conditions of oxidative stress induced by sodium fluoride. The experiment was carried out on Wistar FL rats (adult males) that, for 35 days, were administered water, NaF, NaF with vitamin E, or vitamin E with methionine (doses: 10 mg NaF/kg of body mass/24 h, 3 mg vitamin E per 10 μl per rat for 24 h, 2 mg methionine per rat for 24 h). The influence of administered sodium fluoride and antioxidants upon the antioxidative system in kidney was examined by analyzing the concentration of malondialdehyde (MDA) and the activity of the most important antioxidative enzymes (SOD, total and both its isoenzymes, GPX, GST, GR, and CAT). The studies carried out confirmed the disadvantageous effect of the administered dose of NaF upon the antixodiative system in rats (increase in the concentration MDA, decrease activity of all antioxidative enzymes). The administration of vitamin E increased the activity of studied enzymes with the exception of glutathione reductase GR; it also reduced the procesess of lipid peroxidation. It has been found that combined doses of vitamin E and methionine were most effective in inhibiting lipid peroxidation processes. The results confirmed the antioxidative properties of methionine.     

Reorientation of Microfibrils and Microtubules at the Outer Epidermal Wall of Maize Coleoptiles During Auxin-Mediated Growth

Auxin-mediated elongation growth of isolated subapical coleoptile segments of maize (Zea mays L.) is controlled by the extensibility of the outer cell wall of the outer epidermis (Kutschera et al., 1987). Here we investigate the hypothesis that auxin controls the extensibility of this wall by changing the orientation of newly deposited microfibrils through a corresponding change in the orientation of cortical microtubules. On the basis of electron micrographs it is shown that cessation of growth after removal of the endogenous source of auxin is correlated with a relative increase of longitudinally orientated microfibrils and microtubules at the inner wall surface. Conversely, reinduction of growth by exogenous auxin is correlated with a relative increase of transversely orientated microfibrils and microtubules at the inner wall surface. These changes can be detected 30–60 min after the removal and addition of auxin, respectively. The functional significance of directional changes of newly desposited wall microfibrils for the control of elongation growth is discussed.     

邻苯二甲酸二丁酯对翡翠贻贝抗氧化酶及脂质过氧化水平的影响

实验室条件下,研究了不同浓度邻苯二甲酸二丁酯(DBP)长期胁迫(15 d)对翡翠贻贝内脏团和外套膜抗氧化酶(超氧化物歧化酶SOD、过氧化氢酶CAT)及脂质过氧化(LPO)水平(以MDA含量表示)的影响,以及受胁迫翡翠贻贝在清洁海水中恢复阶段上述生化指标的变化特征.结果表明:胁迫阶段,0.5和2.5 mg.L-1DBP下翡翠贻贝内脏团SOD活性表现为先抑制后逐渐恢复,12.5和62.5 mg.L-1下则持续受到显著抑制;不同浓度组CAT活性均明显被抑制.LPO水平明显升高.外套膜中,2.5 mg.L-1下SOD活性受到持续诱导,其他浓度组则先被抑制,后随曝露时间延长逐渐被诱导;各浓度组CAT的变化波动较大,没有明显规律;而LPO水平明显升高.净化恢复阶段,12.5和62.5 mg.L-1DBP胁迫下的内脏团SOD和CAT活性恢复较慢,其LPO水平随时间延长逐渐恢复至对照组水平;外套膜中SOD活性呈持续升高趋势,CAT活性和LPO水平则随时间延长恢复到对照组水平.     

眶额叶微量注射谷氨酸和γ-氨基丁酸对胃运动的影响及其机制探讨

目的:研究眶额叶(OFC)的谷氨酸(Glu)和γ-氨基丁酸(GABA)含量变化对胃运动的影响及其调节神经机制。方法:实验采用了大鼠眶额叶微量注射给药,结合核团损毁的方法,以记录胃内压,统计胃收缩幅度作为胃运动变化的指标。结果:①OFC注射Glu可显著降低胃收缩幅度,损毁杏仁核后可反转该效应,胃收缩幅度显著增强;损毁蓝斑核后,Glu的作用无显著性变化。②OFC注射GABA可显著增强胃的收缩幅度,损毁蓝斑核后消除该效应;损毁杏仁核后,胃收缩幅度进一步增强。结论:外源性增加OFC区Glu含量导致的抑胃效应可能是通过增强了杏仁核的经常性抑胃作用而引起的;而增加OFC区GABA的含量引起的胃运动增强与蓝斑核密切相关。     

In vitro studies of the rabbit immune system. IV. Differential mitogen responses of isolated T and B cells.

The mitogenic responses of separated rabbit lymphocyte populations functionally analogous to mouse T and B cells have been tested in vitro. Purified T cells were prepared by passage over nylon wool (NW) and purified B cells prepared by treatment with antithymocyte serum and complement (ATS + C). ATS + C kills 70% of peripheral blood lymphocytes (PBL's) and 50% of the spleen cells while passage over NW yields 40% of the applied PBL's and 5–23% of the applied spleen cells. NW-purified T cells from the spleen or PBL's respond fully to concanavalin A (Con A) but have a reduced response to phytohemaglutinin (PHA) and little or no response to goat anti-rabbit immunoglobulin (anti-Ig). PBL's that survive ATS + C (B cells) are stimulated by anti-Ig but not by Con A or PHA. B cells purified from spleen do not respond to Con A or PHA but will respond to anti-Ig under appropriate conditions. A full spleen B-cell response to anti-Ig required removal of Ig produced by the cultures that blocked anti-Ig stimulation. It is concluded that, for rabbit lymphocytes, Con A and PHA are primarily T-cell mitogens and that anti-Ig is primarily a B-cell mitogen. However, the mitogen response of unfractionated PBL or spleen cell populations indicates an overlap in reactivity. This could be due to cells sharing T and B properties, alteration of cell populations by the fractionation procedures used, or recruitment of one population in the presence of a mitogenic response of the other population.     

X-ray induction of dominant lethals in late spermatids and mature spermatozoa of Drosophila melanogaster: the role of oxygenation

The role of oxygenation in determining the sensitivity to the induction of dominant lethals was examined in late spermatids and mature spermatozoa of Drosophila melanogaster. 0–2-h-old or 7-day-old Oregon-K males were irradiated with different X-ray exposures in nitrogen, air or in oxygen and the frequencies of dominant lethals induced in these stages were studied. The results obtained confirm and extend Sobels' earlier observations and the interpretation derived therefrom namely, that under normal conditions in air, mature spermatozoa are characterised by a higher degree of oxygenation than late spermatids and this difference is sufficient to explain the differential response of these stages. Similar Oxygen-Enhancement-Ratios(OERs) (of about 2) were obtained for both the cell stages. The present data also revealed that late spermatids are significantly less sensitive than mature spermatozoa to the X-ray-induction of dominant lethals in a nitrogen atmosphere. A plausible mechanism is suggested to explain this observation.     

Comparison of the inhibitory potential towards carbonic anhydrase,acetylcholinesterase and butyrylcholinesterase of chalcone and chalcone epoxide

Chalcones and chalcone epoxides are important synthetic intermediates in organic and medicinal chemistry. Chalcones possess a broad spectrum of biological activities; however, 1,3‐diphenyl‐2‐propenone or chalcone has not been given the attention it deserve as its substituted derivatives. In this study, the inhibition effects of chalcone and its epoxidated derivative chalcone epoxide against human carbonic anhydrase isozymes I and II (hCA I and hCA II), acetylcholinesterase (AChE), and butyrylcholinesterase (BuChE) were evaluated. The results obtained showed that both compounds exhibited potent inhibitory activity, with IC₅₀ values less than 10 µM. IC ₅₀ values in the submicromolar (hCA I and hCA II) to low micromolar range (AChE and BuChE) were observed for both compounds. The mechanism of inhibition and the inhibitory constants ( K _i values) for each compound were also determined. Furthermore, chalcone epoxide was docked within the active sites of hCA I, hCA II, AChE, and BuChE to explore its binding mode with the enzymes.