测定糖尿病患者血清LDL-C水平的方法学比较

目的：比较不同方法检测糖尿病患者血清LDL-C水平,为临床诊疗提供准确可行的检验方法。方法：采用沉淀法、匀相法、电泳法及超速离心法对233例糖尿病患者和102例健康人群的血清LDL-C水平进行测定,比较各方法之间的相关性,同时分析导致结果差异的因素。结果：四种方法检测健康人群LDL-C水平,结果间无统计学差异（P〉0.05）;糖尿病组,当TG≤2.26mmol/L时,四种方法检测LDL-C结果间相关性良好。高胆红素、血红蛋白、高TG及乳糜等干扰因素存在时,与其他方法相比,电泳法和超速离心法检测血清LDL-C结果受影响较小（P〉0.05）。结论：超速离心法虽耗时、价格贵,但仍为检测LDL-C的经典方法,电泳法受高胆红素、血红蛋白、高三酰甘油等干扰因素的影响相对较小,适用于糖尿病合并高血脂患者血清LDL-C水平检测。     

Reserve Lipids in Stem Root Primordia of Poplar

Lipids are reserve substances in stem root primordia of poplarand occur as droplets approximately uniformly in all cells ofroot primordia. In ultrathin sections they appear as sphericalelectron-dense particles (0.5–1.4 µm diameter),filling up virtually all the available space in the cytoplasm.The presence of lipids in stem root primordia was demonstratedin several species of the genus Populus from the section Aigeirosand Tacamahaca, as well as in another representative of thefamily Salicaceae, viz. in the genus Salix.     

A Comparison of Two Methods for Obtaining Anaerobic Counts in Different Segments of the Gastro-intestinal Tract of Piglets

S ummary . The total anaerobic count on contents of the gastro-intestinal tract of 7 piglets, fed on a milk powder diet, was determined with the ringed plates technique of Van der Heyde and the roll tube method of Hungate. Simultaneously, the oxidation-reduction potential ( E_h ) was measured in the different segments. For caecal and large intestinal contents, higher counts were obtained with the roll tube method. Nevertheless, the proportional composition of the dominant flora was identical for both methods. Marked differences between the E_h of the different gastro-intestinal segments were observed.     

Estimation of Conductivity and Conducting Area of Poplar Stems using a Radioactive Tracer

Radioactive solution was forced through stems of poplar underknown pressures. The velocity of the solution was monitoredby Geiger tubes spaced along the stem, and by dividing velocityinto the rate at which the solution was seen to exude from thedistal end, the total cross-sectional area of the functionalconduits was estimated. This amounted to 13 per cent of thecross-sectional area of the vessels. A value of 9.5±0.6 x 10^–9 m⁴s^–1N^–1was obtained for the conductivity with a range of 4.0–22.3X 10^–9 m⁴s^–1N^–1.     

Regulation of Growth in Avena Stem Segments by Gibberellic Acid and Kinetin

Kinetin at physiological concentrations causes significant reduction of GA₃-promoted growth in excised Avena stem segments. Kinetin is therefore considered to be a gibberellin-antagonist in this system. A Lineweaver-Burke plot reveals that kinetin acts non-competitively with GA₃. The kinetin inhibition of GA₃-promoted growth can be seen within 6 hours. It was found that soluble protein is markedly increased by kinetin in the tissue during the first 3 hours, thus preceding the inhibition of GA₃-promoted growth by several hours. At the cellular level, kinetin negated the blocking effect of GA₃ on cell division in the intercalary meristem portions of these segments. In fact, kinetin promotes both lateral and longitudinal cell divisions in intercalary meristem cells.     

Involvement of Calcium in Adventitious Bud Initiation in Torenia Stem Segments

In Torenia stem segments cultured in vitro, active meristematicdivisions are induced in the epidermis by treatment with cytokinin,resulting in the formation of adventitious buds. Applicationof the calcium ionophore A23187 [GenBank] was found to induce meristematicdivisions in the absence of cytokinin. The induction by A23187 [GenBank] was inhibited by simultaneous addition of auxin, but not byanti-cytokinin. A two hour pre-treatment with A23187 [GenBank] was alsoeffective, but only when it was applied to the explants justafter their excision from mother plants. The A23187 [GenBank] -inducedmeristematic zones developed into dome-shaped structures, butnot into complete adventitious buds. Complete elimination ofcalcium from the culture medium caused 50% inhibition of A23187 [GenBank] -and/or cytokinin-induced initiation of meristematic divisions.When the explants were preincubated with EGTA and then culturedon a Ca-free medium containing EGTA, cytokinin failed to inducebud initiation. Similar inhibition was also obtained by lanthanum,a calcium antagonist, by verapamil, a calcium channel inhibitor,and by trifluoperazine and chlorpromazine, calmodulin inhibitors.These results support the idea that adventitious bud initiationinduced by cytokinin in Torenia stem segments may be mediated,at least partially, by an increase in the level of intracellularCa²⁺. ¹Bioscience Research Center, Mitsui Petrochemical IndustriesLtd., Waki-cho, Kuga-gun, Yamaguchi 740, Japan. (Received May 9, 1985; Accepted October 5, 1985)     

铁皮石斛茎段诱导丛生芽的研究

以铁皮石斛Dendrobium candidum Wall.ex Lindl.的茎段作外植体,比较不同的培养基、激素等因素对茎段分化丛生芽的影响,以及不同浓度的香蕉汁和活性炭对试管苗生根的影响。结果表明：1／2MS较好,BA作用优于KT、ZT,最适浓度为2．0mg/L;丛生芽培养于1／2MS 10％香蕉汁 0．5％AC的培养基上,生根效果最好。     

印楝茎段愈伤组织诱导及其植株再生

1 植物名称印楝(Azadirachta indica). 　　2 材料类别实生苗茎段. 　　3 培养条件诱导培养基:(1)MS 6-BA 1.0 mg*L-1(单位下同) NAA 0.01 3%蔗糖.增殖培养基:(2)MS 6-BA 0.5 NAA 0.1 3%蔗糖.生根培养基:(3)1/2MS NAA 0.01 1.5%蔗糖.每种培养基均附加0.7%琼脂,pH 5.8～6.0.培养温度23～27℃,光照时间12 h*d-1,光照度1 500～2 000 lx.……     

Polarity of Xylem Formation in Isolated Stem Segments of Pinus silvestris

The culture of isolated stem sogments was used as a technique to study polarity of xylem formation in Pinus silvestris L. Cambial activity was greatest at the apical or the basal end, whichever received the complete fresh medium, but decreased more abruptly with increasing distance when the basal end was so supplied. Whether gradients of activity increased basipetally or acropetally also depended upon the end to which the auxin and the sugar components were supplied. Ring-barking of segments, then cultur-ing them with apical supply of medium to the xylem, resulted in inhibition of xylem production below, and above, the ring. Cambial activity at the apical ends of such segments was expressible as a logarithmic function of the uninterrupted length of contiguous extraxylary tissues. The involvement of polarity phenomena in control of cambial activity in isolated stem segments is confirmed.     

康乃馨茎段愈伤组织诱导及植株再生(简报)

以康乃馨无菌苗茎段为外植体,在MS 6-BA 0.5mg/L NAA0.2mg/L培养基上诱导产生愈伤组织,愈伤组织在MS 6-BA 0.5mg/L NAA 0.2mg/L培养基上诱导芽效果较好,芽苗在1/2MS NAA 0.1mg/L培养基上可诱导生根。     

植物体中一氧化氮的检测方法及其应用

文章介绍植物体中NO的各种检测方法及其应用的研究进展。     

灯盏花茎段的离体培养和植株再生

1植物名称灯盏花(Erigeronbreviscapus). 2材料类别当年生茎段. 3培养条件以MS为基本培养基.(1)芽诱导培养基:MS;(2)芽增殖培养基:MS 6-BA 1 mg.L-1(单位下同);(3)生根培养基:2/3MS NAA 0.3.上述培养基均添加3%蔗糖、0.5%琼脂,pH 5.8.培养温度为23～25℃,光照度为2 000 lx,光照时间为12～14 h.d-1.     

Involvement of Cyclic AMP in Adventitious Bud Initiation of Torenia Stem Segments

Adventitous bud initiation in epidermis of Torenia stem segmentscultured in vitro, which is usually induced by cytokinin, couldbe induced by application of dibutyryl cyclic AMP in the absenceof cytokinin. Similar stimulatory effects on bud initiationwere observed when various promoting reagents to accumulateendogenous cyclic AMP were added, such as activators for adenylatecyclase, forskolin and prostaglandin E₁, and inhibitors of cyclicnucleotide phospho-diesterase, theophylline and isobutyl methylxanthine. Endogenous content of cyclic AMP in Torenia stem segmentswere increased by the application of the above chemicals, calciumionophore or cytokinin. These results suggested that endogenousconcentrations of cyclic AMP were involved in adventitious budinitiation of Torenia stem segments. Furthermore, some inhibitorsof protein kinases inhibited bud initiation induced by cyclicAMP-accumulating reagents. (Received August 15, 1989; Accepted November 4, 1989)     

西南金丝桃茎段的离体培养和植株再生

1　植物名称　西南金丝桃 (Hypericumhenryi)。2　材料类别　当年生茎段。3　培养条件　以MS为基本培养基。 ( 1 )腋芽诱导培养基 :MS + 6 BA 1 .0mg·L- 1 (单位下同 ) ;( 2 )芽增殖培养基 :MS + 6 BA 1 .0 +KT 1 .0 ;( 3)生根培养基 :1 /2MS。上述培养基均添加 3%蔗糖、0 .65 %琼脂 ,pH 5 .8～ 6.0。培养温度为 2 4℃ ,每日光照1 2～ 1 4h ,光照度 1 5 0 0lx。4　生长与分化情况4.1　芽的诱导　野外采集的茎段用常规法灭菌后 ,切成 2cm长的小段 (带 1个节 ) ,基部向下直插于 ( 1 )号培养基上。培养 5d后 ,腋芽开始萌动生长 ;1 5d后…     

Light-dependent Elongation of Anaerobically Maintained Green Pea Stem Segments and Its Implications

Anaerobic conditions reversibly inhibit the elongation of isolated green pea (Pisum sativum L. var Alaska) stem segments. Illumination of segments maintained under anoxia causes a resumption of growth. Polarographic studies show pea stem segments are photosynthetically competent as determined by O₂ evolution. Although O₂ production is totally inhibited by dichlorophenyldimethylurea (DCMU) and dinitrophenol (DNP) inhibits O₂-dependent growth, neither DCMU nor DNP completely abolishes light-dependent growth, although both reduce the effect markedly. Phenazine methosulfate promotes the growth of anaerobically maintained, illuminated, DCMU-treated segments. The data indicate that the principal effect of light in inducing growth under anaerobic conditions is the photosynthetic provision of O₂ for respiration. There is also some evidence that, at least in the absence of O₂, a small amount of elongation is due to some other light-driven process, perhaps cyclic photophosphorylation.     

Identification and Characterization of circRNAs in the Developing Stem Cambium of Poplar Seedlings

Molecular Biology - Non-coding RNAs are a class of RNAs with multiple roles in plant life. Covalently closed circular RNA molecules (circRNAs) have been recently shown to be a group of RNA isoforms...     

Evaluation of Methods for Determining Internal Gases in Banana Fruit

Two methods for sampling the gaseous atmosphere in the intercellularspaces of banana fruit pulp are described. One method removedthe sample directly using a syringe, the other allowed equilibrationof gases in the sample volume with the intercellular spacesby sealing a canula into the fruit. The effects of the methodsused were shown to be small in relation to a treatment withTAL Pro-long coating which depressed the oxygen and elevatedthe ethylene contents of the fruit. Key words: Banana, Internal atmosphere, Coating     

Significance of Spermidine in the Initiation of Adventitious Buds in Stem Segments of Torenia

When stem segments of Torenia fournieri Lind. were culturedin vitro, the initiation of adventitious buds, which is usuallyinduced by cytokinin, was induced by application of polyamines,such as putrescine and spermidine. Addition of arginine hada slight inductive effect. When cyclohexylamine, an inhibitorof spermidine synthase, was added simultaneously with putrescine,induction of the initiation of buds by putrescine was stronglyinhibited. However, application of the inhibitor together withspermidine had no effect on the spermidine-induced initiationof buds. The induction of initiation of buds by a cytokinin,by a calcium ionophore, by cyclic AMP, and by a phorbol ester,which was accompanied in each case by elevation of the levelsof endogenous spermidine, was also inhibited by cyclohexylamine.These results suggest the involvement of spermidine in the initiationof adventitious buds in stem segments of Torenia. ²Present address: Radiation Effects Research Foundation, Hijiyamakouen5-2, Minami-ku, Hiroshima, 732 Japan.