Arbuscules of vesicular-arbuscular mycorrhizal fungi inhabit an acidic compartment within plant roots

 The most widespread type of mycorrhiza is the so-called vesicular-arbuscular mycorrhiza. In this endomycorrhiza, fungal hyphae penetrate plant cell walls in the root cortex. There they form densely branched arbuscules. Fungus and plant plasma membrane are separated by a common interfacial apoplast. The pH of the compartment between the symbionts is of pivotal importance for nutrient transfer. Histochemical experiments were conducted to check for an acidic nature of the interface in the model system Glomus versiforme (Karst.) Berch-Allium porrum L. Two chemically different acidotropic dyes (neutral red and LysoSensor Green DND-189) stained the arbuscules intensely. The staining of arbuscules could be eliminated by addition of the protonophore carbonylcyanide m-chlorophenylhydrazone (CCCP) or treatments leading to membrane rupture. Therefore, the staining of the arbuscules was based on the ion-trap mechanism, which indicates acidic, membrane-bound compartments. Microscopic examination of stained arbuscules at high optical resolution revealed a peripheral accumulation of the dye. Since plasmolysis rapidly destained the arbuscules, it is concluded that the dyes accumulate in the arbuscular interface, indicating the highly acidic nature of this compartment. The findings are discussed with respect to their relevance for the nutrient transfer in mycorrhizas. In addition, evidence for a discontinuity in the arbuscular interface between the stem and the branches of the arbuscule is given. Received: 15 September 1999 / Accepted: 20 February 2000     

Vital staining permits isolation of calcium vesicles from the green alga Mougeotia

The calcium vesicles of the green alga Mougeotia (G. Wagner and R. Rossbacher, 1980, Planta 149, 298–305) were isolated for characterization in vitro by fractionation of algal homogenate on sucrose density gradients. A new technique, based on vital staining by neutral red or rhodamine B, permitted isolation. Minimum dye binding to the calcium vesicles prevented desintegration, and for isolation a single, thoroughly defined centrifugation step sufficed, facilitated by the exceptionally high vesicular density of 1.3 g· cm^-3. Neutral red in particular seems to be accumulated by the vesicles via hydrogen bonds to abundant phenolic hydroxyl groups which, reversibly bound to an as yet undefined vesicle core, may well provide coordination sites for the observed calcium binding.Dedicated to Professor Wilhelm Nultsch on the occasion of his 60th birthdayA preliminary version of this paper has been presented at Tagung der Deutschen Gesellschaft für Zellbiologie (Grolig and Wagner 1985). This paper is part of the Ph. D. thesis of F. Grolig at Justus-Liebig-Universität Giessen     

大鼠活体注射台盼蓝后肝和肾的组织学与组织化学变化的观察

大鼠连续4天腹腔注射1%台盼蓝后,观察隔天、隔周、隔二周后肝和肾的组织结构及PAS、AlP、AcP、G-6-Pase、Mg~(2+)-ATPase和SDH的活性变化。结果发现:肝细胞和肾小管的上皮细胞中有台盼蓝颗粒;肝PAS反应阴性;隔天后肝AlP、AcP、G-6-Pase和SDH活性增强,Mg~(2+)-ATPase活性减弱;肾的上述组化反应活性都减弱;隔二周后肝和肾的上述组化反应接近对照。实验结果提示:活体注射台盼蓝对肝和肾未构成实质性损伤,隔天后的组化变化可能是一种生理适应性反应。     

Die Bildung der Gehäusewand bei der Thekamöbe Centropyxis discoides (Rhizopoda,Testacea)

Zusammenfassung Die Gehäusewand von Centropyxis discoides besteht aus 1–4 Lagen von polygonalen Alveolen. Jeder Alveolus geht durch direkte Transformation aus einem thekagenen Granum hervor. Eine cytoplasmatische Knospe ist die Anlage einer neuen Schale, welche als erster Schritt der Zweiteilung für einen der beiden Abkömmlinge gebildet wird. Noch vor der Kernteilung werden die thekagenen Grana in die Anlage transportiert und abgeschieden. Bei der Extrusion erreichen einige Grana sogleich die Oberfläche der Anlage. Die meisten Grana finden sich jedoch in einem extrazellulären Lakunensystem, welches die Knospe zu einem schwammähnlichen Netzwerk auflockert. Schließlich gelangen auch sie an die Oberfläche. Dort werden die Grana zu Alveolen aufgebläht, die aneinanderkleben. Die Knospe ist von dem alten Gehäuse durch eine Cytoplasmaschicht getrennt, die mit der Hauptportion des Anlage-Cytoplasmas bei der Sekretion der ventralen Wand des neuen Gehäuses zusammenwirkt. Daher ist die ventrale Wand eine aus Alveolen zusammengesetzte Struktur, die von zwei Seiten sezerniert wurde, während die übrigen Regionen der jungen Schale nur aus thekagenen Grana aufgebaut werden, die aus dem Inneren der Anlage auftauchten.

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The formation of the thecal wall in Centropyxis discoides (rhizopoda, testacea)

Summary The thecal wall of Centropyxis discoides consists of 1–4 layers of polygonal alveoli. Each alveolus originates by direct transformation from a single thecagenous granule. These granules are extruded prior to nuclear and cell division from a cytoplasmic bud, which is the anlage of a new test to be formed for one of the two offsprings. During extrusion, some of the granules reach the surface of the anlage immediately, but most of them are at first found in an extracellular system of lacunae penetrating the bud as a sponge-like network. Finally, they also reach the surface, where they enlarge and stick together. The bud is separated from the old shell by a layer of cytoplasm, which collaborates with the main portion of anlage-cytoplasm in secreting the ventral wall of the new test. Hence, the ventral wall is a structure composed of alveoli, that have been secreted from two sides, whereas the other regions of the young shell are composed of thecagenous granules emerging only from within the anlage.

Mit Unterstützung durch die Deutsche Forschungsgemeinschaft; gefördert durch den Sonderforschungsbereich 53 Paläontologie unter besonderer Berücksichtigung der Palökologie, Tübingen. — Stereoscan-Aufnahmen: Rosemarie Freund. Technische Assistenz: Barbara Grunewald.     

Characterization of cap-shaped silver particles for surface-enhanced fluorescence effects

Surface-enhanced fluorescence has potentially many desirable properties as an analytical method for medical diagnostics, but the effect observed so far is rather modest and only in conjunction with fluorophores with low quantum yields. Coupled with the fact that preparation of suitable surfaces at low costs has been difficult, this has limited its utilities. Here we report a novel method for forming uniform and reproducible surfaces with respectable enhancement ratios even for high-quantum-yield fluorophores. Formation of dense surface-adsorbed latex spheres on a flat surface via partial aggregation, followed by evaporation of silver, results in a film consisting of cap-shaped silver particles at high densities. Binding of fluorescence biomolecules, either through physisorption or antigen-antibody reaction, was performed, and enhancements close to 50 have been observed with fluorophores such as R-phycoerythrin and Alexa 546-labeled, bovine serum albumin, both of which have quantum yields around 0.8. We attribute this to the unique shape of the silver particle and the presence of abundant gaps among adjacent particles at high densities. The effectiveness of the new surface is also demonstrated with IL-6 sandwich assays.     

改良的肥大细胞甲苯胺蓝染色法

目的:本研究旨在运用一种改良的甲苯胺蓝染色方法鉴定体外分离培养的肥大细胞形态,为肥大细胞研究提供简便的检测方法。方法:体外诱导分化培养小鼠骨髓来源的肥大细胞,4周后收集细胞、固定、染色。比较不同固定温度及时间对甲苯胺蓝染色效果的影响,确定最佳条件。结果:SCF和IL-3体外培养诱导出小鼠骨髓来源肥大细胞。肥大细胞用改良的甲苯胺蓝染色后细胞着色效果较好,细胞多呈圆形或椭圆形且胞膜较完整,胞浆中充满大量的紫红色颗粒。结论:本研究成功运用一种适用于体外培养小鼠骨髓源肥大细胞的甲苯胺蓝染色法,并发现肥大细胞在37℃充分固定后进行染色,可以降低肥大细胞发生脱颗粒。此操作方法稳定性好、简便,适用于体外培养的肥大细胞形态学观察。     

丹蛭降糖胶囊联合硫辛酸、依帕司他对气阴两虚夹瘀型糖尿病周围神经病变患者血糖水平和下肢神经功能的影响

摘要 目的：探讨丹蛭降糖胶囊联合硫辛酸、依帕司他治疗气阴两虚夹瘀型糖尿病周围神经病变（DPN）的临床疗效,并分析其对血糖和下肢神经功能的影响。方法：按照随机数字表法将81例DPN患者分成对照组40例和观察组41例,对照组在2型糖尿病治疗基础上使用硫辛酸静滴联合依帕司他口服治疗,观察组在对照组治疗基础上,加用丹蛭降糖胶囊口服治疗。比较两组治疗前后中医证候积分、双下肢肌电图[腓总神经运动神经传导速度（MCV）、腓肠神经感觉神经传导速度（SCV）]、电流感觉阈值（CPT值）、血糖指标[空腹血糖（FPG）、餐后2小时血糖（2 hBG）、糖化血红蛋白（HbA1c）]水平变化,并对比两组总有效率和治疗方案安全性。结果：观察组总有效率为90.24%（37/41）,明显高于对照组的70.00%（28/40）,差异有统计学意义（P＜0.05）;治疗8周后,两组肢体麻木、肢体末梢疼痛、神疲乏力、气短懒言、腰膝酸软、失眠烦躁积分,FPG、2 hBG、HbA1c水平均明显降低（P＜0.05）,且观察组各项中医证候积分和血糖指标水平均明显低于对照组（P＜0.05）;治疗8周后,观察组相同频率正弦交流电刺激下的第一脚趾远端趾节甲小皮基部近端的CPT值均明显低于对照组（P＜0.05）,腓总神经MCV、腓肠神经SCV均明显高于对照组（P＜0.05）;两组治疗过程中均未发生明显药物不良反应。结论：丹蛭降糖胶囊口服联合硫辛酸、依帕司他治疗气阴两虚夹瘀型DPN,能够有效缓解患者的临床症状和体征,控制血糖水平,改善下肢神经功能,疗效明显优于单纯西药治疗,且安全性高。     

Mass-transfer based modeling to investigate iodine staining effects for enhanced contrast X-ray computed tomography

Iodine staining combined with X-ray computed tomography (CT) has become a core approach in anatomy, offering three-dimensional and essentially non-destructive imaging of soft tissues. Although there have been rapid advances in methodologies and techniques, the mechanisms underlying diffusible iodine contrast-enhanced CT are not yet fully understood. The protocols for staining samples of differing sizes and tissue types have not yet been justified theoretically. Here we utilize mass transfer modeling to simulate iodine diffusion and predict iodine concentrations within distinct tissue types. We also undertake iodine staining experiments to visualize the detailed anatomy and contrast effects on whole-body avian specimens using different concentrations of iodine solution to compare with model simulation results. The simulations effectively explain most observed concentration changes in differently-sized samples over distinct iodine treatment durations. These results also provide insight into the mechanisms behind the efficacy of solution replenishment for enhancing staining effects. Both consistencies and inconsistencies between our simulation and experimental results regarding iodine concentration in tissues will inform further investigations to optimize iodine staining protocols.     

Standardized staining methods: Feulgen-Rossenbeck reaction for desoxyribonucleic acid and periodic acid-Schiff (PAS) procedure

A project group working under the European Confederation of Laboratory Medicine (ECLM) presents recommendations for standardized procedures for the Feulgen-Rossenbeck-Schiff and the periodic acid-Schiff (PAS) reactions on cytological and histological material. The advantages and disadvantages of such standardized procedures are presented here in a preamble. Both users and manufacturers are encouraged to give their opinions with a view to achieving consensus on these procedures and on how further work on these lines may proceed.     

Moniezia expansa: Subcellular distribution,kinetic properties of acetylcholinesterase and effects of inhibitors and anthelmintics

Acetylcholinesterase (EC 3:1:1:7) has been demonstrated biochemically within partially purified whole worm homogenates of Moniezia expansa. Linear activity occurred with temperature, enzyme concentration, and time. The pH optimum was 8.5 and the Michaelis constant 2.8 mM with inhibition by excess substrate. Inhibitor and specific substrate studies indicated that butyrylcholinesterase was probably absent. The molecular weight of AChE was in excess of 300,000. Greatest activity occurred in the 22,000 and 100,000g particulate fractions. Ultrastructural staining showed that activity was restricted to the ribosomes and cisternae of the rough endoplasmic reticulum. Quinacrine hydrochloride caused 48% inhibition of AChE at 10^?3M and haloxon (di(2-chloroethyl)-3-chloro-4-methyl-7-coumarinyl phosphate) caused 97% inhibition at 10^?4M. No appreciable inhibition (< 25%) occurred with 10^?4M bunamidine hydroxynaphthoate, bephenium hydroxynaphthoate, pyrantel tartrate, p-toluoyl phenyl hydrazone, dichlorphen, thiabendazole, mebendazole, fenbendazole, cambendazole, albendazole, parbendazole, oxibendazole, oxfendazole, praziquantel, piperazine adipate, arecoline hydrobromide, and sodium acetarsol.