Synthesis of salt-soluble proteins in barley. Pulse-labeling study of grain filling in liquid-cultured detached spikes

The accumulation of salt-soluble proteins in the endosperm of developing barley (Hordeum vulgare L.) grains was examined. Detached spikes of barley were cultured at different levels of nitrogen nutrition and pulse-labeled with [¹⁴C] sucrose at specific times after anthesis. Proteins were extracted from isolated endosperms and separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and crossed immunoelectrophoresis. Fluorography revealed an early, middle and late synthesis of specific proteins during grain filling. Synthesis of proteins appearing at the later stages responded to increased nitrogen nutrition. Two major components, -amylase and protein Z in particular, had a synthesis profile almost identical to that of the endosperm storage protein, hordein.Abbreviations CIE Crossed immunoelectrophoresis - SDSPAGE Sodium dodecyl sulphate polyacrylamide gel electrophoresis     

Astrocytes enhance radical defence in capillary endothelial cells constituting the blood-brain barrier.

Astrocytes (AC) induce blood-brain barrier (BBB) properties in brain endothelial cells (EC). As antioxidative activity (AOA) is assumed to be a BBB characteristic, we tested whether AC improve AOA of EC. Monocultivated AC showed higher AOA [manganese superoxide dismutase (SOD), catalase (Cat), glutathione peroxidase (GPx)] than EC. Cocultivation elevated AOA in EC (MnSOD, CuZnSOD, Cat, GPx), and AC (MnSOD, CuZnSOD, GPx). Hypoxia increased radical-induced membrane lipid peroxidation in monocultivated, but not in cocultivated EC. Thus, EC/AC cocultivation intensifies AOA in both cell types, protects the EC, and therefore, the BBB against oxidative stress. The high AOA is regarded as an essential property of the BBB, which is induced by AC.     

Comparison of two methods for designing calorimeters using stirred tank reactors

Calorimetry is a robust method for online monitoring and controlling bioprocesses in stirred tank reactors. Up to now, reactor calorimeters have not been optimally constructed for pilot scale applications. Thus, the objective of this paper is to compare two different ways for designing reactor calorimeters and validate them. The “heat capacity” method based on the mass flow of the cooling liquid in the jacket was compared with the “heat transfer” method based on the heat transfer coefficient continuously measured in the cultivation of Escherichia coli VH33 in a 50 L stirred tank reactor. It was found that the values of the “heat transfer” method agreed very well with the calculated values from the oxygen consumption. By contrast, the curve of the “heat capacity” method deviated from that of the oxygen consumption calculated with the oxycaloric equivalent. In conclusion, the “heat transfer” method has been proven to have a higher degree of validity than the “heat capacity” method. Thus, it is a better and more robust means to measure heat generation of fermentations in stirred tank bioreactors on a pilot scale. Biotechnol. Bioeng. 2013; 110: 180–190. © 2012 Wiley Periodicals, Inc.     

Autoradiographische Untersuchungen über die zelluläre Verteilung von Cäsium-134 in der Skelettmuskulatur von Mäusen

Zusammenfassung Die zelluläre Verteilung von ¹³⁴Cs in der Skelettmuskulatur von Mäusen wurde histoautoradiographisch untersucht. 4–6 Std nach einer intraperitonealen Applikation von ¹³⁴CsCl zeigte sich eine starke Anhäufung der ¹³⁴Cs-Aktivität im Bereich des Sarkolemms. Die Aktivität folgte den Konturen der Muskelzellmembran, ein Befund, der auf eine Adsorption der Cs-Ionen an das Sarkolemm schließen läßt. Innerhalb der Myofibrillen zeigte sich eine an die Querstreifung erinnernde Anordnung der Schwärzungen.

---

Autoradiographic studies on the cellular distribution of ¹³⁴cesium in the skeletal muscle of mice

Summary The cellular distribution of ¹³⁴Cs in the skeletal muscle of mice was investigated by histoautoradiography. A relatively high accumulation of ¹³⁴Cs was found at the sarcolemma 4–6 hours after intraperitoneal application of ¹³⁴CsCl. This permits the conclusion that Cs-ions are probably adsorbed by the sarcolemma before they are moved into the muscle cell. Within the cell ¹³⁴Cs seems to be linked with myofibrils at destinct distances similar to those between isotropic and anisotropic bands.

     

马铃薯糖转运蛋白基因的克隆及表达分析

植物SWEET基因家族是一类糖转运蛋白,在植物的生理活动和生长发育过程中发挥着重要功能。为了解马铃薯SWEET基因的相关信息,探究其在马铃薯不同组织以及在生物胁迫与非生物胁迫下的表达特性。该研究采用同源克隆技术从马铃薯‘青薯9号’中克隆了StSWEET5基因(GenBank登录号为MN295671),其CDS序列长度为717 bp,编码238个氨基酸。系统进化树分析结果表明,StSWEET5与番茄的氨基酸序列相似性最高(97.06%)。qRT-PCR分析表明:StSWEET5基因在马铃薯各组织(根、茎、叶、花、块茎、匍匐茎)中均有表达,且在花中的表达显著高于其他组织;糖胁迫下,StSWEET5基因在根、茎、叶中均有表达,尤其在根中的表达差异最为显著(P0.05)。在晚疫病菌(Phytophthora infestans)诱导后36 h时,表达量达到最高,随后急剧下调。推测StSWEET5基因参与了马铃薯糖胁迫以及响应了晚疫病诱导的过程。     

Novel insights into the beneficial and detrimental actions of cdk5

In the adult brain, cyclin-dependent kinase 5 (Cdk5) can be beneficial by contributing to memory formation or can be detrimental by causing neurodegeneration, and it is of great interest to understand this dichotomy. Currently, it remains largely unknown which mechanisms are regulated by Cdk5. Recent studies by Hawasli et al. and Qu et al., however, are significant advances towards mechanistic insights. Hawasli et al. demonstrate that Cdk5 regulates protease-directed degradation of an important synaptic receptor, which impacts memory formation. Qu et al. show that Cdk5 inhibits the activity of an enzyme that metabolizes reactive oxygen species, which then leads to neurodegeneration. These two studies hold promise for establishing treatments to prevent cognitive dysfunction and neurodegeneration.     

Evaluation of the prevalence and economic burden of adverse drug reactions presenting to the medical emergency department of a tertiary referral centre: a prospective study

Background  

Adverse drug reactions (ADRs) are now recognized as an important cause of hospital admissions, with a proportion ranging from 0.9–7.9%. They also constitute a significant economic burden. We thus aimed at determining the prevalence and the economic burden of ADRs presenting to Medical Emergency Department (ED) of a tertiary referral center in India     

Influence of nutrients on enhancing laccase production by Botryosphaeria rhodina MAMB-05.

The physiological requirements needed to enhance the production of laccases by the ascomycete Botryosphaeria rhodina MAMB-05 in submerged cultivation were examined under non-induced and induced (veratryl alcohol, VA) conditions. Under non-induced conditions (-VA), the initial pH, C:N ratio, and inorganic N source did not influence laccase production, in contrast to Tween 80, soybean oil, and copper, which significantly increased laccase production, and proline and urea, which suppressed laccase formation. In addition, Tween 60 could serve as the sole carbon source for the production of these enzymes. Under VA-induced conditions of fungal growth, factors such as inoculum type, time-point of addition of inducer, initial pH, C:N ratio, and type of N source, influenced the production of laccases; however, unlike the non-induced conditions, proline and urea did not act as suppressors. Each of these physiological conditions exerted different effects on biomass production. The nutritional conditions examined for B. rhodina MAMB-05 are discussed in relation to their influence on fungal growth and laccase production.     

疣柄牛肝菌属一中国新记录种

报道了采自内蒙古呼伦贝尔市的中国疣柄牛肝菌属1个新记录种,即假褐疣柄牛肝菌Leccinum pseudoscabrum(Kallenb.)utara.。主要特征为菌肉伤后变红到紫褐色,再到黑褐色,基部菌丝体手触后呈紫褐色;具泡状菌丝,呈栅栏状。比较和讨论了该种与相近种在伤后不同的变色反应及菌丝形态。研究标本存放于吉林农业大学菌物标本馆(HMJAU)。     

Targeting extracellular domains d4 and d7 of vascular endothelial growth factor receptor 2 reveals allosteric receptor regulatory sites

Vascular endothelial growth factors (VEGFs) activate three receptor tyrosine kinases, VEGFR-1, -2, and -3, which regulate angiogenic and lymphangiogenic signaling. VEGFR-2 is the most prominent receptor in angiogenic signaling by VEGF ligands. The extracellular part of VEGF receptors consists of seven immunoglobulin homology domains (Ig domains). Earlier studies showed that domains 2 and 3 (D23) mediate ligand binding, while structural analysis of dimeric ligand/receptor complexes by electron microscopy and small-angle solution scattering revealed additional homotypic contacts in membrane-proximal Ig domains D4 and D7. Here we show that D4 and D7 are indispensable for receptor signaling. To confirm the essential role of these domains in signaling, we isolated VEGFR-2-inhibitory "designed ankyrin repeat proteins" (DARPins) that interact with D23, D4, or D7. DARPins that interact with D23 inhibited ligand binding, receptor dimerization, and receptor kinase activation, while DARPins specific for D4 or D7 did not prevent ligand binding or receptor dimerization but effectively blocked receptor signaling and functional output. These data show that D4 and D7 allosterically regulate VEGFR-2 activity. We propose that these extracellular-domain-specific DARPins represent a novel generation of receptor-inhibitory drugs for in vivo applications such as targeting of VEGFRs in medical diagnostics and for treating vascular pathologies.