Thyroxine effects on parameters of glucose turnover in BHE rats fed menhaden oil

The effect of hyperthyroidism on glucose turnover in BHE rats fed menhaden oil was studied. Thyroxine-treated rats had a greater glucose mass, a greater absolute glucose synthesis rate, less hepatic and muscle glycogen levels, and greater hepatic and peripheral fat cell lipogenic rates than nontreated rats. No differences in body weight gain were observed, nor were there differences in blood glucose levels, glucose space, or fractional reversible or irreversible glucose use. These observations suggest that thyroxine and menhaden oil were additive in their effects on glucose metabolism in BHE rats, which are genetically programmed to develop non-insulin-dependent diabetes mellitus.     

Purification and properties of arylmannosidases from mung bean seedlings and soybean cells

Two arylmannosidases (signified as A and B) were purified tohomogeneity from soluble and microsomal fractions of mung beanseedlings. Arylmannosidase A from the microsomes appeared thesame on native gels and on SDS gels as soluble arylmannosidaseA, the same was true for arylmannosidase B. Sedimentation velocitystudies indicated that both enzymes were homogeneous, and thatarylmannosidase A had a molecular mass of 237 kd while B hada molecular mass of 243 kd. Arylmannosidase A showed two majorprotein bands on SDS gels with molecular masses of 60 and 55kd, and minor bands of 79, 39 and 35 kd. All of these bandswere N-linked since they were susceptible to digestion by endo-glucosaminidaseH. In addition, at least the major bands could be detected byWestern blots with antibody raised against the xylose moietyof N-linked plant oligosaccharides, and they could also be labeledin soybean suspension cells with [2–3H]mannose. ArylmannosidaseB showed three major bands with molecular masses of 72, 55 and45 kd, and minor bands of 42 and 39 kd. With the possible exceptionof the 45 and 42 kd bands, all of these bands are glycoproteins.Arylmannosidases A and B showed somewhat different kineticsin terms of mannose release from high-mannose oligosaccharides,but they were equally susceptible to inhibition by swainsonineand mannostatin A. Polyclonal antibody raised against the arylmannosidaseB cross-reacted equally well with arylmannosidase A from mungbean seedlings and with arylmannosidase from soybean cells.However, monoclonal antibody against mung bean arylmannosidaseA was much less effective against arylmannosidase B. Antibodywas used to examine the biosynthesis and structure of the carbohydratechains of arylmannosidase in soybean cells grown in [2–³H]mannose.Treatment of the purified enzyme with Endo H released 50% ofthe radioactivity, and these labeled oligosaccharides were ofthe high-mannose type, i.e. mostly Man9GlcNAc. The precipitatedprotein isolated from the Endo H treatment still contained 50%of the radioactivity, and this was present in modified structuresthat probably contain xylose residues. Mung beans mannosidases glycoproteins -soybean--mannosidases xylose-containing N-linked glycoproteins     

Protoplast isolation and callus production from leaves of tissue-cultured Vitis spp.

Protoplasts were isolated from mesophyll of axenic cultures of grape, Vitis rotundifolia cv. Summit and V. vinifera cv. Cabernet Sauvignon. Enzymes effective for protoplast isolation were Macerozyme R-10 (0.5% and 0.1%) and Cellulase Onozuka R-10 (1.0% and 0.5%) for V. rotundifolia and V. vinifera, respectively. Polyvinylpyrrolidone and 2-(N-morpholino)ethanesulfonic acid were essential in the isolation media. Protoplasts were purified using flotation/centrifugation. The protoplasts of V. rotundifolia cultured in Gamborg's B5 basal medium with 2.2 M 6-benzyladenine, 4.5 M 2,4-dichlorophenoxyacetic acid and 0.4% agarose gave the best plating efficiency of conditions tried in this study. Cell division occurred within 5 to 6 days and visible microcalli developed within one month. After 6 weeks in culture, microcalli transferred to liquid medium exhibited active callus growth. Protoplasts of V. vinifera cultured under these conditions had similar results.Abbreviations MES 2-(N-morpholino)ethanesulfonic acid monohydrate - PVP polyvinylpyrrolidone - PDS potassium dextran sulfate - BA 6-benzyladenine - 2,4-D 2,4-dichlorophenoxyacetic acid - FDA fluorescein diacetate     

马铃薯Y病毒外壳蛋白基因的克隆及序列分析

本文报道应用聚合酶链式反应(PCR)技术,在体外扩增马铃薯 Y 病毒外壳蛋白基因及其克隆和序列分析的结果。病毒 RNA 从马铃薯 Y 病毒感染的烟草叶片中提取,用合成的PCR 3引物及 AMV 逆转录酶合成了单链的 cDNA。利用 PCR 技术,经30个循玎的扩增。得到了一特异的0.8kb 片段。克隆后对此片段进行了限制性内切酶物理图谱分析,并测定了其全序列。实验结果证明,我们克隆到的是完整的马铃薯 Y 病毒的外壳蛋白基因。与国外报道的马铃薯 Y 病毒 N 株相比,其核苷酸序列及推测的氨基酸序列的同源率分别为97.8%和97%。将该基因导入马铃薯以期获得抗 Y 病毒马铃薯的工作正在进行。本文还对 PCR 技术用于扩增植物 RNA 病毒的方法以及用基因工程方法培育抗病毒作物新品种的可行性等进行了讨论。     

Ammonium and nitrate uptake by barley genotypes in diurnally fluctuating root temperatures simulating till and no-till conditions

The morphological development and N uptake patterns of spring barley (Hordeum vulgare L.) genotypes of Northern European (Nordic) and Pacific Northwest US (PNW) origin were compared under two diurnally fluctuating root temperature regimes in solution culture. The two regimes, 15/5°C and 9/5°C day maximum/night minimum temperatures, simulated soil temperature differences between tilled vs. heavy-residue, no-till conditions, respectively, observed during early spring in eastern Washington. Previous field experiments indicated that some of the Nordic genotypes accumulated more N and dry matter than the PNW cultivars during early spring under no-till conditions. The objective of this experiment was to determined whether these differences 1) are dependent on the temperature of the rooting environment, and 2) are correlated with genotypic differences in NH₄ ⁺ and NO₃ ^– uptake. Overall, shoot N and dry matter accumulation was reduced by 40% due to lower root temperatures during illumination. Leaf emergence was slowed by 14 to 22%, and tiller production was also inhibited. All genotypes absorbed more ammonium than nitrate from equimolar solutions, and the proportion of total N absorbed as NH₄ ⁺ was slightly higher in the 9/5°C than the 15/5°C regime. A Finnish genotype, HJA80201, accumulated significantly more shoot N than the PNW cultivars, Clark and Steptoe, and also more than a Swedish cultivar, Pernilla, in the 9/5°C regime. In the 15/5°C regime Steptoe did not differ in shoot N from the Nordic genotypes, while Clark remained significantly lower. These differences were not correlated to relative propensity for N form. Root lengths of the Nordic genotypes were significantly greater than the PNW genotypes grown under the 9/5°C regime, while the root lengths in the warmer root temperture regime were not significantly different among genotypes. Higher root elongation rates under low soil temperature conditions may be an inherent adaptive mechanism of the Nordic genotypes. Overall, the data indicate that lower maximum daytime temperatures of the soil surface layer likely account for a significant portion of the growth reductions and lower N uptake observed in no-till systems.     

水生观赏植物的调查和研究

水生绿化观赏植物是美化园林水景的重要植物材料,作者通过几年的调查研究和引种栽培,提出了28种(其中荷花含18个品种,睡莲含20个品种)水生绿化观赏植物,同时介绍了20种(其中荷花含6个品种)观赏价值较高的水生绿化观赏植物。     

Isolation and partial sequence of goat spleen prothymosin α

Goat prothymosin , a highly acidic polypeptide of pl 3.5, 109 amino acid residues, has been isolated from lymphoid and non-lymphoid tissues of young female goats. Unlike rat, murine and porcine prothymosins , goat prothymosin appears at a higher concentration in the spleen compared with the thymus. The sequence of segments of the polypeptide involving known mutations has been determined, by automatic sequencing of its tryptic peptide fragments. The acidic amino acid-rich segment in the middle of the molecule, including residues 49–83, has not been sequenced. Goat prothymosin closely resembles bovine prothymosin , with only one substitution, proline for alanine at position 85. It also resembles human prothymosin , with only three substitutions. It differs more significantly from rat and murine prothymosins , by two deletions and three substitutions. The results show the highly conserved nature of the molecule, with substitutions at given positions only.Abbreviations ProT Prothymosin - T₁ Thymosin ₁ - MLR Mixed Lymphocyte Response - HPLC High Performance Liquid Chromatography - RIA Radioimmunoassay - B Aspartic acid or Asparagine - Z Glutamic acid or Glutamine     

室旁核在剌激猫肾神经传入纤维引起的血压效应中的应用

The purpose of this study is to investigate the role of paraventricular nucleus of the hypothalamus (PVN) and alpha 1 adrenergic receptor of PVN in the pressor responses to stimulation of renal afferent nerve in alpha 1-chloralose-anesthetized cats with carotid sinoaortic denervation and vagotomy. The pressor response to stimulation of renal afferent nerve consisted of a primary and a second components. The primary component response was completely blocked while the second component was not blocked by autonomic blocking agents (hexomethonium and atropine). Bilateral lesions of PVN greatly attenuated the pressor response before and after autonomic blockade. Intracerebroventricular and PVN injection alpha 1, adrenergic antagonist (prazosin) significantly decreased in the pressor response to stimulation of renal afferent nerve. These results indicate that paraventricular nucleus of the hypothalamus and alpha 1 adrenergic receptors in central nervous system, especially in PVN, play an important role in the pressor responses to stimulation of renal afferent nerve.