Inhibition of cell growth in vitro by adenosine 3',5'-monophosphate

Adenosine 3',5'-monophosphate, at a concentration of 40 micrograms per milliliter, inhibits the growth of HeLa and strain L cells in culture. The inhibition becomes progressively greater during the incubation of the cells. Adenosine 5'-monophosphate and adenosine, metabolites of adenosine 3',5'-monophosphate, do not affect the growth of either cell culture. This suggests that 3',5'-monophosphate enters the cell without alteration. Dibutyryl-adenosine 3',5'-monophosphate, reported to have a greater activity than adenosine 3'5'-monophosphate on several tissues, inhibited the growth of the cells much less.     

猪羊生长激素基因保守性研究

生长激素基因在猪羊间的差异 ,通过两对引物 ,分别为P1:5’ -agctggattctttacggctgagcc - 3’和P2 :5’ -tccggaagcaggagagcagaccgtag - 3’ ,P3:5’ -gctgacacctacaaggagtttg - 3’和P4:5’ - gtttgcttgaggatctgtcctg - 3’。对它们的DNA进行聚合酶链反应 ,电泳及序列分析结果表明 :P1-P2和P3-P4引物都能扩增出猪羊DNA样 ,得到大小一致的扩增带 (对应引物的带 ) ,但southern杂交结果的差别很大 ;生长激素基因的碱基组成在猪羊间的差异为 6 5 % ,即猪羊生长激素基因保守性很强     

Thyroid-stimulating hormone and prostaglandin E1 stimulation of cyclic 3',5'-adenosine monophosphate in thyroid slices

Thyroid-stimulating hormone increased the cyclic 3',5'-adenosine monophosphate concentration in dog thyroid slices during a 1-minute incubation period and produced a maximum effect soon thereafter. The elevation persisted for at least 30 minutes. The concentrations of the cyclic 3',5'-adenosine monophosphate increased as the TSH concentration was increased from 0.125 to 50 milliunits per milliliter. Prostaglandin E(1), which increases glucose oxidation in dog thyroid slices, also increased the concentration of cyclic 3',5'-adenosine monophosphate. Although sodium fluoride stimulates thyroid adenyl cyclase, it did not increase concentration of cyclic 3',5'-adenosine monophosphate. Carbamylcholine and menadiol sodium diphosphate augment glucose oxidation in dog thyroid slices but do not change concentrations of cyclic 3',5'-adenosine monophosphate.     

Early chemical evolution of nucleic acids: a theoretical model

Recent experimental work suggests a possible cyclical pathway for early prebiotic oligonucleotide formation that involves (i) dry-state (nontemplate) synthesis of random copolymers with mixed 2',5' and 3',5' bonds, (ii) passage of these oligomers into solution at low temperatures, and (iii) a preferential hydrolysis of the 2',5' bond in any short helices that have formed. This early system could have selected for complementary sequences that were largely 3',5'-linked, but may not have selected efficiently for a single enantiomer of ribose.     

Cyclic adenosine monophosphate stimulation of axonal elongation

Elevated concentrations of adenosine 3',5'-monophosphate induce a variety of cell movements. The role of adenosine 3',5'-monophosphate in promoting those movements associated with growth prompted our study of in vitro microtubule-dependent axonal elongation. Ganglia treated with adenosine 5'-monophosphate show no enhancement over controls; treatment with adenosine 3', 5'monophosphate or its dibutyryl derivative significantly enhances elongation, as measured by increases in both axonal numbers and length. Our study suggests that adenosine 3',5'-monophosphate promotes elongation by stimulation of microtubule assembly.     

Adenosine 3',5'-monophosphate in pancreatic islets: glucose-induced insulin release

Glucose-induced release of insulin from perifused rat islets is associated with elevated islet adenosine 3',5'-monophosphate. If values for adenosine 3',5'-monophosphate are compared to insulin release during theophylline or glucose stimulation and theophylline plus glucose stimulation, it suggests a minor role for adenosine 3',5'-monophosphate in directly stimulating insulin release but a prominent role in modulating glucose-induced release of insulin.     

抗草甘膦转基因油菜品种RG1和RG2的抗性测定

以转基因抗除草剂油菜RG1、RG2及陇油5号(CK)为材料,通过盆栽试验鉴定RG1、RG2及陇油5号对草甘膦的抗性.结果表明RG1、RG2对草甘膦具有很强的抗性,当草甘膦的喷施浓度达到4 000 mg/L时,RG1和RG2油菜可以正常生长.在甘肃永登县区域试验中,RG1和RG2的产量分别为3 952.5 kg/hm2和3 561.0 kg/hm2;在甘肃靖远县区域试验中RG1、RG2产量分别为3847.3 kg/hm2和3 535.0 kg/hm2.相比之下,陇油5号(CK)在永登县和靖远县的产量分别为3 568.5 kg/hm2和3 584.0 kg/hm2.     

Adenosine 3',5'-monophosphate: electrophysiological evidence for a role in synaptic transmission

Synaptic potentials and changes in resting membrane potentials of superior cervical ganglia of the rabbit were measured in the presence of adenosine 3',5'-monophosphate and agents that affect its metabolism. Adenosine 3',5'-monophosphate and its mono- and dibutyryl derivatives caused a hyperpolarization of the postganglionic neurons. Theophylline potentiated the slow inhibitory postsynaptic potential that follows synaptic transmission, as well as the hyperpolarization of postganglionic neurons caused by exogenous dopamine. Conversely, prostaglandin E(1) inhibited both the slow inhibitory postsynaptic potential and the dopamine-induced hyperpolarization. We hypothesize that the slow inhibitory postsynaptic potential as well as the dopamine-induced hyperpolarization result from increased amounts of adenosine 3'5'-monophosphate in the postganglionic neurons. The dibutyryl derivative of guanosine 3'5'-monophosphate caused a depolarization of the postganglionic neurons, which is consistent with the possibility that guanosine 3'5'-monophosphate mediates synaptic transmission at muscarinic cholinergic synapses.     

晚熟玉米杂交种灰色关联度分析

采用灰色关联度的分析方法,对适应吉林省种植的2000年以后各省审定的29个晚熟玉米杂交种11个主要性状指标进行综合分析和评价,得出这些品种与理想品种的灰色关联度从大到小为:吉单28>吉单257>吉玉4>登海9>正大29>豫奥3>铁单15>吉单29>东单8>平玉5>铁单19>富友1>丹玉29>济单7>吉东2>豫玉32>登海3619>农大84>四单167>原单29>登海3>平安20>沈单18>沈单16>豫玉22>东单11号>沈玉17>沈单12>沈单13。     

凡纳滨对虾总RNA完整性的正确评估

凝胶电泳技术通常被用于总RNA完整性检测,一般认为28S和18S rRNA条带亮度的比值大于等于2表示总RNA完整性良好,该比值越小表明总RNA降解越严重。为了检测这一标准在水产虾蟹类中是否继续适用,分别对凡纳滨对虾rRNA和mRNA的完整性进行了分析。用TRIzol分离纯化的凡纳滨对虾总RNA经凝胶电泳检测,发现其28S:18S rRNA的比值远小于2;但是以同样的总RNA为模板进行RT-PCR,能顺利扩增出长约1 100 bp的ACT和eEF1A基因序列。进一步的3':5'分析显示这2个内参基因mRNA的3':5' ratio分别为2.79和1.53,直接表明被测mRNA完整性良好。因此,凝胶电泳低估了水产虾蟹类总RNA的完整性,建议采用3':5'分析技术对水产虾蟹类总RNA完整性进行检测。     

Fluorescent modification of adenosine 3',5'-monophosphate: spectroscopic properties and activity in enzyme systems

The synthesis of a highly fluorescent analog of adenosine 3',5'-monophosphate, namely, 1,N(6)-ethenoadenosine 3',5'-monophosphate, has provided a powerful probe for systems involving adenosine 3',5'-monophosphate. The potential utility of this analog is indicated by its long fluorescent lifetime, detectability at low concentration, and relatively long wavelength of excitation (300 nanometers). In protein kinase systems it is a highly acceptable substitute for adenosine 3',5'-monophosphate.     

Nerve growth factor: relationship to the cyclic AMP system of sensory ganglia

Nerve growth factor and N(6),O(2)' dibutyryl adenosine 3',5'-monophosphate both stimulate neurite elongation by explanted ganglia. However, the addition of nerve growth factor does not lead to increased amounts of adenosine 3',5'-monophosphate in intact ganglia, nor does it stimulate adenylate cyclase activity in broken ganglia cells.     

与Mi相关的抗蚜基因的引物设计

通过NCBI等生物信息数据库搜索出与此抗蚜相关的Mi-1.1、Mi-1.2的基因组DNA序列[(Mi-1.1(CS025317 3768 bp,DNA和Mi-1.2(CS025319,3774bp,DNA)],采用Primer Premier生物信息学软件设计出Mi-1.1、Mi-1.2基因组DNA的PCR扩增引物,采用Oligo对引物进行分析,并得到:Mi-1.1的上下游引物分别是5'-AAATACTGTGGTTGCGTGAA-3'(Seq No:3347)和3'-GGGTGCTCGAAGTCTAGG-5'(Seq No:3736);Mi-1.2的上下游引物分别是5'-TAAAGTTGCGAGTGCTGT-3'(Seq No:2996)和3'-TGTTAGTAGGTCCCTCTT-5'(SeqNo:3462)。为抗蚜育种研究和PCR扩增提供条件。     

Divergent biological effects of adenosine and dibutyryl adenosine 3',5'-monophosphate on the isolated fat cell

Adenosine 3',5'-monophosphate stimulated production of carbon dioxide and lipid from glucose, whereas its dibutyryl derivative inhibited this conversion. Addition of the dibutyryl derivative to the isolated fat cell further stimulated lipolysis induced by adrenocorticotropic hormone, whereas addition of adenosine 3',5'-monophosphate inhibited this lipolysis. Hence, measured by these two parameters, the biologic properties of adenosine 3',5'-monophosphate and its dibutyryl derivative are distinctly different.     

An RNA processing activity that debranches RNA lariats

The excised introns of pre-messenger RNA's (pre-mRNA's) and intron-containing splicing intermediates are in a lariat configuration in which the 5' end of the intron is covalently joined by a 2',5'-phosphodiester bond to a specific adenosine residue near the 3' end of the intron. A 2',5'-phosphodiesterase activity in HeLa cell extracts has been detected that debranches RNA lariats, converting them to linear RNA molecules by specific cleavage of the 2',5'-phosphodiester bond. This lariat debranching activity is distinct from previously reported 2',5'-phosphodiesterases with regard to its biochemical and substrate requirements as well as its stringent cleavage specificity. The debranching activity is observed only if the RNA lariats generated during in vitro processing are deproteinized and added back to the extract. These results suggest that during the normal in vitro splicing reaction the 2',5'-phosphodiester bond of RNA lariats is protected from cleavage by the lariat debranching activity.     

Vasoactive intestinal peptide alters membrane potential and cyclic nucleotide levels in retinal horizontal cells

Vasoactive intestinal peptide stimulated the synthesis of adenosine 3',5'-monophosphate in fractions of isolated carp horizontal cells. When applied extracellularly to isolated and cultured horizontal cells, the peptide also induced a slow depolarization (30 to 40 millivolts) accompanied by a decrease in membrane resistance. However, analogs of adenosine 3',5'-monophosphate applied extracellularly or intracellularly, and forscolin applied extracellularly, had no effect on the membrane potential of cultured horizontal cells, indicating that the induced depolarization was not related to the accumulation of adenosine 3',5'-monophosphate in these cells.     

Dopamine-sensitive adenyl cyclase: possible role in synaptic transmission

An adenyl cyclase activated by low concentrations of dopamine has been found in the mammalian superior cervical sympathetic ganglion. The existence of this enzyme may account for the increased amount of adenosine 3',5' monophosphate associated with synaptic activity in the ganglion. The results suggest that the physiological effects of dopamine in the ganglion, and possibly elsewhere in the nervous system, may be mediated by stimulating the synthesis of adenosine 3',5'-monophosphate.