枳■子黄酮类成分研究

从北枳（ＨｏｖｅｎｉａｄｕｌｃｉｓＴｈｕｎｂ）种子中首次分离并鉴定了４个黄酮类化合物，即双氢山奈酚（ｄｉｈｙｄｒｏｋａｅｍｐｆｅｒｏｌＩ）、槲皮素（ｑｕｅｒｃｅｔｉｎＩＩ）、（＋）３，３′，５′，５，７五羟基双氢黄酮［（＋）３，３′，５′，５，７ｐｅｎｔａｈｙｄｒｏｆｌａｖａｎｏｎｅＩＩ］和（＋）双氢杨梅黄素［（＋）ｄｉｈｙｄｒｏｍｙｒｉｃｅｔｉｎＩＶ］。其中ＩＩ为新化合物，Ｉ和ＩＶ为首次从该属植物中分到。     

鼓槌石斛化学成分的研究

自中药鼓槌石斛(Dendrobium chrysotoxum Lindl.)茎中分离到5个化合物,经光谱(UV,IR,MS,¹HNMR,DIFNOE和¹³CNMR)分析,分别鉴定为β-谷甾醇(I)、鼓槌菲(chrysotoxene,II)、毛兰素(erianin,III)、毛兰菲(confusarin,IV)和鼓槌联苄(chrysotobibenzyl,V)。II是新化合物,V是新天然产物。     

Approach to seizures in the neonatal period: a European perspective

In the neonatal period, seizures rank among the most common neurological symptoms, often indicating an underlying serious neurological condition. It is remarkable that although new tools have been incorporated into the diagnosis of neonatal seizures, there is no consensus about the therapeutic approach among different doctors and institutions. Hence, although phenobarbital is still considered the initial drug of choice, the protocols reported in the literature show a great variability in the approach to treatment of refractory seizures. We used a questionnaire to gain information regarding the treatment of seizures in the neonatal period in different European institutions. Conclusion: We conclude that phenobarbital is still the initial drug of choice followed by benzodiazepines, except in preterm infants with a birth weight below 1800 g. In refractory seizures, the use of continuous lidocaine infusion is most common. Of note, clinical studies with newer drugs have been mostly performed in the United States but not in Europe.     

Erythropoietin structure-function relationships: high degree of sequence homology among mammals

To investigate structure-function relationships of erythropoietin (Epo), we have obtained cDNA sequences that encode the mature Epo protein of a variety of mammals. A first set of primers, corresponding to conserved nucleotide sequences between mouse and human DNAs, allowed us to amplify by polymerase chain reaction (PCR) intron 1/exon 2 fragments from genomic DNA of the hamster, cat, lion, dog, horse, sheep, dolphin, and pig. Sequencing of these fragments permitted the design of a second generation of species-specific primers. RNA was prepared from anemic kidneys and reverse-transcribed. Using our battery of species-specific 5' primers, we were able to successfully PCR- amplify Epo cDNA from Rhesus monkey, rat, sheep, dog, cat, and pig. Deduced amino acid sequences of mature Epo proteins from these animals, in combination with known sequences for human, Cynomolgus monkey, and mouse, showed a high degree of homology, which explains the biologic and immunological cross-reactivity that has been observed in a number of species. Human Epo is 91% identical to monkey Epo, 85% to cat and dog Epo, and 80% to 82% to pig, sheep, mouse, and rat Epos. There was full conservation of (1) the disulfide bridge linking the NH2 and COOH termini; (2) N-glycosylation sites; and (3) predicted amphipathic alpha- helices. In contrast, the short disulfide bridge (C29/C33 in humans) is not invariant. Cys33 was replaced by a Pro in rodents. Most of the amino acid replacements were conservative. The C-terminal part of the loop between the C and D helices showed the most variation, with several amino acid substitutions, deletions, and/or insertions. Calculations of maximum parsimony for intron 1/exon 2 sequences as well as coding sequences enabled the construction of cladograms that are in good agreement with known phylogenetic relationships.     

鼓槌石斛中一新的联苄类化合物——鼓槌石斛素

从兰科鼓槌石斛(Dendrobium chrysotoxum)中分得一新的联苄类化合物,经光谱分析(UV,IR,MS,¹HNMR,¹³CNMR和DIFNOE),其结构确定为4-羟基-3,5,3',4'-四甲氧基联苄,命名为鼓槌石斛素。关键词鼓槌石斛;鼓槌石斛素;联苄类化合物。