输液瓶的吸附作用对胰岛素输注过程中浓度变化的影响

为了解胰岛素注射液在输液过程中的浓度变化情况,指导临床合理操作,模拟了临床胰岛素配液以及输注操作过程,实验分为玻璃瓶组和塑料瓶组,各组又按操作的不同分为输液组和吸附组.采用紫外分光光度法测定胰岛素浓度.输液组流速为50滴/min,每输注50 mL液体取样测定胰岛素浓度.吸附组按溶媒不同分为氯化钠组、50 g/L葡萄糖组和100 g/L葡萄糖组,每隔10 min轻轻振摇1次,并取液测定浓度.结果表明,不同材质和装有不同溶媒的输液瓶对胰岛素的吸附趋势类似,但塑料瓶对胰岛素的吸附量大于玻璃瓶,装有氯化钠的输液瓶大于葡萄糖输液瓶,100 g/L葡萄糖输液瓶大于50 g/L葡萄糖输液瓶.因此,在胰岛素输液过程中,应考虑到输液瓶对胰岛素的吸附导致的药量损失.     

Is sequence conservation in interferons due to selection for functional proteins?

The human alpha-interferon (IFN-alpha) gene family consists of at least 14 potentially functional non-allelic members; the amino acid sequences they encode differ from each other by up to approximately 20% of their residues. Human IFN-beta, which is encoded by a single gene, is distantly related to the IFN-alpha family; it differs in 67% of its residues from IFN-alpha 2. There is considerable evidence that IFN-alpha and -beta compete for the same receptors on their target cells. Comparison of 14 non-allelic human IFN-alpha sequences and the IFN-beta sequence has revealed that 37 of 166 residues are completely conserved and that several of these are arranged in clusters, for example at positions 29-33, 47-50 and 136-150. It is commonly held that evolutionary conservation of amino acids indicates that the residues in question are essential for function. To test this hypothesis in the case of IFNs, we have introduced single site-directed point mutations into the strictly conserved codons 48 and 49 of the IFN-alpha 2 gene which form part of the longest uninterrupted cluster (position 47-50). We report here that the mutant proteins, containing Tyr, Ser and Cys instead of Phe48, or His instead of Gln49, have biological activities indistinguishable from those of wild-type IFN-alpha. In addition, when Glu62, a residue conserved in all known alpha and beta IFNs of man, mouse and cattle, was replaced by Lys, antiviral activity remained unchanged.     

Endotoxin-induced acceleration of ovum transport in rabbits

Summary Salmonella enteritidis-Boivin endotoxin (1–20 g/kg) induced accelerated oviductal ovum transport in rabbits in a dose-related manner. Indomethacin prevented this effect. Levels of prostaglandin E and F in uterine vein blood increased following endotoxin injection.Deceased 6 December, 1977.Thanks are due to Elizabeth Menchaca, Larry Coons and Lenore Weinberg for technical assistance, and to Merck, Sharp, and Dohme for the gift of indomethacin. This work was supported by Rockefeller Foundation, NIH (HD-09339) and WHO (S76119). G. V. is a Rockefeller Foundation Postdoctoral Fellow in Reproductive Biology. Reprint requests to M. J. K. Harper.     

直线永磁振动电机的磁场与静推力特性分析

主要介绍了一种直线永磁振动电机的结构及其工作原理，并用有限元软件对其在不同位置时的磁场进行了分析，同时搭建实验台做了实际的测试，给出了误差及出现误差的原因。该电机结构简单，可靠性高，寿命长，易维护，并且控制电路简单，运行平稳，适用于小功率电磁间的开关系统中。     

G0 is a major growth cone protein subject to regulation by GAP-43

G0, a GTP-binding protein that transduces information from transmembrane receptors, has been found to be a major component of the neuronal growth cone membrane. GAP-43, an intracellular growth cone protein closely associated with neuronal growth, stimulates GTP-gamma-S binding to G0. It does so through an amino-terminal domain homologous to G-linked transmembrane receptors. Thus, G0 in the growth cone may be regulated by intracellular as well as extracellular signals.     

Time course study of the changes in blood glutathione induced by acute ethanol intoxication in the rat

Acute ethanol treatment of rats (5 g/kg) has a biphasic effect on the glutathione content of the erythrocyte. After 3 h of intoxication there is a diminution in total GSH equivalents, followed by a recovery to basal values 6 h after treatment. The decrease of total GSH equivalents is mainly due to a diminution of the oxidized form of the tripeptide. Concomitantly a marked increase in the plasma level of glutathione was found at 3 h, followed by a diminution to values obtained at time zero.     

Dominant mutations in ROR2, encoding an orphan receptor tyrosine kinase, cause brachydactyly type B

Inherited limb malformations provide a valuable resource for the identification of genes involved in limb development. Brachydactyly type B (BDB), an autosomal dominant disorder, is the most severe of the brachydactylies and characterized by terminal deficiency of the fingers and toes. In the typical form of BDB, the thumbs and big toes are spared, sometimes with broadening or partial duplication. The BDB1 locus was previously mapped to chromosome 9q22 within an interval of 7.5 cM (refs 9,10). Here we describe mutations in ROR2, which encodes the orphan receptor tyrosine kinase ROR2 (ref. 11), in three unrelated families with BDB1. We identified distinct heterozygous mutations (2 nonsense, 1 frameshift) within a 7-amino-acid segment of the 943-amino-acid protein, all of which predict truncation of the intracellular portion of the protein immediately after the tyrosine kinase domain. The localized nature of these mutations suggests that they confer a specific gain of function. We obtained further evidence for this by demonstrating that two patients heterozygous for 9q22 deletions including ROR2 do not exhibit BDB. Expression of the mouse mouse orthologue, Ror2, early in limb development indicates that BDB arises as a primary defect of skeletal patterning.