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961.
P E Berg J K Yu Z Popovic D Schumperli H Johansen M Rosenberg W F Anderson 《Molecular and cellular biology》1983,3(7):1246-1254
A series of plasmids was constructed to study the effect of two enhancers, the simian virus 40 72-base-pair repeat and the Harvey sarcoma virus 73-base-pair repeat, on the mouse beta maj-globin promoter. These plasmids contain the mouse beta maj-globin promoter linked to the Escherichia coli galK gene, thus allowing galactokinase enzyme activity to be used as a measure of promoter function. In CV-1 (primate) cells, it was found that an enhancer is required for optimal promoter activity and that the simian virus 40 (primate) enhancer increases galactokinase fourfold more than the Harvey sarcoma virus (mouse) enhancer. In L (mouse) cells, however, the Harvey sarcoma virus enhancer is 1.3-fold stronger than the simian virus 40 enhancer. These data support the hypothesis that enhancer activity can be species specific. Furthermore, when both enhancers are present on the same plasmid, their effect is additive on the beta-globin promoter whether the plasmid is in CV-1 cells or L cells. 相似文献
962.
A simple procedure for the isolation and preparative gel electrophoresis of snRNA and scRNA is described. These small RNA species were used to select DNA sequences from a human genomic library which are able to protect hybridized snRNA or scRNA against T1-ribonuclease attack. The snRNA clones obtained contain only sequences for one snRNA species and only one copy of the respective gene. In contrast, more than one 7S RNA gene is present within the scRNA clones. 相似文献
963.
Immunohistochemistry of tonin in rat submandibular gland during development, lactation and secretion 总被引:1,自引:0,他引:1
Tonin is a serine protease found in high concentrations in the submandibular gland (SMG) of the adult rat where it has been localized by immunohistochemistry in the granular ducts. The present study examined the development of tonin in the SMG, the effect of lactation and of stimulation of tonin release, using the peroxidase-antiperoxidase technique and antitonin. Tonin-like immunoreactivity first appeared in the primitive striated duct of the SMG on day 19 foetal and increased in intensity as the ducts developed into granular ducts. Reaction product in granules was seen on day 17 postpartum. Its localization within granules was established by immunochemistry of Sepharose beads to which had been coupled the contents of granules isolated from adult rats. The granular ducts of female rats, which are less developed than in the male, showed a marked increase in tonin-immunoreactivity during lactation. Stimulation of tonin secretion by isoprenaline caused massive discharge of tonin-like immunoreactivity into the lumen of the granular ducts during in vitro incubation. However, within one hour complete regranulation was apparent. The secretion was prevented by propranolol. The results indicate that tonin or a tonin-like substance appears in the rat submandibular gland late in gestation in ducts that presumably develop into granular ducts where it is found in abundance in granules in the adult, that the amount in females is increased during lactation, and that most of the granules are discharged during stimulation, only to be rapidly replaced. 相似文献
964.
T. E. Thompson 《Journal of Zoology》1972,166(3):391-409
Collections of nudibranch gastropods made in 1968 and 1969 are described. All the 11 eastern Australian species of Casella, Hypselodoris and Chromodoris obtained are fully illustrated by line diagrams, photographs and water-colours. Two species new for Australia are described, and nine others are re-described. A list of the chromodoridiform species reliably recorded from Australian waters concludes the paper. 相似文献
965.
Neil S. Painter Anthony Z. Almeida Kenneth W. Colebourne 《BMJ (Clinical research ed.)》1972,2(5806):137
Seventy patients with diverticular disease of the colon were treated with a high-residue, low-sugar diet including unprocessed bran. Follow-up for an average of 22 months showed marked relief of symptoms in 62 patients. Bowel habit was restored towards normal and abdominal discomfort relieved. Only seven patients were unable to give up the use of laxatives. Eight patients did not tolerate the bran diet, and one of these needed surgical treatment. None of the 62 patients who took the diet needed surgery. 相似文献
966.
N. Z. El-Shazly 《BioControl》1972,17(2):203-209
Zusammenfassung Die F?higkeit vonNeomyzus circumflexus (Buck.), Larven vonAphelinus asychis durch Blutzellen abzukapseln, ist nach drei Generationen auf einem synthetischen N?hrmedium ohne Phenylalanin und Tyrosin
stark reduziert. Nach Umsetzen auf ein vollst?ndiges N?hrmedium erreichen H?ufigkeit und Intensit?t der Abwehrreaktionen erst
in der dritten nachfolgenden Generation wieder ihr ursprünglisches Ausmass.
Das Abwehrverm?gen der Jungl?use sinkt mit zunehmendem Alter des Muttertieres zum Zeitpunkt der Geburt. Ihr Gewicht wird gleichzeitig
etwas reduziert.
Summary The aphid,Neomyzus circumflexus (Buck.) is able to encapsulate the newly hatched larvae of its endoparasite.Aphelinus asychis Walker, with blood cells. This haemocytic reaction was strongly reduced when the aphids were reared for three successive generations on an artificial diet lacking phenylalanine and tyrosine. But when these aphids were fed a full diet (original diet containing vitamins, trace elements, sucrose and 22 amino acids) the reaction increased and reached its original intensity in the third generation. With increasing age of the mother at parturition, the ability of the young aphid to encapsulate parasitic larvae decreased and its weight was also reduced slightly.相似文献
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