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21.
Summary A large family is reported in which mental retardation associated with the fragile site at Xq28 was found. Three normal males seemed to have transmitted the trait through their daughters to affected grandchildren.A total of 19 family members were investigated cytogenetically. Mentally retarded males showed macroorchidism and the fragile X. Three mentally retarded females were found, with the fragile X in a high percentage of cells; in contrast, the obligate carriers showed no or only few cells with the fragile X. 相似文献
22.
Induction of cytochrome P-450IA1, IA2, IIB1, IIB2 and IIE1 by broccoli in rat liver and colon 总被引:2,自引:0,他引:2
Ingestion of broccoli or other cruciferous vegetables inhibits the induction of cancer by chemicals and modifies some cytochrome P-450 enzyme activities. The effect of dietary broccoli on the levels of P450IA and IIB mRNA and proteins in rat liver and colon has been studied. Rats were fed a ten percent broccoli diet for 7 days. The expression of the cytochrome P-450 forms was altered to a different extent in the liver and colon. The level of total P450IA mRNA in the liver was increased by the broccoli together with the P450IA1 and IA2 proteins. Colonic P450IA1 mRNA and protein were induced by the broccoli diet, whereas only P450IA2 protein and not mRNA was detectable in colon, but the protein level was unaffected by the broccoli diet. Liver P450IIB and IIE1 proteins were increased by the broccoli diet, whereas the level of P450IIB mRNAs was not affected. In contrast, the P450IIB mRNA levels were reduced but the protein levels were increased in colon and we suggest that a feedback mechanism caused the decrease of the P450IIB mRNAs levels. Because the ratio between activation and deactivation may be an important risk determinant, we conclude that the protective effect of the broccoli diet on chemically induced tumors in rodents may be caused by the broccoli-induced changes in P450IA and IIB associated enzyme activities. 相似文献
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24.
Isolation and characterization of lambda phages carrying the basic replicon of the resistance plasmid R1 总被引:2,自引:0,他引:2
Summary Specialized transducing lambda phages, oriR1, harboring DNA from the resistance plasmid R1drd-19 and its copy mutant pKN103 were isolated. From measurements of CCC-DNA content it is concluded that upon infection the phages can establish themselves as self-replicating plasmids in recA hosts lysogenic for lambda. It is thought that this bypassing of lambda immunity is due to the presence of the R1 origin of replication. The plasmids are sensitive to the incompatibility expressed by plasmid R1. This has been shown mainly by transduction of oriR1 into recipients containing R1 plasmids or plasmid pBR322 carrying the basic replicon. We were able to demonstrate that a copy mutant of plasmid R1 was insensitive to copA
+, but sensitive to the conserted action of Pst1 fragments F1 and F2. This mutant was previously assumed to be of the dominant type. Physical mapping of the oriR1 derivatives verified that they carry the basic replicon of plasmid R1. The plasmids are not stably maintained, but are lost in a frequency of 1%–2% per cell generation, which is consistent with their lack of the R1par region. 相似文献
25.
Synthesis of phosphatidylglycerol from CDPdiacylglycerol and glycerol 3-phosphate by membranous subcellular fractions of rat lung and liver was optimal when assayed in the presence of bovine serum albumin and Triton X-100. Specific activities of glycerolphosphate phosphatidyltransferase in all membranous subcellular fractions of lung were several times higher than the corresponding fractions from liver. Distribution of this enzyme in subcellular fractions of lung or liver closely parallel the activity of the mitochondrial enzymes monoamine oxidase and succinate cytochrome c reductase. The phosphatidylglycerol-synthesizing activity in microsomes of both lung and liver was a minor fraction of total tissue activity and could be interpreted as due either to contamination with outer mitochondrial membrane or to a small amount of activity innate to microsomes. These results suggest that phosphatidylglycerol, which is believed to be a component of pulmonary surfactant, is synthesized by lung at a rapid rate relative to liver and that the subcellular distribution of its synthesis is similar in both tissues, with mitochondria as the major site. 相似文献
26.
Hanne Kaas 《Nordic Journal of Botany》1987,7(6):735-749
The blue-green algal flora in the higher salt marsh areas (above average high tide level) at Rejsby in the Danish Wadden Sea area has been investigated regularly throughout a one-year period. Twenty nine pigmented and two colourless taxa were recorded, and their morphology described in detail. The blue-green algae were particularly well developed in the the grazed Puccinellia marsh, at other sites the occurrence was scattered. In winter and spring few algae were seen. Mats appeared in June and then persisted for shorter or longer periods, in some areas throughout the rest of the year. On the basis of frequency analyses, thirteen assemblages characterized by the dominating species were recognized. Factors affecting the spatial and temporal distribution are discussed. The assemblages are compared to the algal communities described by Polderman. 相似文献
27.
Gabriella Galatà Andrés C. García-Montero Thomas Kristensen Ahmed A.Z. Dawoud Javier I. Muñoz-González Manja Meggendorfer Paola Guglielmelli Yvette Hoade Ivan Alvarez-Twose Christian Gieger Konstantin Strauch Luigi Ferrucci Toshiko Tanaka Stefania Bandinelli Theresia M. Schnurr Torsten Haferlach Sigurd Broesby-Olsen Hanne Vestergaard William J. Tapper 《American journal of human genetics》2021,108(2):284-294
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29.
Caroline P. Baron Lis Berner Leif H. Skibsted Hanne H.F. Refsgaard 《Free radical research》2013,47(7):777-785
Protection against protein oxidation by lipophilic and hydrophilic antioxidants in model systems using bovine serum albumin (BSA) in solution alone, or in an emulsion with linolenic acid methyl ester (LnMe) was found to be strongly dependent on the oxidation initiator. Tocopherol, Trolox, or the carotenoids astaxanthin and canthaxanthin were incubated with BSA or BSA/LnMe and oxidation was initiated either with the water-soluble azo-initiator 2,2′ azo-bis-(2-amidinopropane) hydrochloride (AAPH), or FeCl3 and ascorbate, or the Fenton system using FeCl2/EDTA/H2O2, or with the singlet oxygen generating species anthracene-9,10-dipropionic acid disodium 1,4 endoperoxide (NDPO2).The results show that all the antioxidants tested were inefficient in the system with FeCl3/ascorbate. However, with the other initiating agents, the hydrophilic antioxidant, Trolox, was the most effective in preventing both protein and lipid oxidation. In contrast the lipophilic antioxidants were ineffective in preventing oxidation of BSA in aqueous solution, but did show some moderate antioxidative activity on protein and lipid in the BSA/LnMe system. Using the singlet oxygen generating system it was also demonstrated that Trolox always provided better protection of the protein than tocopherol and the carotenoids in both the BSA and the BSA/LnMe systems. In conclusion, prevention of protein oxidation using a water-soluble antioxidant has a protective effect on the lipid fraction and this approach deserves further attention in complex biological systems. 相似文献
30.
Jens‐Peter David Martin N. Andersen Søren‐Peter Olesen Hanne B. Rasmussen Nicole Schmitt 《Traffic (Copenhagen, Denmark)》2013,14(4):399-411
The voltage‐gated potassium channel KV7.1 is regulated by non‐pore forming regulatory KCNE β‐subunits. Together with KCNE1, it forms the slowly activating delayed rectifier potassium current IKs. However, where the subunits assemble and which of the subunits determines localization of the IKs‐complex has not been unequivocally resolved yet. We employed trafficking‐deficient KV7.1 and KCNE1 mutants to investigate IKs trafficking using the polarized Madin‐Darby Canine Kidney cell line. We find that the assembly happens early in the secretory pathway but provide three lines of evidence that it takes place in a post‐endoplasmic reticulum compartment. We demonstrate that KV7.1 targets the IKs‐complex to the basolateral membrane, but that KCNE1 can redirect the complex to the apical membrane upon mutation of critical KV7.1 basolateral targeting signals. Our data provide a possible explanation to the fact that KV7.1 can be localized apically or basolaterally in different epithelial tissues and offer a solution to divergent literature results regarding the effect of KCNE subunits on the subcellular localization of KV7.1/KCNE complexes . 相似文献