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11.
B. C. Broughton A. F. Thompson S. A. Harcourt W. Vermeulen J. H. J. Hoeijmakers E. Botta M. Stefanini M. D. King C. A. Weber J. Cole C. F. Arlett A. R. Lehmann 《American journal of human genetics》1995,56(1):167-174
Xeroderma pigmentosum (XP) and Cockayne syndrome (CS) are quite distinct genetic disorders that are associated with defects in excision repair of UV-induced DNA damage. A few patients have been described previously with the clinical features of both disorders. In this paper we describe an individual in this category who has unusual cellular responses to UV light. We show that his cultured fibroblasts and lymphocytes are extremely sensitive to irradiation with UV-C, despite a level of nucleotide excision repair that is 30%–40% that of normal cells. The deficiency is assigned to the XP-D complementation group, and we have identified two causative mutations in the XPD gene: a gly→arg change at amino acid 675 in the allele inherited from the patient's mother and a −1 frameshift at amino acid 669 in the allele inherited from his father. These mutations are in the C-terminal 20% of the 760-amino-acid XPD protein, in a region where we have recently identified several mutations in patients with trichothiodystrophy. 相似文献
12.
A.K. Banerjee B.J. Broughton T.S. Burton M.P.L. Caton A.J. Christmas E.C.J. Coffee K. Crowshaw M.A. Heazell K.A.J. Stuttle G.L. Watkins 《Prostaglandins & other lipid mediators》1978,16(4):541-554
The synthesis and gastrointestinal pharmacology of some 11-deoxyprostaglandin E1 analogues are described with results analysed for selectivity from side effects. 11-Deoxygenation reduced potency relative to PGE2 but, as has been reported for natural PGs, 15- or 16-methyl analogues were more potent than the unsubstituted parent compound in the order 16-methyl > 15-methyl > 16, 16-dimethyl. The results suggest that a complex interaction between C-15 and C-16 in methyl analogues affects their profile of activity, but that none of the modifications studied conferred a substantial potency or selectivity advantage over PGE2. 相似文献
13.
Axenic cultures of bacteroid-containing protoplasts were isolated from root nodules of Vigna unguiculata L. Walp. Dimensions of the protoplasts were 35 to 135 m long x 35 to 95 m wide. Yields were about 30 to 50 mg dry weight per gram fresh weight of nodules. About 5x108 protoplasts packed into 1 ml of basal medium under the influence of gravity. When incubated in hypertonic, nitrogen-free media, freshly isolated protoplasts began to reduce acetylene to ethylene after a lag period of 24 to 48 h. Various additions to the basal medium showed that the system possessed functional glycolytic and tricarboxylic acid pathways. Endogenous application of various intermediary metabolites stimulated both acetylene reduction and respiration, though not often equally. As acetylene reduction, but not respiration, was inhibitable by both asparagine and glutamine, the system appears suitable for the study of mechanisms controlling symbiotic nitrogen fixation.Abbreviations BSA
bovine serum albumine
- HEPES
N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid
- PEP
phospho(enol)pyruvate
- UMKL 76
University of Malaga, Kuala Lumpur, Rhizobium, No. 76
- TCAC
tricarboxylic acid cycle 相似文献
14.
Two methods (whole-plant growth analysis and gas exchange) were used to measure the response of Psophocarpus tetragonolobus (L.) DC cultivar UPS 99 to the environment. This plant had an optimal temperature for root growth of 25°C, its rate of acetylene reduction (when inoculated with Rhizobium, strain RRIM 56) was maximal at 30°C and it required an atmospheric temperature of about 35°C for optimal shoot growth. Maximum water-use efficiency was ca. 33 mg CO2·g H2O-1. The rate of photosynthesis reached a plateau at 900 vpm CO2-this condition also gave the lowest rate of transpiration. Under normal conditions, the light compensation point was at 1.7 klx, while that for CO2 was 60 vpm. Photorespiration diminished gross photosynthesis of P. tetragonolobus by forty percent. Water stress (as measured by sensitivity to slightly increased CO2 levels) caused rapid closure of stomata, and the response was remembered for up to five days.
Zusammenfassung Mit Hilfe von zwei Methoden (Wachstumsanalysen ganzer Pflanzen und Gaswechselmessungen) wurde die Reaktion von Psophocarpus tetragonolobus (L.) DC der Sorte UPS 99 auf Umwelteinflüsse ermittelt. 25°C war die optimale Temperatur für das Wurzelwachstum. Die Acetylenreduktionsrate (die Pflanzen waren geimpft worden mit Rhizobium RRIM 56) war am höchsten bei 30°C. 35°C waren notwendig für maximales Sproßwachstum. Der günstigste Wasserausnutzungskoeffizient lag bei ungefähr 33 (mg CO2·g H2O-1). Die Photosyntheseraten wurden durch Erhöhung der CO2-Konzentration gesteigert. Bei Konzentrationen über 900 vpm CO2 konnte allerdings keine weitere Steigerung mehr festgestellt werden. Bei 900 vpm CO2 waren die Transpirationsraten am niedrigsten. Unter normalen Bedingungen stellte sich der Lichtkompensationspunkt bei 1,7 klx ein. Der CO2-Kompensationspunkt lag bei 60 vpm CO2. Die Photorespiration verminderte die Photosynthese von P. tetragonolobus um 40%. Wasserstreß vergrößerte die Empfindlichkeit der Stomata gegenüber etwas erhöhten CO2-Konzentrationen (die Stomata schließen). Diese Empfindlichkeit war bis zu 5 Tagen nach der Streßbehandlung noch meßbar.相似文献
15.
P.M.Shaughn O'Brien G.Marcus Filshie Fiona Broughton Pipkin 《Prostaglandins & other lipid mediators》1977,13(1):171-181
The rise in arterial blood pressure in response to angiotensin II was studied in the last third of pregnancy in rabbits. The response was compared with that of pregnant rabbits during infusion of prostaglandin E2 and F2α. Prostaglandin E2 significantly diminished the rise in diastolic pressure in response to angiotensin II. Prostaglandin F2α did not alter the response. Intravenous indomethacin elevated the blood pressure and caused an absolute increase in the pressor response. It did not mediate a change in the percentage rise in blood pressure in response to angiotensin II. 相似文献
16.
The carotenoid pigments of a Rhizobium strain isolated from Lotononis bainesii were found to be diglucosyl-4,4-diapocarotene-4,4-dioate and glucosyl-4,4-diapocarotene-4-oate-4-oic acid.5th publication in the series Carotenoids of Rhizobia [4th publication: Helv. chim. Acta 62: 2551–2557 (1979)] 相似文献
17.
First year roach from a Stillwater habitat were maintained in an'artificial stream for periods of up to 40 days and samples of the lateral musculature were subjected to histological examination. It was found that there was a highly significant increase in the percentage of red muscle present in the hindermost regions of the fish confined for 30 days or more in the stream. In subsequent exercise tests, it was shown that the FV50 was higher for fish conditioned for 40 days, but it was considered unlikely that this increase in swimming ability was as a direct result of changes in muscle composition. 相似文献
18.
Maternal and fetal plasma concentrations of free fatty acids, triacylglycerols and phospholipids and the profile of their fatty acids were measured in three catheterized and unanaesthetized sheep. Fetal concentrations of all three lipid fractions were low and did not correlate with maternal concentrations. There were no measurable umbilical venous-arterial differences. Linoleic acid concentrations were low in both mother and fetus. The fatty acid composition of fetal adipose tissue, liver, lung and cerebellum of five animals was analysed. Again linoleic acid levels were very low, but phospholipids contained 2-8% arachidonic acid. [14C] linoleic acid and [3H] palmitic acid were infused intravenously into three ewes. Only trace amounts of labelled fatty acids were found in fetal plasma and these were confined to the free fatty acids. 14C-label was incorporated into fetal tissue lipids, but most of this probably was due to fetal lipid synthesis from [14C] acetate or other water-soluble products of maternal [14C] linoleic acid catabolism. It is concluded that only trace amounts of fatty acids cross the sheep placenta. They are derived mainly from the maternal plasma free fatty acids and might just be sufficient to be the source of the small amounts of essential fatty acids found in the lamb fetus, but are insignificant in terms of energy supply or lipid storage. 相似文献
19.
Dental anomalies were observed in 43 of 1,226 barren-ground caribou (Rangifer tarandus groenlandicus) taken between 1966 and 1968. In five of these 43 animals, the mandibles had deformities which radiography showed to be the result of dental abscesses in four cases and probably of a trauma in the other. The absence of actinomycotic lesions of the jaw bones of these 1,226 animals, and of more than 500 examined previously, indicates that "lumpy jaw" is rare in barren-ground caribou. The authors suggest the use of radiography to determine the nature of bone growth on skeletal remains, in the absence of soft tissues for examination for Actinomyces, either microscopically or by cultural methods. 相似文献
20.