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1.
2.
The presence of trace amounts of metal ions in nonviral vector formulations can significantly affect the stability of lipid/DNA complexes (lipoplexes) during acute freeze-drying. The goal of the present study was to evaluate the generation of reactive oxygen species (ROS) in dried formulations of lipoplexes and in their individual components (lipid or naked DNA). The experiments were conducted in the presence or absence of a transition metal (Fe2+). Lipoplexes and their individual components were formulated in trehalose and subjected to lyophilization and stored for a period of up to 2 months at + 60 °C. Physico-chemical characteristics and biological activity were evaluated at different time intervals. Generation of ROS during storage was determined by adding a fluorescence probe to the formulations prior to freeze-drying. We also monitored the formation of thiobarbituric reactive substances (TBARS). Our results show that ROS and TBARS form during storage in the dried state. Our findings also suggest that degradation is more rapid in the presence of lipid, even in the absence of metal. We also showed that dried naked DNA formulations are more stable without the lipid component. Effective strategies are then needed to minimize the formation and accumulation of oxidative damage of lipoplexes during storage. 相似文献
3.
高碳水化合物日粮对翘嘴红鲌生长、GK及GK mRNA表达的影响 总被引:6,自引:0,他引:6
探讨不同碳水化合物(CHO)水平对翘嘴红NFDA5生长、葡萄糖激酶(GK)及GK基因表达的影响.选用540尾(40.73±0.44)g翘嘴红鲌,随机分成为高CHO组、中CHO组、无CHO组,每组设三个重复,饲养8周,测定鱼体生长、血液指标、GK活性及GK mRNA水平等指标.结果显示,随着CHO添加量的增加,鱼体特定生长率与死亡率呈下降趋势,饵料系数刚好相反.摄食后,血糖先上升后趋于平缓,其中高CHO组相对高,无糖组低;血浆甘油三酯先上升后下降再上升又下降,其中高CHO组相对高,中CHO组最低;无CHO组血浆胆固醇、中CHO组HK活性、高CHO组GDH相对较低,其他各组在投喂后都呈先上升后下降.GK活性总体呈上升趋势,各组在禁食时,检测不到GK活性,饲料CHO含量越高,GK活性也越高,但是GK mRNA的水平与CHO含量并不呈线性关系.血糖、GK活性与GK mRNA的水平之间有一定的相关性,摄食高CHO饲料可诱导GK酶活性及基因的表达,造成持续高血糖,这可能不利于生长. 相似文献
4.
Monocotyledons of 104 species in 52 families were divided into two groups depending on the UV fluorescence behaviour of their cell walls. The unlignified cell walls of the first group, fluoresced blue, which changed to green with increased intensity after treatment with NH3 due to the presence of bound ferulic acid. The isolated cell walls of members of the first group were shown to contain bound ferulic, p-coumaric and diferulic acids. These acids were absent from cell walls of the second group. The first group contained families of the Commelinidae of Cronquist, the Palmae (part of the Arecidae), and the Philydraceae, Pontederiaceae, and Haemodoraceae (all part of Liliidae). The other families of the latter two subclasses and those of the Alismatidae belonged to the second group. 相似文献
5.
As the first part of a comprehensive study of the hormonal control of lateral root initiation and development, the effect of surgical treatments such as removal of the root tip, one or more cotyledons, the young epicotyl, or combination of these treatments, on the induction and emergence of lateral roots on the primary root of pea seedlings has been examined. Results show that removal of the root tip leads to a rapid but transitory increase in the number of lateral primordia, the largest number arising in the most apical segment of decapitated roots suggesting the accumulation of acropetally moving promoter substances in this region. The cotyledons appear to be the main source of promoter substances for both the induction and emergence of lateral roots, although one or more promoters also appear to be produced in the epicotyl. The data further indicate that the root tip is possibly the source of a substance which moves basipetally and interacts with acropetally moving promoters to regulate the zone for lateral primordia initiation; the root tip also appears to be the source of a powerful inhibitor of lateral root emergence. 相似文献
6.
Leucine aminopeptidase in sheep serum was studied by starch gel electrophoresis. Two phenotypes, A and B, were observed, of which the former was present in 70–90 % of all the sheep examined. These two phenotypes have been shown to be controlled by a single autosomal locus, with two alleles LayA and LapB . The LapA allele is dominant. The frequencies of Lap phenotypes and alleles were determined in eleven Spanish and two foreign breeds. Serum alkaline phospatase and serum leucine aminopeptidase are electrophoretically distinct. 相似文献
7.
David A. Young 《Biochemical Systematics and Ecology》1982,10(1):21-22
The leaf flavonoids of Amborella trichopoda were examined and two kaempterol glycosides were detected. Procyanidin was also present. These results are similar to the flavonoid pattern in other families of the Laurales and it is suggested that simple flavonol glycosides are a primitive feature in the order. 相似文献
8.
Vanderlan Da S. Bolsani Maria Fátima Das G.F. Da Silva Arnaldo I. Da Rocha Otto R. Gottlieb 《Biochemical Systematics and Ecology》1984,12(2):159-166
Indole alkaloids can be characterized by skeletal specialization (S), determined upon consideration of their relative position on a biogenetic map and the number of their naturally occurring substitutional derivatives, as well as by oxidation level (O). The mean (S) and (O) for contained alkaloids of a given plant taxon are taken to represent evolutionary advancement parameters, respectively EAs and EAo.A correlation of these EAs/EAo values for tribes of the Apocynaceae-Plumerioideae reveals a chemical gradient, given by gradually increasing EAs and EAo values, to link Carisseae-Alstonieae-Rauvolfieae-Tabernaemontaneae. 相似文献
9.
This study was designed for investigating the effect of Asparagus racemosus (AR) extract and chitosan (CTN) in facilitating the permeation of carvedilol (CDL) across rat epidermis. Transdermal flux
of carvedilol through heat-separated rat epidermis was investigated in vitro using vertical Keshary–Chien diffusion cells. Biophysical and microscopic manifestations of epidermis treated with AR extract,
CTN, and AR extract–CTN mixture were investigated by using differential scanning calorimetry, transepidermal water loss, scanning
electron microscopy (SEM), and transmission electron microscopy (TEM). Biochemical estimations of cholesterol, sphingosine,
and triglycerides were carried out for treated excised as well as viable rat epidermis. The antihypertensive activity of the
patches in comparison with that of oral carvedilol was studied in deoxycorticosterone acetate-induced hypertensive rats. The
permeation of carvedilol across excised rat epidermis was significantly higher (p < 0.05) when AR extract, CTN, or AR extract–CTN mixture was used as donor vehicle as compared to propylene glycol/ethanol
(7:3) mixture. Epidermis obtained after 12 h treatment of viable rat skin with AR extract–CTN mixture showed significantly
higher (p < 0.05) permeability to CDL as compared to that after treatment with AR extract or CTN alone. Further, the application of
patches containing AR extract–CTN mixture resulted in sustained release of CDL which was able to control the hypertension
in deoxycorticosterone acetate-induced hypertensive rats through 36 h. Estimation of micro constituents in rat epidermis revealed
maximum extraction of cholesterol, sphingosine, and triglycerides after treatment with AR extract–CTN mixture. This was manifested
in altered lipid and protein-specific thermotropic transitions. Further, increase in intercellular space, disordered lipid
structure, and corneocyte detachment as observed in SEM and TEM suggested great potential of AR extract for use as percutaneous
permeation enhancer. The developed transdermal patches of CDL containing AR extract–CTN mixture exhibited better performance
as compared to oral administration in controlling hypertension in rats. 相似文献
10.