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11.
Summary Iodination of proteins and lipoproteins is a widely used in vitro labelling procedure in metabolic, autoradiographic and various other studies. However, all available iodination techniques have involved the possible damage to the proteins by self-irradiation, oxidizing agents, the alkaline milieu or by the introduction of iodine into the molecular structure itself. To evaluate the integrity of iodinated lipoproteins, we observed the electron microscopic appearance of normal and iodinated rabbit very low density lipoproteins (VLDL) by negative staining with phosphotungstic acid. Iodination up to a molar iodine/protein ratio of 2.89 did not result in any change of shape, size or aggregating tendency of the particles. No stacks or disk-like particles like those of various hyperlipoproteinemic states were found. We conclude that electron microscopy is a valuable tool in assessing the morphological appearance of lipoprotein iodination, but it should be complemented by other techniques. 相似文献
12.
Trying to understand axonal regeneration in the CNS of fish. 总被引:7,自引:0,他引:7
In contrast to the situation in mammals and birds, neurons in the central nervous system (CNS) of fish--such as the retinal ganglion cells--are capable of regenerating their axons and restoring vision. Special properties of the glial cells and the neurons of the fish visual pathway appear to contribute to the success of axonal regeneration. The fish oligodendrocytes lack the axon growth inhibiting molecules that interfere with axonal extension in mammals. Instead, fish optic nerve oligodendrocytes support--at least in vitro--axonal elongation of fish as well as that of rat retinal axons. Moreover, the fish retinal ganglion cells re-express upon injury a set of growth-associated cell surface molecules and equip the regenerating axons throughout their path and up into their target, the tectum opticum with these molecules. This may indicate that the injured fish ganglion cells reactivate the cellular machinery necessary for axonal regrowth and pathfinding. Furthermore, the target itself provides positional marker molecules even in adult fish. These marker molecules are required to guide the regenerating axons back to their retinotopic home territory within the tectum. 相似文献
13.
Eduard Kühn Rudi Van Cauwenbergh Leo Huybrechts Hendrik Deelstra 《Biological trace element research》1992,32(1-3):289-292
Plasma concentrations of cGH, T3, and T4 were not different between dwarf and normal broiler breeders. Normal hens had a liver selenium content of 710±35 ng/g, and
dwarf hens 656 ±nine ng/g (n=8). Following injections into a wing vein of different doses (1.5, 3, 6, 12, and 24 μg/kg) of the hypothalamic hormone TRH,
GH was increased after 15 min. This effect seemed to last longer in dwarf chickens. Plasma concentrations of T3 increased significantly 1 h after TRH in normal hens, but TRH was ineffective in raising T3 levels in dwarf animals. The selenium content of livers obtained following decapitation after 2 h was also increased in normal
hens up to 902±42 ng/g using the highest dose of TRH (24 μg/kg). This seemed not to be the case for dwarf animals. A much
smaller. number of hepatic cGH receptors was also found in dwarf hens, whereas the affinity of the hepatic GH receptor was
not influenced by the genotype. It is concluded that the sex-linked dwarf hens are unable to increase their hepatic T4 into T3 conversion following a TRH challenge probably because of a deficiency in hepatic GH receptors. The lower content of selenium
in dwarfs and their inability to increase its uptake after TRH seem therefore to support the hypothesis that selenium has
a direct role in the activity of the 5′-deiodinase complex. 相似文献
14.
Dagmar Jičínská Eduard Brabec Marcel Rejmánek Jan Jeník Joří Haager Josef Holub Věroslav Samek Hana Rambousková Josef Holub Marie Naděžda Končalová Robert Neuhäusl Josev Kyncl František Krahuleo Jaroslav Dobrý Blanka Úlehlová Jiří Úlehla Eliška Rybníčková Kamil Rybníček 《Folia Geobotanica》1982,17(4):431-448
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Syatkin Sergey P. Neborak Ekaterina V. Khlebnikov Andrei I. Komarova Marina V. Shevkun Natalia A. Kravtsov Eduard G. Blagonravov Mikhail L. Agostinelli Enzo 《Amino acids》2020,52(2):199-211
Amino Acids - The polyamine (PA) metabolism is involved in cell proliferation and differentiation. Increased cellular PA levels are observed in different types of cancers. Products of PA oxidation... 相似文献
18.
Kalocayova Barbora Snurikova Denisa Vlkovicova Jana Navarova-Stara Veronika Michalikova Dominika Ujhazy Eduard Gasparova Zdenka Vrbjar Norbert 《Molecular and cellular biochemistry》2021,476(12):4323-4330
Molecular and Cellular Biochemistry - Previously it was shown that for reduction of anxiety and stress of experimental animals, preventive handling seems to be one of the most effective methods.... 相似文献
19.
Emilie Lecomte Sylvie Saleun Mathieu Bolteau Aurélien Guy-Duché Oumeya Adjali Véronique Blouin Magalie Penaud-Budloo Eduard Ayuso 《Biotechnology journal》2021,16(1):2000016
Adeno-associated viral vectors (AAV) are efficient engineered tools for delivering genetic material into host cells. The commercialization of AAV-based drugs must be accompanied by the development of appropriate quality control (QC) assays. Given the potential risk of co-transfer of oncogenic or immunogenic sequences with therapeutic vectors, accurate methods to assess the level of residual DNA in AAV vector stocks are particularly important. An assay based on high-throughput sequencing (HTS) to identify and quantify DNA species in recombinant AAV batches is developed. Here, it is shown that PCR amplification of regions that have a local GC content >90% and include successive mononucleotide stretches, such as the CAG promoter, can introduce bias during DNA library preparation, leading to drops in sequencing coverage. To circumvent this problem, SSV-Seq 2.0, a PCR-free protocol for sequencing AAV vector genomes containing such sequences, is developed. The PCR-free protocol improves the evenness of the rAAV genome coverage and consequently leads to a more accurate relative quantification of residual DNA. HTS-based assays provide a more comprehensive assessment of DNA impurities and AAV vector genome integrity than conventional QC tests based on real-time PCR and are useful methods to improve the safety and efficacy of these viral vectors. 相似文献
20.
Christian Schimper Rupert Keckeis Eduard Burtscher Avinash P. Manian 《Biocatalysis and Biotransformation》2013,31(5-6):383-389
Cellulosic fabric samples of cotton, viscose, lyocell and modal were pretreated with steam and dry heat in the range of 100–190°C. The samples were then treated with a Trichoderma reesei cellulase preparation (total culture filtrate – TC), with mechanical agitation, at a high enzyme dosage of 75% by weight of fabric, for 8 hours. Generally, viscose proved to be easily degradable, followed by cotton and modal. The degree of hydrolysis was the least for Lyocell. Dry heat pretreatments exerted a lower influence on degradation rate than steam pretreatments which showed a distinct maximum at a steam temperature of 130°C. The hydrolysis rate varied strongly depending on treatment conditions and fibre type. Water retention values in treated substrates were changed by up to 20% of initial values. 相似文献