排序方式: 共有38条查询结果,搜索用时 46 毫秒
31.
Ivić-Kolevska S Miljković-Selimović B Kocić B 《Acta microbiologica et immunologica Hungarica》2012,59(2):185-198
The aim of this study was to determine the survival of Campylobacter jejuni in chicken meat samples at frozen temperatures and given length of incubation and to determine the impact of aerobic bacteria on the survival of C. jejuni. The chicken meat samples were inoculated with C. jejuni NCTC 11351 suspensions and stored in bags at temperatures of -20°C and -70°C. The mean value of C. jejuni from meat samples decreased from 7.52 log10 CFU/g after 30 minutes of incubation at ambient temperature, to 3.87 log10 CFU/g on the eighth week of incubation at -20°C, and to 3.78 log10 CFU/g at incubation at -70°C after the same incubation period. Both freezing temperatures, -20°C and -70°C, decreased the number of campylobacters. The presence of aerobic mesophilic bacteria did not influence the survival of C. jejuni in chicken meet samples. Keeping poultry meat at freezing temperatures is important for the reduction of C. jejuni, which has a strong influence on the prevention of occurrence of campylobacteriosis in humans. 相似文献
32.
33.
To understand astrovirus biology, it is essential to understand factors associated with its evolution. The current study reports the genomic sequences of nine novel turkey astrovirus (TAstV) type 2-like clinical isolates. This represents, to our knowledge, the largest genomic-length data set available for any one astrovirus type. The comparison of these TAstV sequences suggests that the TAstV species contains multiple subtypes and that recombination events have occurred across the astrovirus genome. In addition, the analysis of the capsid gene demonstrated evidence for both site-specific positive selection and purifying selection. 相似文献
34.
Choi BK Actor JK Rios S d'Anjou M Stadheim TA Warburton S Giaccone E Cukan M Li H Kull A Sharkey N Gollnick P Kocieba M Artym J Zimecki M Kruzel ML Wildt S 《Glycoconjugate journal》2008,25(6):581-593
Traditional production of therapeutic glycoproteins relies on mammalian cell culture technology. Glycoproteins produced by mammalian cells invariably display N-glycan heterogeneity resulting in a mixture of glycoforms the composition of which varies from production batch to production batch. However, extent and type of N-glycosylation has a profound impact on the therapeutic properties of many commercially relevant therapeutic proteins making control of N-glycosylation an emerging field of high importance. We have employed a combinatorial library approach to generate glycoengineered Pichia pastoris strains capable of displaying defined human-like N-linked glycans at high uniformity. The availability of these strains allows us to elucidate the relationship between specific N-linked glycans and the function of glycoproteins. The aim of this study was to utilize this novel technology platform and produce two human-like N-linked glycoforms of recombinant human lactoferrin (rhLF), sialylated and non-sialylated, and to evaluate the effects of terminal N-glycan structures on in vitro secondary humoral immune responses. Lactoferrin is considered an important first line defense protein involved in protection against various microbial infections. Here, it is established that glycoengineered P. pastoris strains are bioprocess compatible. Analytical protein and glycan data are presented to demonstrate the capability of glycoengineered P. pastoris to produce fully humanized, active and immunologically compatible rhLF. In addition, the biological activity of the rhLF glycoforms produced was tested in vitro revealing the importance of N-acetylneuraminic (sialic) acid as a terminal sugar in propagation of proper immune responses. 相似文献
35.
Mihajlo Gajić Budimir S. Ilić Bojan P. Bondžić Zdravko Džambaski Vesna V. Kojić Dimitar S. Jakimov Gordana Kocić Andrija Šmelcerović 《化学与生物多样性》2021,18(8):e2100261
Herein we report an assessment of 24 1,2,3,4-tetrahydroisoquinoline derivatives for potential DNase I (deoxyribonuclease I) inhibitory properties in vitro. Four of them inhibited DNase I with IC50 values below 200 μM. The most potent was 1-(6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolin-1-yl)propan-2-one ( 2 ) (IC50=134.35±11.38 μM) exhibiting slightly better IC50 value compared to three other active compounds, 2-[2-(4-fluorophenyl)-1,2,3,4-tetrahydroisoquinolin-1-yl]-1-phenylethan-1-one ( 15 ) (IC50=147.51±14.87 μM), 2-[2-(4-fluorophenyl)-1,2,3,4-tetrahydroisoquinolin-1-yl]cyclohexan-1-one ( 18 ) (IC50=149.07±2.98 μM) and 2-[6,7-dimethoxy-2-(p-tolyl)-1,2,3,4-tetrahydroisoquinolin-1-yl]cyclohexan-1-one ( 22 ) (IC50=148.31±2.96 μM). Cytotoxicity assessment of the active DNase I inhibitors revealed a lack of toxic effects on the healthy cell lines MRC-5. Molecular docking and molecular dynamics simulations suggest that interactions with Glu 39, His 134, Asn 170, Tyr 211, Asp 251 and His 252 are an important factor for inhibitors affinity toward the DNase I. Observed interactions would be beneficial for the discovery of new active 1,2,3,4-tetrahydroisoquinoline-based inhibitors of DNase I, but might also encourage researchers to further explore and utilize potential therapeutic application of DNase I inhibitors, based on a versatile role of DNase I during apoptotic cell death. 相似文献
36.
Z Drahota H Rauchová V Sedlák J Koci Z Cervinková 《Physiological research / Academia Scientiarum Bohemoslovaca》1999,48(2):167-170
The increase of the membrane fluidity during the early phase of liver regeneration after partial hepatectomy was described in literature in plasma membrane and in microsomes. We found similar changes also in isolated mitochondria and in crude total membrane fraction of the liver homogenate. The administration of triiodothyronine to rats before partial hepatectomy diminished the increase of the membrane fluidity in the regenerating liver by 50%. Triiodothyronine effect is explained by hormonal modification of lipid metabolism in the regenerating liver. 相似文献
37.
G. Bjelaković I. Stojanović T. Jevtović Stoimenov D. Pavlović G. Kocić S. Rossi C. Tabolacci J. Nikolić D. Sokolović Lj. Bjelakovic 《Amino acids》2010,39(1):29-43
Glucocorticoid hormones (GC) are essential in all aspects of human health and disease. Their anti-inflammatory and immunosuppressive
properties are reasons for therapeutic application in several diseases. GC suppress immune activation and uncontrolled overproduction
and release of cytokines. GC inhibit the release of pro-inflammatory cytokines and stimulate the production of anti-inflammatory
cytokines. Investigation of GC’s mechanism of action, suggested that polyamines (PA) may act as mediators or messengers of
their effects. Beside glucocorticoids, spermine (Spm) is one of endogenous inhibitors of cytokine production. There are many
similarities in the metabolic actions of GC and PA. The major mechanism of GC effects involves the regulation of gene expression.
PA are essential for maintaining higher order organization of chromatin in vivo. Spermidine and Spm stabilize chromatin and
nuclear enzymes, due to their ability to form complexes with negatively charged groups on DNA, RNA and proteins. Also, there is an increasing body of evidence that GC and PA change the chromatin structure especially through acetylation
and deacetylation of histones. GC display potent immunomodulatory activities, including the ability to induce T and B lymphocyte
apoptosis, mediated via production of reactive oxygen species (ROS) in the mitochondrial pathway. The by-products of PA catabolic
pathways (hydrogen peroxide, amino aldehydes, acrolein) produce ROS, well-known cytotoxic agents involved in programmed cell
death (PCD) or apoptosis. This review is an attempt in the better understanding of relation between GC and PA, naturally occurring
compounds of all eukaryotic cells, anti-inflammatory and apoptotic agents in physiological and pathological conditions connected
to oxidative stress or PCD. 相似文献
38.
S V Danshina L A Drachev A D Kaulen Kh G Korana T Marti T Mogi V I Skulachev 《Biokhimii?a (Moscow, Russia)》1992,57(10):1574-1585
It has been found that the N(P, R)-type intermediate of the photocycle is formed in the Asp-96-->Asn mutant at acidic pH. Azide, which strongly activates the M decay in this mutant, allows the N intermediate to be shown also at neutral pH. Under these conditions mutant N decays in a pH-independent fashion. In the presence of azide, the H+ uptake by Asp-96-->Asn mutant bacteriorhodopsin follows the M decay, whereas the N decay occurs at a much slower rate. Two electrogenic stages have been shown to be associated with the M--->bR step in the Asp-96--->Asn mutant photocycle. The faster and slower stages correlate with the M--->N and N--->bR transitions, respectively. In the Asp-96--->Asn mutant, high concentrations of azide are found to increase the M decay rate up to the values higher than those in the wild-type protein, both with or without azide. Such an effect is absent for the Asp-96-->Glu mutant. The activation energies for M--->N and N--->bR transitions in the wild-type protein are equal to 18 and 19 kcal x mole-1, respectively. In the Asp-96-->Asn mutant without azide, the activation energy of the M decay is only 5 kcal x mole-1, whereas in the presence of azide in this mutant the activation energies for M and N decays are 8 and 9 kcal x mole-1, respectively. A scheme of events accompanying the Schiff base reprotonation during the photocycle is discussed. 相似文献