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1.
C C Clark E A Tomichek T R Koszalka R R Minor N A Kefalides 《The Journal of biological chemistry》1975,250(13):5259-5267
Basement membrane biosynthesis in vitro was studied in a rapidly growing embryonic tissue, the rat parietal yolk sac. This tissue consists of a thick, nonvascular basement membrane (Reichert's membrane) separating two cellular layers (parietal endoderm and trophoblast). Morphologically, Reichert's membrane appeared similar to other basement membranes. Previous analysis of the amino acid and carbohydrate composition of acellular Reichert's membrane showed it to be typical of basement membranes isolated from other tissues and species. Analysis of [14-C]proline incorporation and hydroxy [14-C]proline synthesis during the third quarter ogestation in vitro showed that basement membrane collagen synthesis in the parietal yolk sac was maximal around the 14th day of gestation. At this time, basement membrane collagen represented nearly 10% of the newly synthesized protein. The collagen synthesized in this system was characteristic of basement membrane collagen in that about 11% of the total hydroxy [14-C]proline was present as the 3-isomer. In addition, after incubation in the presence of [14-C]lysine, 83 to 94% of the hydroxy[14-C]lysine was glycosylated, with the predominant form being glucosylgalactosylhydroxy[14-C]lysine. When the parietal endoderm and trophoblast were incubated separately with [14-C]proline, it was determined that the former was solely responsible for the synthesis of basement membrane collagen since essentially all of the 4-hydroxy[14-C]proline was associated with this cell type. Autoradiographic experiments with [3-H]glucosamine also served to localize the synthesis of noncollagen basement membrane glycoprotein components to the parietal endoderm. As with the results reported for basement membrane collagen secretion in embryonic chick lens cells, there appeared to be approximately a 60-min delay between the incorporation of [14-C]proline into protein and the secretion of collagen as measured by the appearance of 4-hydroxy[14-C]proline in the culture medium. Experiments utilizing [3H]glucosamine to monitor glycoprotein synthesis did not show a delay between the incorporation of [3H]glucosamine and the secretion of nondialyzable 3-H into the medium. The results obtained using the parietal yolk sac system to study basement membrane biosynthesis were compared to those previously obtained using the kidney glomerular and embryonic chick lens systems. It was concluded that the parietal yolk sac system is superior for a number of reasons: (a) the extracellular matrix appeared to contain only basement membrane components; there was no contamination by acid mucopolysaccharides or other types of collagen; (b) only a single cell type appeared to be responsible for the synthesis of basement membrane components; and (c) a relatively large percentage of the newly synthesized protein was basement membrane collagen. 相似文献
2.
MHC (major histocompatibility complex) class I molecules bind intracellular virus-derived peptides in the endoplasmic reticulum (ER) and present them at the cell surface to cytotoxic T lymphocytes. Peptide-free class I molecules at the cell surface, however, could lead to aberrant T cell killing. Therefore, cells ensure that class I molecules bind high-affinity ligand peptides in the ER, and restrict the export of empty class I molecules to the Golgi apparatus. For both of these safeguard mechanisms, the MHC class I loading complex (which consists of the peptide transporter TAP, the chaperones tapasin and calreticulin, and the protein disulfide isomerase ERp57) plays a central role. This article reviews the actions of accessory proteins in the biogenesis of class I molecules, specifically the functions of the loading complex in high-affinity peptide binding and localization of class I molecules, and the known connections between these two regulatory mechanisms. It introduces new models for the mode of action of tapasin, the role of the class I loading complex in peptide editing, and the intracellular localization of class I molecules. 相似文献
3.
Abdullah Mohib Sliwinska Elwira Góralski Grzegorz Latocha Piotr Tuleja Monika Widyna Patrycja Popielarska-Konieczna Marzena 《Plant Cell, Tissue and Organ Culture》2021,147(3):569-582
Plant Cell, Tissue and Organ Culture (PCTOC) - Endosperm, an ephemeral and storage tissue, serves as a source of nutrition and protection during embryo development and germination. It can be used... 相似文献
4.
Cultured fibroblast cells, especially dermal cells, are used for various types of scientific research, particularly within the medical field. Desirable features of the cells include their ease of isolation, rapid cellular growth, and high degree of robustness. Currently, fibroblasts are mainly used to obtain pluripotent cells via a reprogramming process. Dermal fibroblasts, are particularly useful for gene therapies used for promoting wound healing or minimizing skin aging. In recent years, fibroblast transfection efficiencies have significantly improved. In order to introduce molecules (most often DNA or RNA) into cells, viral-based systems (transduction) or non-viral methods (transfection) that include physical/mechanical processes or lipid reagents may be used. In this article, we describe critical points that should be considered when selecting a method for transfecting fibroblasts. The most effective methods used for the transfection of fibroblasts include both viral-based and non-viral nucleofection systems. These methods result in a high level of transgene expression and are superior in terms of transfection efficacy and viability. 相似文献
5.
Patrycja Mantaj Grzegorz Zwierzchowski 《Reports of Practical Oncology and Radiotherapy》2013,18(3):139-147
Aim
The aim of the study was to verify the dose distribution optimisation method in pulsed brachytherapy.Background
The pulsed-dose rate brachytherapy is a very important method of breast tumour treatment using a standard brachytheraphy equipment. The appropriate dose distribution round an implant is an important issue in treatment planning. Advanced computer systems of treatment planning are equipped with algorithms optimising dose distribution.Materials and methods
The wax-paraffin phantom was constructed and seven applicators were placed within it. Two treatment plans (non-optimised, optimised) were prepared. The reference points were located at a distance of 5 mm from the applicators’ axis. Thermoluminescent detectors were placed in the phantom at suitable 35 chosen reference points.Results
The dosimetry verification was carried out in 35 reference points for the plans before and after optimisation. Percentage difference for the plan without optimisation ranged from −8.5% to 1.4% and after optimisation from −8.3% to 0.01%. In 16 reference points, the calculated percentage difference was negative (from −8.5% to 1.3% for the plan without optimisation and from −8.3% to 0.8% for the optimised plan). In the remaining 19 points percentage difference was from 9.1% to 1.4% for the plan without optimisation and from 7.5% to 0.01% for the optimised plan.No statistically significant differences were found between calculated doses and doses measured at reference points in both dose distribution non-optimised treatment plans and optimised treatment plans.Conclusions
No statistically significant differences were found in dose values at reference points between doses calculated by the treatment planning system and those measured by TLDs. This proves the consistency between the measurements and the calculations. 相似文献6.
Patrycja M. Dubielecka Anna Trusz Witold Diakowski Michał Grzybek Anna Chorzalska Bozena Jaźwiec 《Molecular membrane biology》2013,30(3):235-243
Understanding drug-membrane and drug-membrane protein interactions would be a crucial step towards understanding the action and biological properties of anthracyclines, as the cell membrane with its integral and peripheral proteins is the first barrier encountered by these drugs. In this paper, we briefly describe mitoxantrone-monolayer and mitoxantrone-bilayer interactions, focusing on the effect of mitoxantrone on the interactions between erythroid or nonerythroid spectrin with phosphatidylethanolamine-enriched mono- and bilayers. We found that mitoxantrone markedly modifies the interaction of erythroid and nonerythroid spectrins with phosphatidylethanolamine/phosphatitydcholine (PE/PC) monolayers. The change in Δπ induced by spectrins is several-fold larger in the presence of 72?nM mitoxantrone than in its absence: spectrin/mitoxantrone complexes induced a strong compression of the monolayer. Spin-labelling experiments showed that spectrin/mitoxantrone complexes caused significant changes in the order parameter measured using a 5′-doxyl stearate probe in the bilayer, but they practically did not affect the mobility of 16′-doxyl stearate. These results indicate close-to-surface interactions/penetrations without significant effect on the mid-region of the hydrophobic core of the bilayer. The obtained apparent equilibrium dissociation constants indicated relatively similar mitoxantrone-phospholipid and mitoxantrone-spectrin (erythroid and nonerythroid) binding affinities. These results might in part, explain the effect of mitoxantrone on spectrin distribution in the living cells. 相似文献
7.
Edyta Paradowska Agnieszka Jab?ońska Miros?awa Studzińska Katarzyna Skowrońska Patrycja Suski Ma?gorzata Wi?niewska-Ligier Teresa Wo?niakowska-G?sicka Dorota Nowakowska Zuzanna Gaj Jan Wilczyński Zbigniew J. Le?nikowski 《PloS one》2016,11(4)
Toll-like receptor 9 (TLR9) recognizes non-methylated viral CpG-containing DNA and serves as a pattern recognition receptor that signals the presence of human cytomegalovirus (HCMV). Here, we present the genotype distribution of single-nucleotide polymorphisms (SNPs) of the TLR9 gene in infants and the relationship between TLR9 polymorphisms and HCMV infection. Four polymorphisms (-1237T/C, rs5743836; -1486T/C, rs187084; 1174G/A, rs352139; and 2848C/T, rs352140) in the TLR9 gene were genotyped in 72 infants with symptomatic HCMV infection and 70 healthy individuals. SNP genotyping was performed by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Digested fragments were separated and identified by capillary electrophoresis. The HCMV DNA copy number was measured by a quantitative real-time PCR assay. We found an increased frequency of heterozygous genotypes TLR9 -1486T/C and 2848C/T in infants with HCMV infection compared with uninfected cases. Heterozygous variants of these two SNPs increased the risk of HCMV disease in children (P = 0.044 and P = 0.029, respectively). In infants with a mutation present in at least one allele of -1486T/C and 2848C/T SNPs, a trend towards increased risk of cytomegaly was confirmed after Bonferroni’s correction for multiple testing (Pc = 0.063). The rs352139 GG genotype showed a significantly reduced relative risk for HCMV infection (Pc = 0.006). In contrast, the -1237T/C SNP was not related to viral infection. We found no evidence for linkage disequilibrium with the four examined TLR9 SNPs. The findings suggest that the TLR9 -1486T/C and 2848C/T polymorphisms could be a genetic risk factor for the development of HCMV disease. 相似文献
8.
Patrycja Rogala Grzegorz Czerwonka Sawomir Michakiewicz Maciej Hodorowicz Barbara Barszcz Agnieszka Jaboska‐Wawrzycka 《化学与生物多样性》2019,16(11)
The antibacterial and antibiofilm activities of two new ruthenium complexes against E. coli, S. aureus, P. aeruginosa PAO1 (laboratory strain) and P. aeruginosa LES B58 (clinical strain) were evaluated. Complexes, mer‐[RuIII(2‐bimc)3] ? H2O ( 1 ) and cis‐[RuIVCl2(2,3‐pydcH)2] ? 4H2O ( 2 ), were obtained using aromatic carboxylic acid ligands, namely, 1H‐benzimidazole‐2‐carboxylic acid (2‐bimcH) and pyridine‐2,3‐dicarboxylic acid (2,3‐pydcH2). Compounds were physicochemically characterized using X‐ray diffraction, Hirshfeld surface analysis, IR and UV/VIS spectroscopies, as well as magnetic and electrochemical measurements. Structural characterization revealed that Ru(III) and Ru(IV) ions in the complexes adopt a distorted octahedral geometry. The intermolecular classical and weak hydrogen bonds, and π???π contacts significantly contribute to structure stabilization, leading to the formation of a supramolecular assembly. Biological studies have shown that the Ru complexes inhibit the growth of bacteria and biofilm formation by the tested strains and the complexes seem to be a potential as antimicrobial agents. 相似文献
9.
Piotr Indykiewicz Patrycja Podlaszczuk Maciej Kamiski Radosaw Wodarczyk Piotr Minias 《Ibis》2019,161(4):744-758
Central nesting sites within avian colonies are often more profitable in terms of fitness, as they can offer better protection against predators compared with colony edges. Thus, central sites are expected to attract high‐quality individuals, which should produce a clear central–periphery gradient in the phenotypic quality of nesting individuals and reproductive output within colonies. The aim of this study was to assess spatial patterns of individual quality within a colony of a common larid, the Black‐headed Gull Chroicocephalus ridibundus. We found that laying was advanced in the central zone of the colony when compared with the periphery, and central pairs tended to lay larger eggs and had higher hatching success than peripheral pairs. Centrally nesting individuals had higher blood haemoglobin concentrations, size‐corrected body mass and heterozygosity (males only), indicating their better condition and higher genetic quality. In contrast, central females had lower plasma albumin concentration, which could possibly be attributed to their greater investment in egg production. Finally, pairs breeding in the central zone of the colony had an elevated heterophil/lymphocyte ratio, suggesting that social stress can be recognized as an important cost of nesting in dense aggregations. The results provide empirical support for central–periphery gradients in the individual quality of colonially nesting Black‐headed Gulls, indicating that spatial gradients in pair quality should be carefully taken into account when conducting research on colonial birds. 相似文献
10.