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81.
In situ analysis of native microbial communities in complex samples with high particulate loads 总被引:1,自引:0,他引:1
In the present study a procedure combining a cell extraction method and Fluorescence In Situ Hybridization (FISH) for molecular monitoring and quantification of bacteria in soil and aquifer samples is presented. FISH was applied to bacterial cells extracted from the matrix by density gradient centrifugation. This separation method was applied to soil and aquifer samples and produced high cell recovery of 76.5%+/-4.4 and 78.0%+/-3.2, respectively. FISH, performed on the harvested cells, permitted a perfect visualization and quantification of bacteria. This approach is therefore promising for in situ detection of indigenous bacterial communities in complex samples. 相似文献
82.
Chlamydia trachomatis remains one of the few major human pathogens for which there is no transformation system. C. trachomatis has a unique obligate intracellular developmental cycle. The extracellular infectious elementary body (EB) is an infectious, electron-dense structure that, following host cell infection, differentiates into a non-infectious replicative form known as a reticulate body (RB). Host cells infected by C. trachomatis that are treated with penicillin are not lysed because this antibiotic prevents the maturation of RBs into EBs. Instead the RBs fail to divide although DNA replication continues. We have exploited these observations to develop a transformation protocol based on expression of β-lactamase that utilizes rescue from the penicillin-induced phenotype. We constructed a vector which carries both the chlamydial endogenous plasmid and an E.coli plasmid origin of replication so that it can shuttle between these two bacterial recipients. The vector, when introduced into C. trachomatis L2 under selection conditions, cures the endogenous chlamydial plasmid. We have shown that foreign promoters operate in vivo in C. trachomatis and that active β-lactamase and chloramphenicol acetyl transferase are expressed. To demonstrate the technology we have isolated chlamydial transformants that express the green fluorescent protein (GFP). As proof of principle, we have shown that manipulation of chlamydial biochemistry is possible by transformation of a plasmid-free C. trachomatis recipient strain. The acquisition of the plasmid restores the ability of the plasmid-free C. trachomatis to synthesise and accumulate glycogen within inclusions. These findings pave the way for a comprehensive genetic study on chlamydial gene function that has hitherto not been possible. Application of this technology avoids the use of therapeutic antibiotics and therefore the procedures do not require high level containment and will allow the analysis of genome function by complementation. 相似文献
83.
84.
Differential toxicity of TAR DNA‐binding protein 43 isoforms depends on their submitochondrial localization in neuronal cells 下载免费PDF全文
Illari Salvatori Alberto Ferri Silvia Scaricamazza Ilaria Giovannelli Alessia Serrano Simona Rossi Nadia D'Ambrosi Mauro Cozzolino Andrea Di Giulio Sandra Moreno Cristiana Valle Maria Teresa Carrì 《Journal of neurochemistry》2018,146(5):585-597
85.
FOXM1 Transcription Factor: A New Component of Chronic Myeloid Leukemia Stem Cell Proliferation Advantage 下载免费PDF全文
Manuela Mancini Fausto Castagnetti Simona Soverini Elisa Leo Caterina De Benedittis Gabriele Gugliotta Gianantonio Rosti Luana Bavaro Sara De Santis Cecilia Monaldi Margherita Martelli Maria Alessandra Santucci Michele Cavo Giovanni Martinelli 《Journal of cellular biochemistry》2017,118(11):3968-3975
86.
Glasses in the system xGd2O3·(100-x)[GeO2·V2O5] with 0 ≤ × ≤ 20 mol% have been prepared from the melt quenching method. In this paper, we investigated changes in germanium
coordination number in gadolinium-vanadate-germanate glasses through molar volume analysis, measurements of densities, investigations
of FTIR and UV-VIS spectroscopy, calculations of density functional theory (DFT). Analyzing the structural changes resulted
from the IR spectra we found that the gadolinium ions have a pronounced affinity toward [VO4] structural units which contain non-bridging oxygens necessary for the charge compensation. The introduction of the excess
of oxygen yields the formation of [VO5] structural units. This attains maximum value at 5 mol% Gd2O3, in agreement with the density measurements. Further, the addition of the surplus of oxygen implies the transformation of
[VO5] to [VO4] structural units and the formation of VO4−3 orthovanadate structural units. The UV-VIS spectra show a broad UV absorption band located in the 300–500 nm region. These
bands are assumed to originate from the combination of vanadium ions possibly present in the three states of valence. The
presence of Ge-Ge wrong bonds attains its maximum values in the samples with x = 5 and 15 mol% Gd2O3 (bands centered in the 250–300 nm range). DFT calculations show the massive vibrations of the [VOn] structural units coupled with each other via [GeO6] and [GeO4] structural units. This leads to the splitting of the bridge modes and a multiplication of the number of these bands. 相似文献
87.
Alice Toso Simona Schifano Charlotte Oxborough Krista McGrath Luke Spindler Anabela Castro Lucy Evangelista Vanessa Filipe Maria José Gonçalves Antonio Marques Inês Mendes da Silva Raquel Santos Maria João Valente Iona McCleery Michelle Alexander 《American journal of physical anthropology》2021,176(2):208-222
88.
Olszak AM van Essen D Pereira AJ Diehl S Manke T Maiato H Saccani S Heun P 《Nature cell biology》2011,13(7):799-808
89.
The pendrin (SLC26A4 or PDS) gene is responsible, when mutated, for the Pendred syndrome, a recessive disorder characterized by sensorineural hearing loss often accompanied by thyroid dysfunctions. Pendrin protein is an anion exchanger and we focused on a still unexplored function that it might play in view of its importance in the inner ear: Cl(-) fluxes regulation during cellular volume control. We challenged HEK-293 Phoenix cells over-expressing wild type pendrin (PDS HEK cells) together with the EYFP (Enhanced Yellow Fluorescent Protein) or over-expressing the EYFP alone (control HEK cells) with hypo-osmolar solutions. Taking advantage of the confocal optical sectioning we measured the cell volume. In addition, we determined the intracellular pH and chloride concentration with fluorescent probes (EYFP and seminaphthorhodafluor-5F, SNARF-5F). Consequently, we could estimate simultaneously Cl(-) fluxes, cellular volume and intracellular pH variations. Cl(-) movements markedly differed between PDS and control HEK cells upon hypotonic shock and are accompanied by an attenuation of the swelling induced pH drop in PDS HEK cells. The contemporary measurements of the three variables not yet reported in living cells, allowed to assess a possible influence of pendrin upregulation in volume homeostasis and evidenced its participation to Cl(-) fluxes. 相似文献
90.
Serini S Donato V Piccioni E Trombino S Monego G Toesca A Innocenti I Missori M De Spirito M Celleno L Fasano E Ranelletti FO Calviello G 《The Journal of nutritional biochemistry》2011,22(9):874-885
The dramatic increase in the incidence of nonmelanoma skin cancer over the last decades has been related to the augmented exposure to ultraviolet (UV) radiation (UVR). It is known that apoptosis is induced as a protective mechanism after the acute irradiation of keratinocytes, whereas apoptotic resistance and carcinogenesis may follow the chronic exposure to UVR. We found that not all the human keratinocytes lines studied underwent apoptosis following acute exposure to UVR (10-60 mJ/cm2). Whereas UVR induced apoptosis in the HaCaT cells, NCTC 2544 and nr-HaCaT cells showed apoptosis resistance. The cytokeratin pattern of the apoptosis-resistant cells indicated that they possessed a degree of differentiation lower than that of HaCaT cells. They also showed an enhanced expression of cyclooxygenase-2 (COX-2), an early marker of carcinogenesis in various tissues, including skin. n-3 polyunsaturated fatty acids have drawn increasing interest as nutritional factors with the potential to reduce UVR carcinogenesis, and since they are apoptosis inducers and COX-2 inhibitors in cancer cells, we investigated the ability of n-3 polyunsaturated fatty acids to influence the resistance to UVR-induced apoptosis in keratinocytes. We observed that docosahexaenoic acid (DHA) reverted the resistance of nr-HaCaT cells to UVR-induced apoptosis, increasing the Bax/Bcl-2 ratio and caspase-3 activity, and reduced COX-2 levels by inhibiting the expression of the human antigen R (HuR), a known COX-2 mRNA stabilizer in keratinocytes. The transfection of nr-HaCaT cells with HuR siRNA mimicked the proapoptotic effect of DHA. Overall, our findings further support the role of DHA as a suitable anticarcinogenic factor against nonmelanoma skin cancers. 相似文献