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151.
Characterization of oxygen transfer in vertical microbubble columns for aerobic biotechnological processes
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152.
Aliaksandr A. Halavatyi Petr V. Nazarov Ziad Al Tanoury Vladimir V. Apanasovich Mikalai Yatskou Evelyne Friederich 《European biophysics journal : EBJ》2010,39(4):669-677
A novel mathematical model of the actin dynamics in living cells under steady-state conditions has been developed for fluorescence
recovery after photobleaching (FRAP) experiments. As opposed to other FRAP fitting models, which use the average lifetime
of actins in filaments and the actin turnover rate as fitting parameters, our model operates with unbiased actin association/dissociation
rate constants and accounts for the filament length. The mathematical formalism is based on a system of stochastic differential
equations. The derived equations were validated on synthetic theoretical data generated by a stochastic simulation algorithm
adapted for the simulation of FRAP experiments. Consistent with experimental findings, the results of this work showed that
(1) fluorescence recovery is a function of the average filament length, (2) the F-actin turnover and the FRAP are accelerated
in the presence of actin nucleating proteins, (3) the FRAP curves may exhibit both a linear and non-linear behaviour depending
on the parameters of actin polymerisation, and (4) our model resulted in more accurate parameter estimations of actin dynamics
as compared with other FRAP fitting models. Additionally, we provide a computational tool that integrates the model and that
can be used for interpretation of FRAP data on actin cytoskeleton. 相似文献
153.
154.
Al Ezaz Mamun Laurence C. Cantrill Robyn L. Overall Bruce G. Sutton 《Cell biology international》2010,34(5):469-476
Low‐temperature stress during microspore development alters cellular organization in rice anthers. The major cellular damage includes unusual starch accumulation in the plastids of the endothecium in postmeiotic anthers, abnormal vacuolation and hypertrophy of the tapetum, premature callose (1,3‐β‐glucan) breakdown and lack of normal pollen wall formation. These cellular lesions arise from damage to critical biochemical processes that include sugar metabolism in the anthers and its use by the microspores. Failure of utilization of the callose breakdown product and other microspore wall components like sporopollenin can also be considered as critical. In recent years, considerable progress has been made in the understanding of major biochemical processes including the expression of critical genes that are sensitive to low temperature in rice and cause male sterility. This paper combines a discussion of cellular organization and associated biochemical processes that are sensitive to low temperatures and provides an overview of the potential mechanisms of low‐temperature‐induced male sterility in rice. 相似文献
155.
Flavia Serpieri Andre Inocencio Jose Marcelino de Oliveira Alécio A. PimentaJr. Angélica Garbuio Jorge Kalil Marcelo M. Brigido Ana Maria Moro 《Molecular biotechnology》2010,45(3):218-225
Two humanized monoclonal antibody constructs bearing the same variable regions of an anti-CD3 monoclonal antibody, whole IgG
and FvFc, were expressed in CHO cells. Random and site-specific integration were used resulting in similar expression levels.
The transfectants were selected with appropriate selection agent, and the surviving cells were plated in semi-solid medium
for capture with FITC-conjugated anti-human IG antibody and picked with the robotic ClonePix FL. Conditioned media from selected
clones were purified by affinity chromatography and characterized by SDS-PAGE, Western-blot, SEC-HPLC, and isoelectric focusing.
Binding to the target present in healthy human mononuclear cells was assessed by flow cytometry, as well as by competition
between the two constructs and the original murine monoclonal antibody. The humanized constructs were not able to dislodge
the murine antibody while the murine anti-CD3 antibody could dislodge around 20% of the FvFc or IgG humanized versions. Further
in vitro and in vivo pre-clinical analyses will be carried out to verify the ability of the humanized versions to demonstrate
the immunoregulatory profile required for a humanized anti-CD3 monoclonal antibody. 相似文献
156.
Background: The seroprevalence rate of Helicobacter pylori in the Kingdom of Saudi Arabia (KSA) was reported to be in the range of 50–80% among mostly symptomatic patients in non‐community‐based studies. However, the seroprevalence of viral hepatitis A (HAV) underwent a marked decline in the last two decades from over 50% in 1989 to 25% in 1997 among Saudi children under the age of 12 years. The aim of this paper was to study seroprevalence rates of H. pylori and HAV among the adolescent population in three regions of KSA and to determine whether there was any correlation between them. Materials and methods: We randomly selected 1200 16–18‐year‐old students from three regions around KSA. Demographic data, including socioeconomic status (SES), were recorded, and each student was tested for the presence of H. pylori‐IgG antibodies and anti‐HAV‐IgG. Results: The results indicate a high H. pylori infection rate (47%) among this age group. Boys had a higher prevalence than girls (p = .03), and the Al‐Qaseem region had the highest prevalence (51%, p = .002). SES did not contribute to the high prevalence rates (p = .83). A cross‐tabulation of data showed that 88 (8%) of the teenagers were seropositive and that 512 (44%) were negative for both H. pylori and HAV antibodies (χ2 = 0.03, OR = 0.97, CI = 0.70–1.34). The agreement between H. pylori and HAV seropositivity was lower than would be predicted by chance (κ = ?0.03). The variables that were independently associated with seropositivity to H. pylori were being female (OR = 0.75, 95% CI = 0.60–0.95) and living in the Madinah region (OR = 0.72, 95% CI = 0.55–0.94). Conclusion: The prevalence of H. pylori in this group of adolescents was high. However, there was no correlation between H. pylori and HAV infection rates. Hence, factors contributing to the transmission source and route seem to be different. 相似文献
157.
Petr Novák Lukáš Žídek Veronika Motáčková Petr Padrta Alžběta Švenková Jean-Marc Nuzillard Libor Krásný Vladimír Sklenář 《Journal of biomolecular NMR》2010,46(2):191-197
S3EPY is a Python extension to the program Sparky written to facilitate the assessment of coupling constants from in-phase/antiphase
and spin-state-selective excitation (S3E) experiments. It enables the routine use of small scalar couplings by automating the coupling evaluation procedure. S3EPY
provides an integrated graphical user interface to programs which outputs graphs and the table of determined couplings. 相似文献
158.
Fischer H Lutay N Ragnarsdóttir B Yadav M Jönsson K Urbano A Al Hadad A Rämisch S Storm P Dobrindt U Salvador E Karpman D Jodal U Svanborg C 《PLoS pathogens》2010,6(9):e1001109
The mucosal immune system identifies and fights invading pathogens, while allowing non-pathogenic organisms to persist. Mechanisms of pathogen/non-pathogen discrimination are poorly understood, as is the contribution of human genetic variation in disease susceptibility. We describe here a new, IRF3-dependent signaling pathway that is critical for distinguishing pathogens from normal flora at the mucosal barrier. Following uropathogenic E. coli infection, Irf3(-/-) mice showed a pathogen-specific increase in acute mortality, bacterial burden, abscess formation and renal damage compared to wild type mice. TLR4 signaling was initiated after ceramide release from glycosphingolipid receptors, through TRAM, CREB, Fos and Jun phosphorylation and p38 MAPK-dependent mechanisms, resulting in nuclear translocation of IRF3 and activation of IRF3/IFNβ-dependent antibacterial effector mechanisms. This TLR4/IRF3 pathway of pathogen discrimination was activated by ceramide and by P-fimbriated E. coli, which use ceramide-anchored glycosphingolipid receptors. Relevance of this pathway for human disease was supported by polymorphic IRF3 promoter sequences, differing between children with severe, symptomatic kidney infection and children who were asymptomatic bacterial carriers. IRF3 promoter activity was reduced by the disease-associated genotype, consistent with the pathology in Irf3(-/-) mice. Host susceptibility to common infections like UTI may thus be strongly influenced by single gene modifications affecting the innate immune response. 相似文献
159.
Joëlle V. F. Coumans Pierre D. J. Moens Anne Poljak Samiya Al‐Jaaidi Lily Pereg Mark J. Raftery 《Proteomics》2010,10(8):1573-1591
Thielaviopsis basicola is a hemibiotroph fungus that causes black root rot disease in diverse plants with significant impact on cotton production in Australia. To elucidate how T. basicola growth and proteome are influenced by interactions with natural sources, this fungus was cultured in the presence of root extracts from non‐host (wheat, hairy vetch) and susceptible host (cotton, lupin) plants. We found that T. basicola growth was significantly favored in the presence of host extracts, while hierarchical clustering analysis of 2‐DE protein profiles of T. basicola showed plant species had a larger effect on the proteome than host/non‐host status. Analysis by LC‐MS/MS of unique and differentially expressed spots and identification using cross‐species similarity searching and de novo sequencing allowed successful identification of 41 spots. These proteins were principally involved in primary metabolism with smaller numbers implicated in other diverse functions. Identification of several “morpho” proteins suggested morphological differences that were further microscopically investigated. Identification of several highly expressed spots suggested that vitamin B6 is important in the T. basicola response to components present in hairy vetch extract, and finally, three spots, induced in the presence of lupin extract, may correspond to malic enzyme and be involved in lipid accumulation. 相似文献
160.
Prof. Dr. Andreas Bürkert Sulaiman Al Khanjari Nadiya A. Al‐Saady Edmond De Langhe Dirk Hölscher Jens Gebauer Stephan Behrendt Stefan Happe Katja Brinkmann Eva Schlecht 《当今生物学》2010,40(5):334-341
Until recently little was known about the crop diversity in the Sultanate of Oman, situated at the NE tip of the Arabian Peninsula. Interdisciplinary research in the often millenia‐old oases provide evidence for their role as reservoirs for plant genetic resources of ancient varieties of wheat and banana. Two newly discovered banana clones show a highly efficient biochemical defense mechanisms against some of the most devastating pests and diseases of banana. If these mechanisms can be properly understood and exploited in breeding programs, may have major impact on the commercial production of edible banana. 相似文献