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排序方式: 共有272条查询结果,搜索用时 15 毫秒
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Allyson Tucker Dilks Joanne Gilchrist Yik Lam Nathan Nicholes Brad Stanley 《Biotechnology progress》2023,39(4):e3351
No-salt flowthrough hydrophobic interaction chromatography (HIC) has been shown to effectively remove process and product-related impurities from bioprocess streams. In this publication, a panel of six antibodies has been used to demonstrate operating principles for the application of no-salt flowthrough HIC in antibody purification processes. The results indicate that no-salt flowthrough HIC provides robust aggregate clearance across operating conditions including flow rate, and variations in resin ligand density. Additionally, HMW reduction has an optimal pH range relative to the isoelectric point of each molecule and high molecular weight (HMW) reduction can be improved by altering the total protein load and/or HMW concentration to drive binding of high molecular weight species to the resin. 相似文献
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Michael J. Renner Allyson J. Bennett Michele L. Ford Peter J. Pierre 《Primates; journal of primatology》1992,33(3):315-327
Investigatory behavior with novel, inanimate objects by two groups of four juvenile greater bushbabies (Otolemur garnettii) was examined in the laboratory. Substantial investigatory behavior was shown by all subjects. In the first study, subjects
showed interest in a wide variety of nonfood stimulus objects. In the second, subjects displayed sustained interest in and
investigation of non-food stimulus objects over three sessions. Bushbabies showed preferences for larger, more manipulable
objects and variations in total contact over days. Individual differences were observed in the duration and types of contact
with objects. These observations contradict earlier reports that prosimians show little interest in inanimate, non-food objects. 相似文献
5.
Jonathan H. Epstein Michelle L. Baker Carlos Zambrana-Torrelio Deborah Middleton Jennifer A. Barr Edward DuBovi Victoria Boyd Brian Pope Shawn Todd Gary Crameri Allyson Walsh Katey Pelican Mark D. Fielder Angela J. Davies Lin-Fa Wang Peter Daszak 《PloS one》2013,8(6)
Old World frugivorous bats have been identified as natural hosts for emerging zoonotic viruses of significant public health concern, including henipaviruses (Nipah and Hendra virus), Ebola virus, and Marburg virus. Epidemiological studies of these viruses in bats often utilize serology to describe viral dynamics, with particular attention paid to juveniles, whose birth increases the overall susceptibility of the population to a viral outbreak once maternal immunity wanes. However, little is understood about bat immunology, including the duration of maternal antibodies in neonates. Understanding duration of maternally derived immunity is critical for characterizing viral dynamics in bat populations, which may help assess the risk of spillover to humans. We conducted two separate studies of pregnant Pteropus bat species and their offspring to measure the half-life and duration of antibodies to 1) canine distemper virus antigen in vaccinated captive Pteropus hypomelanus; and 2) Hendra virus in wild-caught, naturally infected Pteropus alecto. Both of these pteropid bat species are known reservoirs for henipaviruses. We found that in both species, antibodies were transferred from dam to pup. In P. hypomelanus pups, titers against CDV waned over a mean period of 228.6 days (95% CI: 185.4–271.8) and had a mean terminal phase half-life of 96.0 days (CI 95%: 30.7–299.7). In P. alecto pups, antibodies waned over 255.13 days (95% CI: 221.0–289.3) and had a mean terminal phase half-life of 52.24 days (CI 95%: 33.76–80.83). Each species showed a duration of transferred maternal immunity of between 7.5 and 8.5 months, which was longer than has been previously estimated. These data will allow for more accurate interpretation of age-related Henipavirus serological data collected from wild pteropid bats. 相似文献
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Caitlin E. VanOrsdel Shantanu Bhatt Rondine J. Allen Evan P. Brenner Jessica J. Hobson Aqsa Jamil Brittany M. Haynes Allyson M. Genson Matthew R. Hemm 《Journal of bacteriology》2013,195(16):3640-3650
Cytochrome bd oxidase operons from more than 50 species of bacteria contain a short gene encoding a small protein that ranges from ∼30 to 50 amino acids and is predicted to localize to the cell membrane. Although cytochrome bd oxidases have been studied for more than 70 years, little is known about the role of this small protein, denoted CydX, in oxidase activity. Here we report that Escherichia coli mutants lacking CydX exhibit phenotypes associated with reduced oxidase activity. In addition, cell membrane extracts from ΔcydX mutant strains have reduced oxidase activity in vitro. Consistent with data showing that CydX is required for cytochrome bd oxidase activity, copurification experiments indicate that CydX interacts with the CydAB cytochrome bd oxidase complex. Together, these data support the hypothesis that CydX is a subunit of the CydAB cytochrome bd oxidase complex that is required for complex activity. The results of mutation analysis of CydX suggest that few individual amino acids in the small protein are essential for function, at least in the context of protein overexpression. In addition, the results of analysis of the paralogous small transmembrane protein AppX show that the two proteins could have some overlapping functionality in the cell and that both have the potential to interact with the CydAB complex. 相似文献
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Dr. Emily B. Schirmer Kathryn Golden Jin Xu Jesse Milling Alec Murillo Patricia Lowden SriHariRaju Mulagapati Jinzhao Hou Joseph T. Kovalchin Allyson Masci Kathryn Collins Gregory Zarbis-Papastoitsis 《Biotechnology journal》2013,8(8):946-956
Through a parallel approach of tracking product quality through fermentation and purification development, a robust process was designed to reduce the levels of product-related species. Three biochemically similar product-related species were identified as byproducts of host-cell enzymatic activity. To modulate intracellular proteolytic activity, key fermentation parameters (temperature, pH, trace metals, EDTA levels, and carbon source) were evaluated through bioreactor optimization, while balancing negative effects on growth, productivity, and oxygen demand. The purification process was based on three non-affinity steps and resolved product-related species by exploiting small charge differences. Using statistical design of experiments for elution conditions, a high-resolution cation exchange capture column was optimized for resolution and recovery. Further reduction of product-related species was achieved by evaluating a matrix of conditions for a ceramic hydroxyapatite column. The optimized fermentation process was transferred from the 2-L laboratory scale to the 100-L pilot scale and the purification process was scaled accordingly to process the fermentation harvest. The laboratory- and pilot-scale processes resulted in similar process recoveries of 60 and 65%, respectively, and in a product that was of equal quality and purity to that of small-scale development preparations. The parallel approach for up- and downstream development was paramount in achieving a robust and scalable clinical process. 相似文献
9.
Thomas C. Darton Claire Jones Christoph J. Blohmke Claire S. Waddington Liqing Zhou Anna Peters Kathryn Haworth Rebecca Sie Christopher A. Green Catherine A. Jeppesen Maria Moore Ben A. V. Thompson Tessa John Robert A. Kingsley Ly-Mee Yu Merryn Voysey Zoe Hindle Stephen Lockhart Marcelo B. Sztein Gordon Dougan Brian Angus Myron M. Levine Andrew J. Pollard 《PLoS neglected tropical diseases》2016,10(8)
BackgroundTyphoid persists as a major cause of global morbidity. While several licensed vaccines to prevent typhoid are available, they are of only moderate efficacy and unsuitable for use in children less than two years of age. Development of new efficacious vaccines is complicated by the human host-restriction of Salmonella enterica serovar Typhi (S. Typhi) and lack of clear correlates of protection. In this study, we aimed to evaluate the protective efficacy of a single dose of the oral vaccine candidate, M01ZH09, in susceptible volunteers by direct typhoid challenge.ConclusionsDespite successfully demonstrating the use of a human challenge study to directly evaluate vaccine efficacy, a single-dose M01ZH09 failed to demonstrate significant protection after challenge with virulent Salmonella Typhi in this model. Anti-Vi antibody detected prior to vaccination played a major role in outcome after challenge.
Trial registration
ClinicalTrials.gov () and EudraCT (number 2011-000381-35). NCT01405521相似文献10.
The Circadian Clock Gene Circuit Controls Protein and Phosphoprotein Rhythms in Arabidopsis thaliana