bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reticulocyte hemoglobin content
Authors: Mast Alan E. , Blinder Morey A. , Dietzen Dennis J. 
Published: November 2007

AbstractUnder normal conditions, reticulocytes are the youngest erythrocytes released from the bone marrow into circulating blood. They mature for 1–3 days within the bone marrow and circulate for 1–2 days before becoming mature erythrocytes. Measurement of cellular hemoglobin concentration has long been reported by automated hematology analyzers as one of the red blood cell indices. The reticulocyte hemoglobin content (CHr or Ret‐He) provides an indirect measure of the functional iron available for new red blood cell production over the previous 3–4 days. Measurement of reticulocyte hemoglobin content in peripheral blood samples is useful for diagnosis of iron deficiency in adults (Mast et al., Blood 2002;99:1489–1491) and children (Brugnara et al., JAMA 1999;281:2225–2230; Ullrich et al., JAMA 2005;294:924–930; Bakr and Sarette, Eur J Pediatr 2006;165:442–445). It provides an early measure of the response to iron therapy increasing within 2–4 days of the initiation of intravenous iron therapy (Brugnara et al., Blood 1994;83:3100–3101). Sequential measurements of reticulocyte hemoglobin content in patients with iron deficiency anemia provide a rapid means for assessing the erythropoietic response to iron replacement therapy (Brugnara et al., Blood 1994;83:3100–3101). It is also an early indicator or iron‐restricted erythropoiesis in patients receiving erythropoietin therapy (Fishbane et al., Kidney Int 1997;52:217–222; Fishbane et al., Kidney Int 2001;60:2406–2411; Mittman et al., Am J Kidney Dis 1997;30:912–922; Tsuchiya et al., Clin Nephrol 2003;59:115–123; Chuang et al., Nephrol Dial Transplant 2003;18:370–377). Thus, reticulocyte hemoglobin content is a recent addition to an expanding list of biomarkers that can be used to differentiate iron deficiency from other causes of anemia. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
A phenotype for genetic studies of successful cognitive aging*
Authors: Silverman Jeremy M. , Schnaider‐Beeri Michal , Grossman Hillel T. , Schmeidler James , Wang Joy Y. , Lally Rachel C. 
Published: November 2007

AbstractSurvival from Alzheimer's disease (AD) and other dementias into late old age may be a useful phenotype for genetic studies of successful cognitive aging. To support molecular genetics studies for successful cognitive aging, we conducted a two‐stage study to determine an optimal age phenotype for successful cognitive aging. First, risk of AD was evaluated, through informant interviews, in 4,794 parents and siblings of 976 elderly nondemented probands who were divided into three different proband age groups: those aged 60–74, 75–89, and 90+. Relatives of probands aged 90+ had a significantly lower risk than the relatives of the other two proband groups. Second, this sample was combined with an earlier sample (combined nondemented elderly probands: n = 2,025; relatives: n = 10,506), and a series of proband age groups (i.e., 75–79, 80–84, 85–89, 90+) were used to determine which optimally identifies a group of relatives with low AD risk. Using the relatives of the nondemented proband aged 60–74 as the reference group, there were reductions in cumulative risk among relatives of probands aged 85–89 and 90+, but only the latter group also showed significant reductions to the relatives of probands aged 75–79, 80–84, and 85–89. This pattern of results varied little by sex. Finally, cumulative AD risk curves were similar between relatives of probands aged 90–94 and 95+. These results suggest that age 90 is an optimal age threshold to use for both men and women in genetic studies seeking to identify genes associated with successful cognitive aging. © 2007 Wiley‐Liss, Inc.
In vitro effects of methylmercury on ascidian (Styela plicata) immunocyte responses
Authors: Cammarata M. , Parisi M.G. , Benenati G. , Arizza V. , Cillari T. , Piazzese D. , Gianguzza A. , Vazzana M. , Vizzini A. , Parrinello N. 
Published: November 2007

AbstractThis study shows that high methylmercury concentrations are cytotoxic for Styela plicata hemocytes, whereas sublethal concentrations affect immunocyte responses. Moreover, hemocytes exposed to the xenobiotic present a significantly enhanced phenoloxidase activity as revealed in the hemocyte lysate supernatant compared with the control. Although the cytotoxic activity of S. plicata hemocytes toward rabbit erythrocytes is a PO‐dependent cell‐target reaction due to quinone products, it was significantly decreased by suitable methylmercury concentrations in the medium. The same xenobiotic concentrations decreased the hemocyte phagocytic activity toward yeast. In both the responses cell‐target contacts could be affected by methylmercury, whereas the releasing capacity appeared to be unchanged, as indicated by hemocyte PO‐release in the medium. Finally, changes in hemocyte shape and spreading capacity were shown. On the basis of the present results, Styela plicata hemocyte responses could be an additional immunotoxicology test using a microplate method that reveals cell morphological changes and spreading capacity. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis, structural characterization and catalytic activities of dicopper(II) complexes derived from tridentate pyrazole‐based N2O ligands
Authors: Zhang Guo‐Fang , Zhou Qiu‐Ping , Dou Yin‐Li , Yin Mai‐Hua , Wang Yao 
Published: November 2007

AbstractA group of a diverse family of dinuclear copper(II) complexes derived from pyrazole‐containing tridentate N2O ligands, 1,3‐bis(3,5‐dimethylpyrazol‐1‐yl)propan‐2‐ol (Hdmpzpo), 1,3‐bis(3‐phenyl‐5‐methyl pyrazol‐1‐yl)propan‐2‐ol (Hpmpzpo) and 1,3‐bis(3‐cumyl‐5‐methylpyrazol‐1‐yl)propan‐2‐ol (Hcmpzpo), were synthesized and characterized by elemental analysis, IR spectroscopy and three of them also by single‐crystal X‐ray diffraction. Three complexes, [Cu2(pmpzpo)2](NO3)2·2CH3OH (3·2CH3OH), [Cu2(pmpzpo)2](ClO4)2 (4) and [Cu2(cmpzpo)2](ClO4)2·2DMF (7·2DMF), each exhibits a dimeric structure with a inversion center being located between the two copper atoms. The metal ion is coordinated in a distorted square planar environment by two pyrazole nitrogen atoms and two bridging alkoxo oxygen atoms. Both complexes 1·CH3OH·H2O and 3·2CH3OH were investigated in anaerobic conditions for the catalytic oxidation of 3,5‐di‐tert‐butylcatechol (3,5‐DTBC) to the corresponding quinone (3,5‐DTBQ), for modeling the functional properties of catechol oxidase. Copyright © 2007 John Wiley & Sons, Ltd.
Electromagnetic fields alter the expression of estrogen receptor cofactors in breast cancer cells
Authors: Girgert Rainer , Gründker Carsten , Emons Günter , Hanf Volker 
Published: November 2007

AbstractBreast cancer is the most common malignancy of women in Western societies. The increasing exposure to electromagnetic fields has been suspected to contribute to the rising incidence of breast cancer in industrialized countries. The majority of breast tumors is treated with the partial antiestrogen tamoxifen. Most tumors become resistant to tamoxifen in the course of treatment resulting in treatment failure. Electromagnetic fields reduce the efficacy of tamoxifen similar to tamoxifen resistance. In this study we investigated the mechanism by which electromagnetic fields influence the sensitivity to tamoxifen. In cells exposed to 1.2 µT of a 50 Hz electromagnetic field gene expression of cofactors of the estrogen receptors was compared to sham exposed cells. Using a gene array technology several cofactors were found to be differentially expressed. The expression of the coactivators, SRC‐1 and AIB1, and of two corepressors, N‐Cor and SMRT, was quantified by RT‐PCR. Both coactivators were expressed more strongly in the exposed cells while the expression of two corepressors decreased. The RNA analysis was confirmed by Western blots. The contradirectional changes in gene expression of coactivators and corepressors by electromagnetic fields results in a lower sensitivity to tamoxifen. Electromagnetic fields may contribute to the induction of tamoxifen resistance in vivo. Bioelectromagnetics 29:169–176, 2008. © 2007 Wiley‐Liss, Inc.
Computational pore network modeling of the influence of biofilm permeability on bioclogging in porous media
Authors: Thullner Martin , Baveye Philippe 
Published: November 2007

AbstractFor many years, controversy has surrounded the use of biofilm models to describe the distribution of microbial biomass in natural or artificial porous media. This use is often advocated on the basis of the relative mathematical simplicity of the biofilm concept, and of the widespread availability of analytical solutions or numerical implementations. However, microscopic observations consistently point to a patchy, rather than homogeneous, distribution of microorganisms at the pore scale in many porous media of interest, even under conditions of severe bioclogging. Also, bioclogging models involving biofilms tend to underpredict the extent of permeability reductions in all be the coarse‐textured materials. In this context, computer simulations described in the present article show that some of the limitations of biofilm models to describe the bioclogging of porous media are linked to the common constitutive assumption that biofilms are impermeable, that is, that nutrient transport occurs through the biofilms only by molecular diffusion. When this restriction is alleviated and liquid flow is allowed in the biofilms, the level of bioclogging achievable by a given biomass is very significantly increased and is comparable to that observed in experiments. In addition, the distribution of microorganisms becomes patchy and exhibits a self‐organized periodic pattern with pores either entirely filled with biomass or without any biomass at all, again similar to published microscopic observations. These results suggest that biofilm models should not be ruled out a priori for the quantitative description of bioclogging in porous media, as long as biofilms are allowed to be permeable. Biotechnol. Bioeng. 2008;99: 1337–1351. © 2007 Wiley Periodicals, Inc.
Quantitative analysis of virus‐like particle size and distribution by field‐flow fractionation
Authors: Chuan Yap P. , Fan Yuan Y. , Lua Linda , Middelberg Anton P.J. 
Published: November 2007

AbstractAsymmetric flow field‐flow fractionation (AFFFF) coupled with multiple‐angle light scattering (MALS) is a powerful technique showing potential for the analysis of pharmaceutically‐relevant virus‐like particles (VLPs). A lack of published methods, and concerns that membrane adsorption during sample fractionation may cause sample aggregation, have limited widespread acceptance. Here we report a reliable optimized method for VLP analysis using AFFFF‐MALS, and benchmark it against dynamic light scattering (DLS) and transmission electron microscopy (TEM). By comparing chemically identical VLPs having very different quaternary structure, sourced from both bacteria and insect cells, we show that optimized AFFFF analysis does not cause significant aggregation, and that accurate size and distribution information can be obtained for heterogeneous samples in a way not possible with TEM and DLS. Optimized AFFFF thus provides a quantitative way to monitor batch consistency for new vaccine products, and rapidly provides unique information on the whole population of particles within a sample. Biotechnol. Bioeng. 2008;99: 1425–1433. © 2007 Wiley Periodicals, Inc.
Evaluation of microfluidics reactor technology on the kinetics of virus inactivation
Authors: Bailey Mark R. , Chen Dayue , Emery Warren R. , Lambooy Peter K. , Nolting Juliana , Quertinmont Michelle T. , Shamlou Parviz A. 
Published: November 2007

AbstractMammalian cell lines constitute an important part in the manufacture of therapeutic proteins. However, their susceptibility to virus contamination is a potential risk to patient safety and productivity, and has led to the development of a repertoire of virus inactivation techniques. From a process development viewpoint, the challenge is to demonstrate the required log reduction in virus content without a significant loss in product titer or quality. The balance between the two is dictated by the kinetics of virus inactivation and protein degradation, both of which are critically affected by process parameters. In this study we describe a commercially available microchannel reactor (MCR) and demonstrate how it can be used to evaluate the impact of temperature on the kinetics of virus inactivation and protein product degradation. Virus spiking experiments are reported using Xenotropic Murine Leukemia Virus and REOvirus, into buffers in the absence and presence of a therapeutic protein currently under development at Lilly. The results demonstrate that the MCR is an ideal platform for evaluation of fast reactive systems and reactions that are particularly sensitive to small changes to process conditions. These conditions include heat inactivation of a virus in a mammalian cell culture process stream used in the manufacture of therapeutic proteins and antibodies. Biotechnol. Bioeng. 2008;99: 1384–1391. © 2007 Wiley Periodicals, Inc.
Escherichia coli‐based cell‐free synthesis of virus‐like particles
Authors: Bundy Bradley C. , Franciszkowicz Marc J. , Swartz James R. 
Published: November 2007

AbstractVirus‐like particles (VLP) have received considerable attention for vaccine, drug delivery, gene therapy and material science applications. Although the number of unique VLP and their applications are rapidly growing, the positive impact of VLP applications is limited by the current diverse, expensive, and typically low‐yielding production technologies available. These technologies, when scaled, often result in structurally and compositionally inconsistent products. We present Escherichia coli‐based cell‐free protein synthesis as a production technology to overcome many of the limitations of current VLP production processes. Using this technique, the MS2 bacteriophage coat protein VLP was produced at a yield 14 times the best published production yield. Also, a C‐terminally truncated Hepatitis B core protein VLP was produced at similarly high yields (6 × 1013 VLP/mL). These VLP were found to have comparable characteristics to those produced in vivo. The scalability of this technology was tested without loss in production yields. To our knowledge, this is the first time a prokaryote‐based in vitro transcription/translation system has generated a virus‐like particle. Biotechnol. Bioeng. 2008;100: 28–37. Biotechnol. Bioeng. 2008;100: 28–37. © 2007 Wiley Periodicals, Inc.
Role of subsite +1 residues in pH dependence and catalytic activity of the glycoside hydrolase family 1 β‐glucosidase BGL1A from the basidiomycete Phanerochaete chrysosporium
Authors: Tsukada Takeshi , Igarashi Kiyohiko , Fushinobu Shinya , Samejima Masahiro 
Published: November 2007

AbstractThe basidiomycete Phanerochaete chrysosporium produces two glycoside hydrolase family 1 intracellular β‐glucosidases, BGL1A and BGL1B, during the course of cellulose degradation. In order to clarify the catalytic difference between two enzymes, in spite of their high similarity in amino acid sequences (65%), five amino acids around the catalytic site of BGL1A were individually mutated to those of BGL1B (V173C, M177L, D229N, H231D, and K253A), and the effects of the mutations on cellobiose hydrolysis were evaluated. When the kinetic parameters (Km and kcat) were compared at the optimum pH for the wild‐type enzyme, the kinetic efficiency was decreased in the cases of D229N, H231D, and K253A, but not V173C or M177L. The pH dependence of cellobiose hydrolysis showed a significantly more acidic pH profile for the D229N mutant, compared with the wild‐type enzyme. Since D229 is located between K253 and the putative acid/base catalyst E170, we prepared the double mutant D229N/K253A, and found that its hydrolytic activity at neutral pH was restored to that of the wild‐type enzyme. Our results indicate that the interaction between D229 and K253 is critical for the pH dependence and catalytic activity of BGL1A. Biotechnol. Bioeng. 2008;99: 1295–1302. © 2007 Wiley Periodicals, Inc.
High‐yield anthocyanin biosynthesis in engineeredEscherichia coli
Authors: Yan Yajun , Li Zhen , Koffas Mattheos A.G. 
Published: November 2007

AbstractAnthocyanins are red, purple, or blue plant water‐soluble pigments. In the past two decades, anthocyanins have received extensive studies for their anti‐oxidative, anti‐inflammatory, anti‐cancer, anti‐obesity, anti‐diabetic, and cardioprotective properties. In the present study, anthocyanin biosynthetic enzymes from different plant species were characterized and employed for pathway construction leading from inexpensive precursors such as flavanones and flavan‐3‐ols to anthocyanins inEscherichia coli. The recombinantE. colicells successfully achieved milligram level production of two anthocyanins, pelargonidin 3‐O‐glucoside (0.98 mg/L) and cyanidin 3‐O‐gluside (2.07 mg/L) from their respective flavanone precursors naringenin and eriodictyol. Cyanidin 3‐O‐glucoside was produced at even higher yields (16.1 mg/L) from its flavan‐3‐ol, (+)‐catechin precursor. Further studies demonstrated that availability of the glucosyl donor, UDP‐glucose, was the key metabolic limitation, while product instability at normal pH was also identified as a barrier for production improvement. Therefore, various optimization strategies were employed for enhancing the homogenous synthesis of UDP‐glucose in the host cells while at the same time stabilizing the final anthocyanin product. Such optimizations included culture medium pH adjustment, the creation of fusion proteins and the rational manipulation ofE. colimetabolic network for improving the intracellular UDP‐glucose metabolic pool. As a result, production of pelargonidin 3‐O‐glucoside at 78.9 mg/L and cyanidin 3‐O‐glucoside at 70.7 mg/L was achieved from their precursor flavan‐3‐ols without supplementation with extracellular UDP‐glucose. These results demonstrate the efficient production of the core anthocyanins for the first time and open the possibility for their commercialization for pharmaceutical and nutraceutical applications. Biotechnol. Bioeng. 2008;100: 126–140. © 2007 Wiley Periodicals, Inc.
Optimization of spray‐drying conditions for the large‐scale preparation of Bacillus thuringiensis var. israelensis after downstream processing
Authors: Prabakaran G. , Hoti S.L. 
Published: November 2007

AbstractReduction of water activity in the formulations of mosquito biocontrol agent, Bacillus thuringiensis var. israelensis is very important for long term and successful storage. A protocol for spray drying of B. thuringiensis var. israelensis was developed through optimizing parameters such as inlet temperature and atomization type. A indigenous isolate of B. thuringiensis var. israelensis (VCRC B‐17) was dried by freeze and spray drying methods and the moisture content and mosquito larvicidal activity of materials produced by the two methods were compared. The larvicidal activity was checked against early fourth instars Aedes aegypti larvae. Results showed that the freeze‐dried powders retained the larvicidal activity fairly well. The spray‐dried powder moderately lost its larvicidal activity at different inlet temperatures. Between the two types of atomization, centrifugal atomization retained more activity than the nozzle type atomization. Optimum inlet temperature for both centrifugal and nozzle atomization was 160°C. Keeping the outlet temperature constant at 70°C the moisture contents for the spray‐dried powders through centrifugal atomization and freeze‐dried powders were 10.23% and 11.80%, respectively. The LC50 values for the spray‐dried and freeze‐dried powders were 17.42 and 16.18 ng/mL, respectively. Spore count of materials before drying was 3 × 1010 cfu/mL and after spray drying through nozzle and centrifugal atomization at inlet and outlet temperature of 160°C/70°C were 2.6 × 109 and 5.0 × 109 cfu/mL, respectively. Biotechnol. Bioeng. 2008;100: 103–107. © 2007 Wiley Periodicals, Inc.
Reporter gene assay against lipophilic chemicals based on site‐specific genomic recombination of a nuclear receptor gene, its response element, and a luciferase reporter gene within a stable HeLa cell line
Authors: Mori Tetsushi , Saito Fumiyo , Yoshino Tomoko , Takeyama Haruko , Matsunaga Tadashi 
Published: November 2007

AbstractGenomic recombination was performed in a genetically modified stable HeLa cell line, HeLa55, using a uniquely designed donor vector harboring an exchange cassette comprised of the human glucocorticoid receptor (hGR) gene, its response element, and a luciferase reporter gene, to generate stable hGRLuc clones. After screening for cassette insertion, the selected stable clone, hGRLuc‐7, showed high integration stability of the exchange cassette over 20 passages with significantly high luciferase activity and fold inductions of up to 40‐ to 50‐fold. In addition, the cells were evaluated with synthetic glucocorticoid, dexamethasone, and a reasonable EC50 value of approximately 2.3 × 10−9 M was obtained. Strong and weak agonists, non‐responsive chemicals, and hGR antagonists were also evaluated in which the stable hGRLuc‐7 clone showed both high sensitivity and selectivity. The technology presented in this work is simple and reproducible, and shows great potential for the future development of genetically modified stable cell systems which are applicable in both fundamental and application researches of nuclear receptors. Biotechnol. Bioeng. 2008;99: 1453–1461. © 2007 Wiley Periodicals, Inc.
Effect of shear on performance and microbial ecology of continuously stirred anaerobic digesters treating animal manure
Authors: Hoffmann Rebecca A. , Garcia Marcelo L. , Veskivar Mehul , Karim Khursheed , Al‐Dahhan Muthanna H. , Angenent Largus T. 
Published: November 2007

AbstractWe determined the effect of different mixing intensities on the performance, methanogenic population dynamics, and juxtaposition of syntrophic microbes in anaerobic digesters treating cow manure from a dairy farm. Computer automated radioactive particle tracking in conjunction with computational fluid dynamics was performed to quantify the shear levels locally. Four continuously stirred anaerobic digesters were operated at different mixing intensities of 1,500, 500, 250, and 50 revolutions per min (RPM) over a 260‐day period at a temperature of 34 ± 1°C. Animal manure at a volatile solids (VS) concentration of 50 g/L was fed into the digesters daily at five different organic loading rates between 0.6 and 3.5 g VS/L day. The different mixing intensities had no effect on the biogas production rates and yields at steady‐state conditions. A methane yield of 0.241 ± 0.007 L CH4/g VS fed was obtained by pooling the data of all four digesters during steady‐state periods. However, digester performance was affected negatively by mixing intensity during startup of the digesters, with lower biogas production rates and higher volatile fatty acids concentrations observed for the 1,500‐RPM digester. Despite similar methane production yields and rates, the acetoclastic methanogenic populations were different for the high‐ and low‐intensity mixed digesters with Methanosarcina spp. and Methanosaeta concilii as the predominant methanogens, respectively. For all four digesters, epifluorescence microscopy revealed decreasing microbial floc sizes beginning at week 4 and continuing through week 26 after which no microbial flocs remained. This decrease in size, and subsequent loss of microbial flocs did not, however, produce any long‐term upsets in digester performance. Biotechnol. Bioeng. 2008;100: 38–48. © 2007 Wiley Periodicals, Inc.