| 1. |
- Aniansson Zdolsek, Helena, 1961-, et al.
(författare)
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Expression of the T–cell markers CD3, CD4 and CD8 in healthy and atopic Children during the first 18 months of life
- 1999
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Ingår i: International Archives of Allergy and Immunology. - : S. Karger AG. - 1018-2438 .- 1423-0097. ; 119:1, s. 6-12
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is little information available about the development of T–cell immunity in healthy and atopic children. We have studied prospectively the mean fluorescence intensity of the T–cell receptor complex–associated CD3, CD4 and CD8 in relation to atopic family history (AFH) and the development of atopic disease.Methods: Children with a defined AFH (n = 172) were followed from birth to 18 months and the cumulative history of atopic disease was recorded. Blood samples were obtained at birth and at 18 months, and in a subgroup of 78 children also at 3, 6 and 12 months. Multicolour flow cytometry was used to analyse pan T–cells (CD3+CD45+CD14–), T–helper–(CD3+CD4+) and T–cytotoxic–(CD3+CD8+) cells.Results: At 18 months, 31 children were atopic and 118 non–atopic. Children who developed atopic disease had a higher CD4 expression (mean fluorescence intensity, MFI) on CD4+CD3+ lymphocytes at birth and at 3 months, particularly as compared with non–atopic children without AFH. Furthermore, the CD3 expression on CD3+CD45+CD14– lymphocytes increased more slowly with age in children with double atopic heredity, as compared with children with no or only one atopic family member.Conclusions: The higher expression of the CD4 receptor in early infancy in children who developed atopic disease compared with non–atopics suggests a delayed expression in T–helper cells. Children with a strong AFH had a slower increase in the expression of CD3, indicating a delayed T–cell maturation.
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| 2. |
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| 3. |
- Diehl, Annika, et al.
(författare)
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Energy Efficiency in Cement Industry
- 1999
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Abstract in UndeterminedEconomic development that includes investments in infrastructure and buildings requires energy intensive basic materials such as steel and cement. The production capacity of these industries is also growing most rapidly in developing countries [WEC, 1995 #41]. Energy intensive industries typically account for a relatively small share of the value-added in industry but a relatively large share of industrial energy use and associated carbon-dioxide emissions. They are therefore likely to be the target of national and international efforts to reduce emissions, for example through mechanisms as devised in the protocols to the climate convention.The overall objective of this project is to improve our understanding of industrial energy use and efficiency in developing countries and in particular explore explanatory factors for success and failure in reaching high levels of efficiency. Large differences can be found when comparing industrial energy efficiency for specific industry branches across countries. Such comparisons may be misleading if differences in energy statistics and industrial product mix, quality or input materials are not accounted for. The work presented here is in part a contribution to the development of methodologies for international comparisons and an input to the International Network for Energy Demand Analysis hosted by the Energy Analysis Department at the Environmental Energy Technologies Division of the Lawrence Berkeley National Laboratory (LBNL).The first phase of the project which is reported on here focus on the cement industry and methodologies for international comparisons of energy efficiency in the cement industry. The cement industry was selected in part because it produces relatively homogeneous products, clinker and cement, albeit of various qualities, which should facilitate international comparisons. The analysis of different methods is primarily based on data for eight selected countries in the database hosted by LBNL.The results presented here serves as a background and starting point for more in-depth assessments of underlying factors for success and failure in energy efficiency in the cement industry. An analytical framework for systematically assessing relevant factors is proposed. In the next project phase, China has been selected as a case-study country due to its rapid growth in cement production, an interesting mix of small cement kilns in township and village enterprises and large modern cement plants, and its apparently high level of energy efficiency in large parts of the industry.
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| 4. |
- Gräslund, Torbjörn, et al.
(författare)
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Production of a Thermostable DNA Polymerase by Site-Specific Cleavage of a Heat-Eluted Affinity Fusion Protein
- 1997
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Ingår i: Protein Expression and Purification. - : Elsevier BV. - 1046-5928 .- 1096-0279. ; 9, s. 125-132
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Tidskriftsartikel (refereegranskat)abstract
- A novel strategy is described for bacterial expression and affinity purification of a recombinant truncated version of the heat-stable DNA polymerase I fromThermus aquaticus.The DNA polymerase ([Delta]Taq) was produced as a fusion to a serum albumin binding affinity handle (ABP) derived from streptococcal protein G. Based on the thermostability of the [Delta]TaqDNA polymerase, affinity-purified ABP-[Delta]Taqcould be heat-eluted from HSA columns by incubation at 85ï¿œC. To produce free [Delta]TaqDNA polymerase, efficient site-specific cleavage of the affinity tag was performed using a recombinant coxsackievirus 3C protease (3Cpro), also produced as an ABP affinity fusion. Thus, an integrated strategy could be devised where both the cleaved ABP affinity tag and the protease fusion could be recovered after site-specific cleavage using HSA-affinity chromatography. The flow-through fraction contained essentially pure [Delta]TaqDNA polymerase with full enzymatic activity.
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| 5. |
- Nilsson, Dag, et al.
(författare)
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Absorption of L-DOPA from the proximal small intestine studied in the rhesus monkey by positron emission tomography
- 1999
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Ingår i: European Journal of Pharmaceutical Sciences. - 0928-0987 .- 1879-0720. ; 7:3, s. 185-189
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Tidskriftsartikel (refereegranskat)abstract
- Positron emission tomography (PET) seems to be a valuable method for the understanding of intestinal absorption mechanisms, for simultaneous quantitation of absorption rate and distribution kinetics to the tissues of interest after oral drug delivery. PET was evaluated in three Rhesus monkeys for quantitation of the absorption rate from the gastrointestinal tract and the distribution kinetics into different organs. To obtain optimal standardized conditions for the measurement of absorption the drug was administered via a naso-duodenal catheter directly to the absorption site in the proximal small intestine. l-DOPA was used as study drug given in a suspension together with carbidopa and the radiomarker l-[beta-11C]DOPA. The l-DOPA suspension was given into the duodenum without and after administration of a suspension of six l-amino acids (120 mM) in order to investigate any interaction on the intestinal absorption and distribution of l-DOPA into the liver and brain tissue. Intestinal absorption was in general minor during the first study period and higher together with administered l-amino acids. The somewhat contradictory result with increased absorption when amino acids were present in the intestinal lumen, may be a consequence of increased intestinal motility initiated by the nutrient load.
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| 6. |
- Nilsson, Peter, et al.
(författare)
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Mutational scanning of PCR products by subtractive oligonucleotide hybridization analysis
- 1999
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Ingår i: BioTechniques. - : Future Science Ltd. - 0736-6205 .- 1940-9818. ; 26:2, s. 308-
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Tidskriftsartikel (refereegranskat)abstract
- Here, we describe a new approach for mutational scanning of PCR products through hybridization analysis between complementary oligonucleotides. Sets of overlapping probe oligonucleotides complementary to wild-type (WT) sequence are hybridized to microbead-immobilized PCR products under solution-like conditions. Mismatch-hybridization situations between a mutant sample and probe oligonucleotides result in higher remaining concentrations in solution of involved probe oligonucleotides. Post-hybridization supernatants are subsequently analyzed for their probe oligonucleotide compositions using surface plasmon resonance-based biosensor technology Relative remaining probe oligonucleotide concentrations are monitored in real-time through hybridization analysis between probe oligonucleotides and their corresponding sensor-chip immobilized complementary counterparts. This allows for the construction of composition diagrams revealing the existence and approximate location of a mutation within an investigated sample DNA sequence. Applied on PCR products derived from clinical samples of microdissected tumor biopsies, single mutations in exons 6 and 7 of the human p53 tumor-suppressor gene were successfully detected and approximately localized.
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| 7. |
- Nilsson, Peter, et al.
(författare)
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Quantitative Investigation of the Modular Primer Effect for DNA and Peptide Nucleic Acid Hexamers
- 1999
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Ingår i: Analytical Biochemistry. - : Elsevier BV. - 0003-2697 .- 1096-0309. ; 269:1, s. 155-161
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Tidskriftsartikel (refereegranskat)abstract
- The effect on oligonucleotide–template duplex stability upon cohybridization of adjacently annealing oligonucleotides, the modular primer effect, was studied with biosensor technology. DNA and peptide nucleic acid (PNA) hexamer modules and sensor chip-immobilized template DNA strands were designed for analysis of nick, overlap, and gap modular hybridization situations. The fast hybridization kinetics for such hexamer modules allowed for the determination of apparent duplex affinities from equilibrium responses. The results showed that the hybridizational stability of modular hexamer pairs is strongly dependent on the positioning, concentration, and inherent affinity of the adjacently annealing hexamer module. Up to 80-fold increases in apparent affinities could be observed for adjacent modular oligonucleotide pairs compared to affinities determined for single hexamer oligonucleotide hybridizations. Interestingly, also for coinjections of different module combinations where DNA hexamer modules were replaced by their PNA counterparts, a modular primer effect was observed. The introduction of a single base gap between two hexamer modules significantly reduced the stabilization effect, whereas a gap of two bases resulted in a complete loss of the effect. The results suggest that the described biosensor-based methodology should be useful for the selection of appropriate modules and working concentrations for use in different modular hybridization applications.
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| 8. |
- O'Meara, Deirdre, et al.
(författare)
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Capture of single-stranded DNA assisted by oligonucleotide modules
- 1998
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Ingår i: Analytical Biochemistry. - : Elsevier BV. - 0003-2697 .- 1096-0309. ; 255:2, s. 195-203
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Tidskriftsartikel (refereegranskat)abstract
- Real-time biospecific interaction analysis was employed to monitor direct capture of a hepatitis C virus (HCV) derived polymerase chain reaction (PCR) product by nucleic acid hybridization. Different formats for hybridization were used to study the interaction between a single-stranded HCV PCR product and capture oligonucleotides immobilized on a sensor chip via streptavidin-biotin chemistry. By employing a prehybridization step in solution with nonbiotin oligonucleotides complementary to the single-stranded target and adjacent to the immobilized probe, a significant capture was achieved in comparison to the low capture efficiency obtained using single immobilized probes (9-36 mer). High capture efficiencies were also observed when shorter immobilized probes were used in combination with strings of adjacently positioned prehybridized probes (i.e., modules). Interestingly, the introduction of single nucleotide gaps between prehybridized and/or immobilized probes dramatically reduced the capture efficiency. These results suggest that flexible systems for capture could be designed from libraries of short oligonucleotides (9 mers) used in module fashion, taking advantage of stacking interactions between the oligonucleotides. The potential applications of such oligonucleotide-assisted capture systems are discussed.
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| 9. |
- Schelén, Olov, et al.
(författare)
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Performance of QoS agents for provisioning network resources
- 1999
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Ingår i: 1999 Seventh International Workshop on Quality of Service. - Piscataway, NJ : IEEE Communications Society. - 0780356713 ; , s. 17-26
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Konferensbidrag (refereegranskat)abstract
- We have designed an agent-based architecture for quantitative service provisioning in differentiated services capable networks. For each link-state routing domain in the network there is a topology-aware QoS agent (also known as a bandwidth broker) responsible for admission control. The architecture provides resource reservations for aggregated virtual leased lines between network domains. In this paper, we present performance measurements for resource provisioning in a prototype QoS agent. This includes an evaluation of two data structures for advance reservations and accompanying algorithms. We also compare the cost for on-demand route computations with pre-computation of routes. The objective in this paper is to evaluate the performance of end-to-end admission control within a single link-state routing domain. In a domain with 15 routers, 28 transition networks and 64 stub networks, our prototype performs approximately 25000 end-to-end admission decisions per second. The results show that an ordinary PC can be used for running a QoS agent that performs path-sensitive admission control and maintains per link resource reservations in a link-state routing domain.
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