| 1. |
- Gabrielsson, Britt, 1957, et al.
(författare)
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Molecular characterization of a local sulfonylurea system in human adipose tissue.
- 2004
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Ingår i: Molecular and cellular biochemistry. - 0300-8177 .- 1573-4919. ; 258:1-2, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- ATP-sensitive potassium (KATP) channels are present in many cell types and link cellular metabolism to the membrane potential. These channels are heterooctamers composed of two subunits. The sulfonylurea receptor (SUR) subunits are targets for drugs that are inhibitors or openers of the KATP channels, while the inwardly rectifying K+ (Kir) subunits form the ion channel. Two different SUR genes (SUR1 and SUR2) and two different Kir6.x genes (Kir6.1 and Kir6.2) have been identified. In addition, isoforms of SUR2, SUR2A and SUR2B, have been described. We have previously performed expression profiling on pooled human adipose tissue and found high expression of SUR2. Others have reported expression of SUR1 in human adipocytes. The aim of this study was to characterize the expression of the sulfonylurea receptor complex components in human adipose tissue. RT-PCR analysis, verified by restriction enzyme digestions and DNA sequencing, showed that SUR2B, Kir6.1 and alpha-endosulfine, but not SUR1, SUR2A or Kir6.2, are expressed in human adipose tissue. Real-time RT-PCR showed that SUR2B was expressed at higher levels in subcutaneous compared with omental adipose tissue in paired biopsies obtained from seven obese men (p < 0.05). Analysis of tissue distribution showed that SUR2B expression in adipose tissue was lower than that in muscle, similar to that in heart and liver, while the expression in pancreas was lower. The effect of caloric restriction was tested in obese men (n = 10) treated with very low calorie diet for 16 weeks, followed by a gradual reintroduction of ordinary food for 2 weeks. Biopsies were taken at week 0, 8 and 18. There was no consistent effect of weight reduction on SUR2B or Kir6.1 expression. We conclude that the necessary components for a local sulfonylurea system are expressed in human adipose tissue and that the sulfonylurea receptor complex in this tissue is composed of SUR2B and Kir6.1. The expression of SUR2B was higher in subcutaneous compared with omental adipose tissue and was not affected by weight loss.
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| 2. |
- Sjöholm, Kajsa, 1971, et al.
(författare)
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A microarray search for genes predominantly expressed in human omental adipocytes: adipose tissue as a major production site of serum amyloid A.
- 2005
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Ingår i: Journal of Clinical Endocrinology & Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 90:4, s. 2233-9
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Tidskriftsartikel (refereegranskat)abstract
- To identify genes predominantly expressed in omental adipocytes, microarray expression profiles from 33 human tissues or cell types were analyzed, using an algorithm developed for identification of transcripts predominantly expressed in a certain tissue. Both known adipocyte-specific and more unexpected genes were among the 28 genes identified. To validate the approach, adipocyte expression of three of these genes, acute-phase serum amyloid A (A-SAA), aquaporin 7, and transport secretion protein-2.2, was compared with 17 other human tissues by real-time PCR. The unexpectedly high expression of A-SAA in adipocytes was further verified by Northern blot and immunohistochemistry. The liver, reported to be the main production site for A-SAA, displayed the second highest expression using microarray and real-time PCR. In obese subjects, adipose tissue mRNA and serum A-SAA levels were down-regulated during an 18-wk diet regime (P < 0.05 and P < 0.0001, respectively). A-SAA serum levels were highly correlated to adipose tissue mRNA levels (P < 0.001) and to the total (P < 0.0001) and sc (P < 0.0001) adipose tissue areas, as analyzed by computed tomography. We show that adipose tissue is a major expression site of A-SAA during the nonacute-phase reaction condition. This provides a direct link between adipose tissue mass and a marker for low-grade inflammation and cardiovascular risk.
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| 3. |
- Carlsson, Jenny, 1977-, et al.
(författare)
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An indirect competitive immunoassay for insulin autoantibodies based on surface plasmon resonance
- 2008
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Ingår i: Biosensors and Bioelectronics. - : Elsevier BV. - 0956-5663. ; 24:4, s. 876-881
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a sensitive and specific method based on surface plasmon resonance (SPR) for detection of insulin autoantibodies (IAA) in serum samples from individuals at high risk of developing type 1 diabetes (T1D). When measuring trace molecules in undiluted sera with label-free techniques like SPR, non-specific adsorption of matrix proteins to the sensor surface is often a problem, since it causes a signal that masks the analyte response. The developed method is an indirect competitive immunoassay designed to overcome these problems. Today, IAA is mainly measured in radio immunoassays (RIAs), which are time consuming and require radioactively labeled antigen. With our SPR-based immunoassay the overall assay time is reduced by a factor of >100 (4 days to 50 min), while sensitivity is maintained at a level comparable to that offered by RIA.
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| 4. |
- Carlsson, Jenny, 1977-, et al.
(författare)
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Biosensor discrimination of meat juice from various animals using a lectin panel and ellipsometry
- 2005
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670 .- 1873-4324. ; 547:2, s. 229-236
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Tidskriftsartikel (refereegranskat)abstract
- In this work, simple microcontact printed gold-wafers were used to make a lectin panel for investigation and discrimination of different meat juices from fresh meat of cattle, chicken, pig, cod, turkey and lamb. Seven different lectins were thus attached to gold surfaces using the streptavidin–biotin method. Lectins recognize and bind specifically to carbohydrate structures present on different proteins. The biorecognition was evaluated with null ellipsometry and the data obtained was related to an internal standard of lactoferrin. The data was evaluated with multivariate data analysis techniques to identify possible discrimination or grouping of data. Scanning ellipsometry was used for visualization of the binding pattern of the lectins and the meat juice proteins. The two-dimensional images obtained could be used to visualize the protein distribution, furthermore, to exclude anomalies. The results showed that the different meat juices from the six different species: cattle, chicken, pig, cod, turkey and lamb could be discriminated from each other. The results showed to be more repetitive for the mammalian meat juices. Using a simple model based on an artificial neuronal net, it was also possible to classify meat juices from the mammals investigated.
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| 5. |
- Carlsson, Jenny, 1977-, et al.
(författare)
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Detection of global glycosylation changes of serum proteins in type 1 diabetes using a lectin panel and multivariate data analysis
- 2008
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Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 76:2, s. 333-337
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Tidskriftsartikel (refereegranskat)abstract
- Global glycosylation changes of serum proteins in type 1 diabetic patients have in this paper been investigated based on the interaction of the saccharide moiety of serum proteins with different lectins. Lectins are proteins, which bind carbohydrates specifically and reversibly. Panels with lectins of various carbohydrate specificities were immobilized on gold surfaces. Sera from healthy individuals, newly diagnosed type 1 diabetes patients and type 1 diabetes patients having had the disease for 4–6 years, respectively, were applied to the lectin panel. The biorecognition was evaluated with null ellipsometry. Data obtained were related to an internal standard of lactoferrin. Multivariate data analysis (MVDA) techniques were used to analyze data. Principal component analysis showed that the lectin panel enabled discrimination between sera from the three different above-mentioned groups. Using an artificial neuronal net (ANN), it was possible to correctly categorize unknown serum samples into one of the three groups.
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| 6. |
- Carlsson, Jenny, 1977-, et al.
(författare)
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Determination of insulin autoantibodies using surface plasmon resonance: A screening study of newly diagnosed type 1 diabetes patients
- 2008
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- We have investigated the screening potential of a surface plasmon resonance (SPR)-based indirectcompetitive immunoassay for quantification of insulin autoantibodies (IAA) in sera from childrennewly diagnosed with type 1 diabetes (T1D), using a radioimmunoassay (RIA) as reference technique.The two methods agreed well with respect to sample classification of 54 sera from newly diagnosedT1D children and 32 reference sera from non-diabetic children. Interestingly, five samples from newlydiagnosed T1D patients classified as IAA-negative according to RIA were IAA-positive with the SPRbasedassay, suggesting that the SPR-based assay might provide a higher sensitivity than the referenceRIA. However, 14 percent of the analyzed samples (five samples from non-diabetics and seven fromnewly diagnosed T1D patients) gave rise to anomalously high and easily distinguishable responses withthe SPR-based method, precluding IAA-quantification. A considerable part of the paper is devoted to adiscussion of possible causes of these anomalous responses. They were not due to temporary changesin the status of the patients, such as infections at the time of sampling, and also not related tocomplement activation. It is speculated whether a plausible explanation should instead be sought in theexistence of anti-idiotypic antibodies to IAA.
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| 7. |
- Carlsson, Jenny, 1977-
(författare)
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Interaction Studies in Complex Fluids with Optical Biosensors
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis interactions in complex fluids, such as serum and meat juice, were analysed with optical biosensor techniques.Panels of lectins immobilised on gold surfaces were used for investigation of differences in protein glycosylation pattern in sera and meat juices between various species. The present panel was also used for investigation of global glycosylation changes of serum proteins in type 1 diabetes patients. Biorecognition was evaluated with null ellipsometry and scanning ellipsometry combined with multivariate data analysis techniques (MVDA). Principal component analysis (PCA) showed that the lectin panel enabled discrimination between sera from the different species as well as for the different meat juices. The results also indicate that there is a measurable global alteration in glycosylation pattern of serum proteins in type 1 diabetic patients compared to healthy subjects. Using an artificial neuronal net (ANN), it was also possible to correctly categorise unknown serum samples into their respective class or group. The analytical potential of combining information from lectin panels with multivariate data analysis was thereby demonstrated.Also, a sensitive and specific method based on surface plasmon resonance (SPR) for detection of insulin autoantibodies (IAA) in serum samples from individuals at high risk of developing type 1 diabetes (T1D) has been developed. When measuring trace molecules, such as autoantibodies, in undiluted sera with label-free techniques like SPR, non-specific adsorption of matrix proteins to the sensor surface is often a problem, since it causes a signal that masks the analyte response. The developed method is an indirect competitive immunoassay designed to overcome these problems. Today, IAA is mainly measured in radio immunoassays (RIAs), which are time consuming and require radioactively labelled antigen. With our SPR-based immunoassay the overall assay time is reduced by a factor of >100 (from 4 days to 50 min), while sensitivity is maintained at a level comparable to that offered by RIA. Finally, the assay was used in a screening study of newly diagnosed type 1 diabetes patients and non-diabetic subjects.
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| 8. |
- Carlsson, Jenny, 1977-, et al.
(författare)
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Investigation of sera from various species by using lectin affinity arrays and scanning ellipsometry
- 2005
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670 .- 1873-4324. ; 530:2, s. 167-171
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Tidskriftsartikel (refereegranskat)abstract
- Serum proteins of different species and of different human blood groups exhibit various protein glycosylation patterns. Sera from human, pig, sheep and guinea pig have been applied to a panel of eight different lectins immobilized on a gold wafer. The biorecognition has been evaluated with scanning ellipsometry and the two-dimensional matrices obtained have been treated with image analysis and MVDA for evaluation. The results showed a clear difference in protein binding pattern between the different species and thereby separation of the different sera could be made. Dendograms indicate that human and pig sera are the most related of the four different sera investigated.
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| 9. |
- Carlsson, Jenny, 1977-
(författare)
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Surface analytical methods and multivariate data analysis applied to lectin panels
- 2004
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis lectin panels on gold wafers were utilized to investigate sera from different mammals and meat juices from various species of animals. Lectins, which are a group of diverse, natural proteins recognize and bind to different carbohydrate structures present on the sera proteins and on the proteins in the different meat juices. The binding patterns from the relatively unspecific interactions between lectins and carbohydrate structures were evaluated with techniques based on ellipsometry. The resulting data was treated with multivariate data analysis (MVDA) techniques, especially principal component analysis (PCA), to identify separation or grouping of data.It was shown that lectin panels combined with ellipsometric techniques and MVDA could be used to separate sera from different mammals and also a possible relation between species could be seen. Meat juices from the different species evaluated were also possible to separate and using a simple model based on an artificial neuronal net, it was also possible to classify meat juices from the mammals investigated. In spite of its great analytical potential, not much work has yet been done utilizing MVDA together with bioanalytical methods. The results in this thesis however, show great potential for combining lectin panels with MVDA.This work, regarding lectin panels, was incorporated as a part of a EU-project, Nanocell. The aim of the Nanocell-project was to develop a biosensor consisting of a single biomolecule electrically interfaced to nanoelectrodes, which is sensed electronically/optically.
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| 10. |
- Henning, Petra, 1974, et al.
(författare)
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Adenovirus type 5 fiber knob domain has a critical role in fiber protein synthesis and encapsidation
- 2006
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Ingår i: JOURNAL OF GENERAL VIROLOGY. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 87, s. 3151-3160
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Tidskriftsartikel (refereegranskat)abstract
- Adenovirus serotype 5 (Ad5) vectors carrying knobless fibers designed to remove their natural tropism were found to have a lower fiber content than recombinant Ad5 with wild-type (WT) capsid, implying a role for the knob-coding sequence or/and the knob domain in fiber encapsidation. Experimental data using a variety of fiber gene constructs showed that the defect did not occur at the fiber mRNA level, but at the protein level. Knobless fiber proteins were found to be synthesized at a significant slower rate compared with knob-carrying fibers, and the trimerization process of knobless fibers paralleled their slow rate of synthesis. A recombinant Ad5 diploid for the fiber gene (referred to as Ad5/R7-ZZwt/E1 : WT-fiber) was constructed to analyse the possible rescue of the knobless low-fiber-content phenotype by co-expression of WT fiber. Ad5/R7-ZZwt/E1 : WT-fiber contained a knobless fiber gene in its natural location (L5) in the viral genome and an additional WT fiber gene in an ectopic position in E1. Knobless fiber was still synthesized at low levels compared with the co-expressed E1 : WT fiber and the recovery of the two fiber species in virus progeny reflected their respective amounts in the infected cells. Our results suggested that deletion of the fiber knob domain had a negative effect on the translation of the fiber mRNA and on the intracellular concentration of fiber protein. They also suggested that the knob control of fiber protein synthesis and encapsidation occurred as aciseffect, which was not modified by WT fiber protein providedin transby the same Ad5 genome.
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