| 1. |
- Lundberg, Peter, et al.
(author)
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Permeabilization of Plant Cells: 31P NMR Studies of the Permeability of the Tonoplast
- 1986
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In: Plant Cell Reports. - : Springer. - 0721-7714 .- 1432-203X. ; 5, s. 13-16
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Journal article (peer-reviewed)abstract
- A suspension culture of Catharanthus roseus has been used to study the permeability of cell membranes after treatment with various concentrations of a permeabilizing agent (DMSO). The uptake and release (after permeabilization) of inorganic phosphate (Pi) by cells have been investigated by 32P radiotracer and non-invasive phosphorus-31 NMR experiments. These studies have demonstrated that measurements of the Pi-efflux from plant cells provide a reliable measure of the permeability of the tonoplast.
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| 2. |
- Nilsson, Kjell, et al.
(author)
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A General Method for the Immobilization of Cells with Preserved Viability
- 1983
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In: Applied Microbiology and Biotechnology. ; 17, s. 319-326
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Journal article (peer-reviewed)abstract
- Microbial, algal, plant and animal cells have been immobilized, with preserved viability, by entrapment in various matrices according to a new bead polymerization technique. The cell polymer/monomer mixture is kept suspended in a hydrophobic phase such as soy, paraffin, or silicon oil, tri-n-butylphosphate, or dibutyphtalate, which is compatible with the cells. The various monomers or polymers tested include agarose, agar, carrageenan, alginate, fibrin, and polyacrylamide. Furthermore, by adjustment of the stirring speed of the suspension, beads of desired diameter can easily be obtained. The entrapped cells are fully viable and biosynthetically active.
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| 3. |
- Wirth, Michael, 1956, et al.
(author)
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Interactions between DNA and mono-, bis-, tris-, tetrakis-, and hexakis(aminoacridines). A linear and circular dichroism, electric orientation relaxation, viscometry, and equilibrium study
- 1988
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In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 110:3, s. 932-939
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Journal article (peer-reviewed)abstract
- The interaction between DNA and a series of mono-, bis-, tris-, tetrakis-, and hexakis-intercalating 9-aminoacridines has been studied with flow linear dichroism (LD), circular dichroism (CD), electric orientation relaxation (EOR) techniques, and with viscometry and equilibrium analyses. The orientation of the 9-aminoacridine ligand relative to the average orientation of the DNA bases, measured by LD, shows that with both 9-aminoacridine and the bis(acridines) the in-plane short axes of the acridine ligands are oriented perfectly parallel to the planes of the DNA bases, as expected for classical intercalation, whereas the long axes are found to be significantly tilted. This is supported by the DNA lengthening measured by EOR, which for 9-aminoacridine is 1.5 base-pair units, compared with 1.0 for ethidium bromide. Also in case of the tris(acridines) LD, CD, viscometry, and equilibrium data indicate that all acridine ligands are intercalated. The binding analysis shows an increasing degree of cooperativity in the sequence 9-aminoacridine < bis(acridines) < tris(acridines), and the corresponding binding densities, 4, 8, and 11–14, respectively, are in good agreement with those expected from the nearest-neighbor exclusion principle. The LD and CD measurements show that the tetrakis- and hexakis(acridines), despite long and flexible links, bind to DNA with only three of the acridine ligands intercalated.
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| 4. |
- Grubb, Anders, et al.
(author)
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Production of an amino acid sequence-specific antiserum against human amyloid A (AA) and serum amyloid A (SAA) protein
- 1987
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In: Scandinavian Journal of Clinical and Laboratory Investigation. - 0036-5513. ; 47:6, s. 619-626
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Journal article (peer-reviewed)abstract
- The hydrophilic nonapeptide Ser-Asp-Ala-Arg-Glu-Asn-Ile-Gln-Arg, identical with residues 59-67 of human amyloid protein A (AA) and serum amyloid protein A (SAA), was covalently bound via its carboxyl-terminal end to the carrier-protein keyhole limpet haemocyanin. The complex was injected subcutaneously into ten rabbits. All rabbits produced antisera which, unabsorbed, were specific for AA and SAA. The antisera and their isolated peptide specific antibodies were performance-tested and found to be excellent for demonstration of AA and SAA in immunoblotting and immunohistochemical techniques but unsuitable for immunoprecipitation. Since it is difficult to produce AA- and SAA-specific antisera by procedures earlier described and commercial supplies of good such reagents are unavailable, the easy production of sequence-specific such antisera will facilitate more extended studies of the corresponding antigens for diagnostic and scientific purposes.
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| 5. |
- Löfberg, Helge, et al.
(author)
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Demonstration and classification of amyloidosis in needle biopsies of the kidneys, with special reference to amyloidosis of the AA-type
- 1987
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In: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - : Wiley. - 0108-0164. ; 95A:1-6, s. 357-363
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Journal article (peer-reviewed)abstract
- To examine whether sequence-specific antibodies directed against serum amyloid A were useful in the demonstration and classification of amyloidosis, needle biopsy specimens from the kidneys of 152 cases with renal disorders were investigated using the avidin-biotin-peroxidase complex technique of immunohistochemistry. A distinct immunoreactivity of protein AA was seen in biopsies from all 42 individuals who were clinically classified as having the AA-type of amyloidosis. The stained areas coincided with deposits stained by Congo red. Four of these cases demonstrated immunoreactivity of both protein AA and light immunoglobulin chains and all biopsies except one showed immunoreactivity for the amyloid P-component. After treatment with potassium permanganate, the amyloid deposits in the biopsies of all 42 cases lost their affinity for Congo red. Ten patients with clinical and laboratory findings compatible with the AL-type of amyloidosis were also investigated. All their biopsies demonstrated Congophilic amyloid deposits but none of them showed any immunoreactivity of protein AA. Amyloid deposits of lambda light immunoglobulin chains-but not kappa-were demonstrated in biopsies from four patients. The amyloid P-component was found in biopsies from six individuals and positive Congo red staining after treatment with potassium permanganate was seen in biopsies from four of the cases. Biopsies of 100 patients suffering from non-amyloid renal disorders were also examined. None of them displayed any immunoreactive deposits of protein AA. The investigation shows that amyloid deposits of the AA-type can be identified in needle biopsies when sequence-specific antibodies against serum amyloid A are used in the avidin-biotin-peroxidase complex technique. Both the diagnostic sensitivity (42 of 42) and specificity (110 of 110) of the assay were optimal (1.0). The method was found to be superior to other investigated techniques and useful for classifying amyloidosis in formalin-fixed renal biopsies.
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| 6. |
- Peetre, Christina, et al.
(author)
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A tumor necrosis factor binding protein is present in human biological fluids
- 1988
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In: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 41:5, s. 414-419
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Journal article (peer-reviewed)abstract
- Tumor necrosis factor (TNF) possesses both beneficial and toxic bioactivities. Mechanisms may operate to counteract harmful effects. We have identified a TNF binding protein (TNF-BP), which shows increased levels in serum and urine of patients on regular hemodialysis treatment (RDT). TNF-BP inhibited the specific binding of human recombinant TNF (rTNF) to its cell surface receptor. Results from gel chromatography demonstrated the presence in serum and urine of a macromolecule with an apparent molecular weight of 50,000, which formed a complex with rTNF. A 62-fold purification of TNF-BP from urine of patients on RDT was achieved by ion exchange chromatography and gel chromatography. Partially purified TNF-BP reduced the growth inhibitory effect of rTNF on a susceptible leukemia cell line. TNF-BP may act as a regulator of the biological activity of TNF and could have beneficial effects in certain inflammatory conditions.
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| 7. |
- Löfberg, Helge, et al.
(author)
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The prevalence of renal amyloidosis of the AA-type in a series of 1,158 consecutive autopsies
- 1987
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In: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - : Wiley. - 0108-0164. ; 95A:1-6, s. 297-302
-
Journal article (peer-reviewed)abstract
- To determine the prevalence of renal amyloidosis of the AA-type in a defined population, formalin-fixed specimens from the kidneys of all the cases autopsied in 1983 at The General Hospital of Malmö, Sweden, were investigated using immunohistochemical techniques. Amyloid deposits of protein AA were found in 10 of 1,158 investigated cases and the calculated prevalence was 0.86 per cent. The mean age at death of the individuals with the AA-type of amyloidosis was 79 years. Six of the cases with amyloidosis had rheumatoid arthritis. The avidin-biotin-peroxidase complex technique was found to be superior to the immunofluorescence method and a high sensitivity and specificity was achieved when sequence-specific antibodies against a synthetized nonapeptide corresponding to a hydrophilic segment of the polypeptide chain of protein AA were used in the assay. Nine cases with other types of amyloid deposits in the kidneys were also detected. None of these cases showed any AA immunoreactivity but all of them demonstrated Congophilic deposits which were immunohistochemically stained by antibodies against the amyloid P-component. The prevalence of renal amyloidosis comprising all types of amyloid protein deposits was 1.64 per cent.
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| 8. |
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| 9. |
- Brodelius, Peter, et al.
(author)
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A Phosphorus-31 Nuclear Magnetic Resonance Study of Phosphate Uptake and Storage in Cultured Catharanthus roseus and Daucus carota Plant Cells
- 1985
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In: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 260, s. 3556-3560
-
Journal article (peer-reviewed)abstract
- High resolution "P NMR spectra (103.2 MHz) ofoxygenated Catharanthus roseu8 and Daucus carotacells grown in suspension cultures were obtained usinga solenoidal perfusion probe. The spectra showed resonancesfor various phosphorylated metabolites suchas ATP, ADP, NAD(P)(H), nucleoside diphosphoglucose,and sugar phosphates. The relative levels ofthe phosphorylated metabolites remained constantthroughout the growth curve. No resonances for storagecompounds such as polyphosphates, pyrophosphate,or phytates were observed. Two resolved resonancesfor Pi indicated an intracellular pH of 7.3 and5.7 (or below) for the cytoplasm and vacuoles, respectively.The time course of Pi uptake and storage duringgrowth in fresh culture medium was followed by studyingthe level of vacuolar Pi with 31PN MR (145.7 MHz).Simultaneously, the level of Pi in the culture mediumwas followed with radioactive s2P. C. roseus quicklytakes up all the Pi from the culture medium (maximumrate 1.7 pmol min" g" (dry weight of cells)). The Pi isfirst stored in the vacuoles; subsequently, one part ofthis pool is used to keep a constant cytoplasmic Pi levelwhile another part is apparently accumulated as anNMR invisible Pi store, probably in another cell organelle.In contrast, D. carota does not accumulate Pi inthe vacuoles and consequently it takes up Pi from themedium at a much slower rate (0.05 pmol min" g"(dry weight of cells)).
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| 10. |
- Brodelius, Peter, et al.
(author)
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A Procedure for the Determination of Optimal Chitosan Concentrations for Elicitation of Cultured Plant Cells.
- 1989
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In: Phytochemistry. - 0031-9422 .- 1873-3700. ; 28:10, s. 2651-2654
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Journal article (peer-reviewed)abstract
- An experimental method for determination of the optimum chitosan concentration for elicitation of plant cell suspension cultures is presented. The procedure, which is based on measurements of the conductivity of the culture medium after addition of chitosan, has been applied to suspension cultures of Nicotiana tabacum and Eschscholtzia californica. Increased conductivity of the medium (due to permeabilization of the cells) results in decreased secondary product formation and cell growth. Maximum product formation is observed for cells elicited with the highest chitosan concentration which does not affect membrane permeability.
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