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3.
Ekström, Per A R, et al.
(författare)
Impaired nerve regeneration in streptozotocin-diabetic rats. Effects of treatment with an aldose reductase inhibitor
1989
Ingår i: Journal of the Neurological Sciences. - 0022-510X. ; 93:2-3, s. 231-237
Forskningsöversikt (refereegranskat) abstract
Rats with streptozotocin-induced diabetes have a decreased rate of sciatic nerve regeneration. We studied the effects on this defect of treatment with the aldose reductase inhibitor, ponalrestat (25 mg/kg per day via an endogastric tube). The nerves of diabetic rats were crush-injured at 5 weeks of diabetes and regeneration evaluated 7 days later with the pinch-reflex test. Ponalrestat treatment was started at day 3 after streptozotocin injection and was continued for the whole experimental period, i.e. until 6 weeks of diabetes. The treatment prevented effectively the accumulation of sorbitol and fructose in the nerves of diabetic rats, but was without effect on the sciatic nerve regeneration (controls 21.8 ± 1.2 mm/7 days (mean ± SEM, n = 6), untreated diabetics 15.8 ± 1.8 (n = 7), ponalrestat-treated diabetics 16.2 ± 1.0 (n = 10)). The results indicate that there is no connection between increased sorbitol pathway flux and impaired regeneration in streptozotocin diabetic rats.
4.
Olafsson, Isleifur, et al.
(författare)
Production, characterization and use of monoclonal antibodies against the major extracellular human cysteine proteinase inhibitors cystatin C and kininogen
1988
Ingår i: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 48:6, s. 573-582
Tidskriftsartikel (refereegranskat) abstract
Murine monoclonal antibodies against the major cysteine proteinase inhibitors of human biological fluids, cystatin C and kininogen, were produced. The cystatin C antibody, HCC3, with a Ka of 2times107 l/mol, increased the inhibition of papain by cystatin C and was suitable for use in immunoblotting, immunohistochemistry and in the construction of a sensitive sandwich enzyme immunoassay for quantification of cystatin C. It recognized not only free cystatin C but also cystatin C in complexes with cysteine proteinases. The kininogen antibody, HK4, was directed against the third, cysteine proteinase inhibitory domain of the heavy chain of kininogen (Ka=1times107 l/mol), but did not influence the papain inhibitory activity of kininogen. It reacted with free kininogen as well as kininogen in complex with cysteine proteinases. Both antibodies could be used for the production of specific immunosorbents.
5.
Escribano, Julio, et al.
(författare)
Identification of retinol as one of the protein HC chromophores
1988
Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 0006-291X. ; 155:3, s. 1424-1429
Tidskriftsartikel (refereegranskat) abstract
Protein HC (alias alpha 1-microglobulin) contains so far unidentified yellow-brown fluorescent chromophores. Several preparations of human protein HC were extracted with hexane. Most of the extracts contained a substance which, upon reversed-phase HPLC, co-eluted with all-trans- retinol and had an absorption spectrum identical to that of retinol. The substance was also, like retinol, destroyed by exposure to ultraviolet light and acid pH. These observations strongly support the proposal that protein HC is a member of the newly defined lipocalin protein superfamily. The highest retinol-protein HC molar ratio of the investigated protein HC preparations was 1.6 x 10(-3) indicating that retinol is not the only ligand bound to protein HC. This was confirmed by comparing the absorption spectrum of protein HC before and after hexane extraction.
6.
Hansson, H A, et al.
(författare)
Evidence indicating trophic importance of IGF-I in regenerating peripheral nerves
1986
Ingår i: Acta Physiologica Scandinavica. - : Wiley. - 0001-6772 .- 1365-201X. ; 126:4, s. 14-609
Tidskriftsartikel (refereegranskat) abstract
The mechanisms influencing regeneration of peripheral nerves are incompletely known, but growth factors are supposed to play a key role. In the present study, we demonstrate, with the aid of immunohistochemical methods, that somatomedin C (Sm-C/insulin-like growth factor I/IGF-I) rapidly increased from low to high concentrations, reaching peak values in 2 weeks, in regenerating sciatic nerves of adult rats. In addition, IGF-I was demonstrated extracellularly, never observed in the control nerves. Reactive Schwann cells appeared to be the major source for IGF-synthesis. Higher concentrations were seen in tubulated nerves as compared to sutured ones. It is proposed that IGF-I exerts important growth supporting effects on regenerating peripheral nerves.
7.
Malmström, P., et al.
(författare)
Countercurrent Distribution of Lymphocytes from Human Peripheral Blood in an Aqueous Two-Phase System : I. Separation into Subsets of Lymphocytes Bearing Distinctive Markers’
1980
Ingår i: Cellular Immunology. - : Elsevier BV. - 0008-8749. ; 53, s. 39-50
Tidskriftsartikel (refereegranskat) abstract
Lymphocytes from human peripheral blood have been separated by countercurrent distribution in a charged aqueous two-phase system composed of Dextran T 500 and polyethylene glycol 6000 with a cell yield of 59–88% and viability above 90%. A highly reproducible partition pattern was seen with four distinct peaks. Lymphocytes with surface membrane immunoglobulin (SmIg) were located in the first part of the distribution corresponding mainly to peak I. T lymphocytes as detected by E rosetting and α-naphthyl acetate esterase (ANAE) staining showed a broad distribution with a maximum in peaks II and III. ANAE-negative lymphocytes were seen in both extremes of the distribution, corresponding to B cells in the first part and to a population of E− and SmIg− lymphocytes in the last part. Monocytes were present in all fractions with some enrichment in peaks II–IV. Lymphocytes with low-affinity Fc receptors were found in B-cell-containing fractions in the first part of the distribution, but also in the last part. Lymphocytes with high-affinity Fc receptors were detected mainly in peak IV. It is thus demonstrated that peripheral blood lymphocytes can be fractionated into subpopulations enriched in cells with characteristic markers.markers.
8.
Peetre, Christina, et al.
(författare)
A tumor necrosis factor binding protein is present in human biological fluids
1988
Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 41:5, s. 414-419
Tidskriftsartikel (refereegranskat) 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.
9.
Agardh, Carl-David, et al.
(författare)
The influence of plasma insulin concentrations on tissue insulin levels in rodents: a study of the diabetic Chinese hamster and the ob/ob mouse
1986
Ingår i: Metabolism, Clinical and Experimental. - : Elsevier BV. - 1532-8600. ; 35:3, s. 244-249
Tidskriftsartikel (refereegranskat) abstract
Immunoreactive insulin was measured in acid-ethanol extracts of kidney, brain, liver, and heart from genetically diabetic Chinese hamsters and their nondiabetic controls and from obese (ob/ob) mice and their thin littermates. Selected samples were filtered on Sephadex G-50 columns and the insulin concentration determined. There was a good correlation between the insulin level measured in the acid-ethanol extracts of tissues and the insulin level after gel filtration, suggesting that the concentration measured in the whole extract is representative of the true insulin content. The present data demonstrate that different extrapancreatic organs contain characteristic amounts of insulin that are often (sometimes several-fold) higher than the insulin level of plasma. The tissue insulin concentrations also exhibit a wide range of values, with occasional high values. The data also show a direct correlation between plasma and kidney insulins but no relationship between plasma and brain insulins and a mixed correlation among plasma and liver and heart insulins.
10.
Akerstrom, B., et al.
(författare)
Structural relationship between α1-microglobulin from man, guinea-pig, rat and rabbit
1988
Ingår i: European Journal of Biochemistry. - 0014-2956. ; 170:1-2, s. 143-148
Tidskriftsartikel (refereegranskat) abstract
Rabbit α1-microglobulin was purified from the urine of sodium-chromate-treated animals by the use of gel chromatography on Sephadex G-100 affinity chromatography on concanavalin-A - Sepharose and ion-exchange chromatography on DEAE-Sephadex. Rabbit α1-microglobulin had a molecular mass of 25.6 kDa on SDS/polyacrylamide gel electrophoresis. α1-microglobulin has previously been purified from the urine of humans, guinea-pigs and rats by similar methods, and the molecular masses of the four homologues were compared by SDS/polyacrylamide gel electrophoresis and gel chromatography in a denaturing medium. By these two methods the human homologue was 6 kDa and 3 kDa larger, respectively, than the other three proteins. Endoglycosidase F digestion of α1-microglobulin, followed by SDS/polyacrylamide gel electrophoresis, revealed three protein bands in the human α1-microglobulin sample, and only two bands in guinea-pig, rat and rabbit α1-microglobulin, with a gap between each band of 2.6-2.9 kDa. The amino-terminal amino acid sequences of the four homologues were determined and between 72% and 81% homology was seen. The five amino-terminal amino acids present in the other species were missing in guinea-pig α1-microglobulin. Our results indicate that human α1-microglobulin is substituted with two N-linked oligosaccharides, while only one is attached to each of the other α1-microglobulins, and that the extra glycosylamine-linked oligosaccharide in the human protein is attached to asparagine in position 17. Finally it is shown that all four homologues inhibit antigen stimulation of human lymphocytes, a finding which is consistent with our previous suggestion that the N-linked oligosaccharides carry the immunosuppressive activity of α1-microglobulin.
