PubMed Health⌕ Search

Biomedical subjects

A Husebekk

Publications and source records attributed to A Husebekk.

34 records · Page 2Linked to original sources
PubMed1992

The complete amino acid sequence of bovine serum amyloid protein A (SAA) and of subspecies of the tissue-deposited amyloid fibril protein A.

Bovine serum amyloid A (SAA) was isolated from the acute phase high density lipoprotein (HDL) fraction of a cow suffering from acute mastitis. The elucidated primary structure revealed a protein consisting of 112 amino acid residues. Compared with SAA proteins from other species, the bovine protein was shown to have an insertion of nine amino acid residues between positions 69 and 70. No microheterogeneity could be observed in the protein. Amyloid fibrils extracted from the kidneys were found to contain at least three subspecies of protein AA, consisting of 68, 81 and about 110 amino acid residues. The amino acid sequences established for the protein AA subspecies revealed no microheterogeneity, and were identical to that elucidated for protein SAA.

Amino Acid Sequence↗
PubMed1991

[Measurement of C-reactive protein gives valuable information in patients with all types of inflammation].

C-reactive protein (CRP) is a characteristic inflammation marker. In healthy individuals the serum concentration of CRP is less than 10 mg/l. With serious inflammation the serum concentration may increase to more than 1,000 fold. With few exceptions the serum level of CRP increases in all types of inflammations, both infectious and non-infectious. Bacterial infections seem to give the best stimulation to CRP synthesis. Knowledge about the metabolism of CRP after stimulation, the conditions giving increase in the serum concentration of CRP and the conditions which do not, is a prerequisite for evaluation of CRP levels in individual patients. This review discusses knowledge about CRP in general, and the serum level of CRP in different clinical situations.

Adult↗
PubMed1989

The primary structure of equine serum amyloid A (SAA) protein.

The complete amino acid sequence of equine serum amyloid A (SAA) was elucidated. The protein consists of 110 amino acid residues and contains an 8-amino acid residue insertion tentatively located between positions 69 and 70, as compared with human SAA. Microheterogeneities were detected at positions 16, 44, and 59, compatible with the existence of more than one SAA gene in the horse. This corresponds to the situation in man and mouse. Pronounced homology with SAA from man and several animal species was observed, thus confirming the conserved structure of this acute phase reactant and apoprotein of high-density lipoprotein (HDL).

Amino Acid Sequence↗
PubMed1988

High-density lipoprotein has different binding capacity for different apoproteins. The amyloidogenic apoproteins are easier to displace from high-density lipoprotein.

Purified human amyloid protein A (AA) or serum amyloid protein A (SAA) was incubated with normal human high-density lipoprotein (HDL). After ultracentrifugation the amount of AA or SAA associated with HDL was measured. It was found that the binding capacity of HDL for SAA was higher than that for AA. Incubation of these in vitro associated HDL-AA and HDL-SAA complexes with purified apo AI or apo AII resulted in varying degrees of displacement of the associated AA or SAA from HDL. Under the experimental conditions used, apo AI was able to displace AA from HDL, while apo AII was able to displace both SAA and AA. This indicates that the binding capacity of HDL is different for SAA and AA. Mouse acute-phase HDL was isolated and the native complexes were incubated with human apo AII. SAA2, the amyloidogenic SAA variant in mice, was displaced from HDL to a greater extent than SAA1, indicating a lower binding capacity for the amyloidogenic SAA variant for the HDL complexes.

Animals↗
PubMed1988

Characterization of bovine amyloid proteins SAA and AA.

The bovine serum amyloid A (SAA) and tissue amyloid A (AA) proteins were isolated and characterized. SAA was isolated from acute phase high density lipoprotein (HDL) of a cow suffering from acute mastitis, and was identified by amino acid sequence analysis. No AA-like protein was found in complex with HDL in serum. Amyloid fibrils isolated from a bovine kidney contained a 9 kDa AA protein and a considerable amount of a 14 kDa protein. Amino acid sequence analysis showed that the largest protein probably represents undegraded SAA. This is an interesting observation which confirms previous works indicating that SAA can be incorporated in the amyloid fibrils without a prior degradation to AA. The partial amino acid sequences of bovine SAA and AA were strikingly homologous to the sequences of corresponding proteins in man and other species.

Amino Acid Sequence↗
PubMed1988

BK virus infection in patients with AIDS.

Antibodies to the human papovavirus BK (BKV) were determined in a group of 25 homo- and bisexual males with AIDS, 24 men with AIDS-related complex (ARC) and 18 healthy male homosexual controls from Copenhagen. The AIDS patients had a significantly lower prevalence and level of anti-BKV antibodies tested by IgG-ELISA, hemagglutination inhibition and neutralization tests than the ARC patients. About half of the anti-BKV antibody positive AIDS patients demonstrated primary infections or reactivations but without specific IgM production. The titers were low compared to primary infections in children. At least 2 of the patients lost their serological markers in the late phase of the disease. It is therefore possible that the low prevalence of BKV infection in AIDS patients is caused by loss of serological markers even if the level of total IgG is normal or increased.

AIDS-Related Complex↗
PubMed1987

Characterization of amyloid proteins AA and SAA as apolipoproteins of high density lipoprotein (HDL). Displacement of SAA from the HDL-SAA complex by apo AI and apo AII.

An AA-like protein with a molecular weight of 8600 complexed to high-density lipoprotein (HDL) was demonstrated in several acute-phase sera with high levels of SAA. The protein 'apo AA' (to distinguish it from tissue AA) was isolated by elution from sodium dodecyl sulphate (SDS)-polyacrylamide gel, and showed antigenic identity with purified tissue protein AA in double immunodiffusion. Normal HDL was shown to bind purified tissue AA in vitro. When the in vitro-associated HDL-AA complexes were given intravenously to mice during induction of amyloidosis, human AA was incorporated in the amyloid fibrils. Both apo AI and apo AII were shown to displace SAA from acute phase HDL when added to HDL-SAA complexes in vitro. This might be of importance in amyloidogenesis, as the liver and the small intestine, which are the main sites for AI and AII synthesis, are also sites of early amyloid deposition.

Acute-Phase Reaction↗
PubMed1987

The amino acid sequence of an amyloid fibril protein AA isolated from the horse.

The amino acid sequence of the amyloid fibril protein AA from horse was established from characterization of cyanogen bromide fragments, tryptic peptides, and a peptide derived from a digest with Staphylococcus aureus V8 proteinase. The protein was found to consist of 80 amino acid residues. Sequence homologies with protein AA from other species were very striking, and revealed an insertion of two amino acid residues between positions 72 and 73. In position 44, two amino acid residues were found which provide further evidence for a polymorphism in the amyloid fibril protein AA.

Amino Acid Sequence↗
PubMed1986

Serum amyloid A protein in acute myocardial infarction.

Tissue injury including myocardial infarction leads to a variety of changes in plasma proteins commonly referred to as "the acute phase response". In this report the concentrations of serum amyloid A protein (SAA) were measured serially in 6 patients with myocardial infarction and 4 with angina. SAA was found to be increased in all patients with infarction, but in no patients with angina. Significantly increased SAA levels were detected 12 hours after the peak level of creatine kinase, and the concentrations of SAA seemed to correlate to the amount of damaged tissue. The SAA-response was both faster and more extensive than the response of C-reactive protein (CRP), but the correlation between SAA and CRP was very good.

Aspartate Aminotransferases↗
PubMed1986

Characterization of amyloid protein AA and its serum precursor SAA in the horse.

Amyloid was extracted from the liver of a horse that had developed amyloidosis after being used for several years for the production of antibodies to bacterial antigens. The amyloid fibrils were shown to be of the AA type. Two AA proteins with molecular weights of 9000 and 11,000 and with identical partial N-terminal amino acid sequences were identified. Marked structural homology with AA from other species including man was seen, although clear species-related antigenic specificity was observed. SAA isolated from an acute phase (septic abortion) horse serum was identical to AA with respect to antigenicity and the 10 first N-terminal amino acid residues that have been studied up to now. The bulk of SAA was present in the high-density lipoprotein complex in serum. Also SAA was heterogeneous with respect to size, most molecules having a molecular weight of 11,000, and a minority 9000.

Amino Acid Sequence↗
PubMed1986

Serum amyloid protein A (SAA): an indicator of inflammation in AIDS and AIDS-related complex (ARC).

The acute phase protein serum amyloid A (SAA) and C-reactive protein (CRP) were measured in a group of 30 homo- and bisexual males with AIDS, 31 males with AIDS-related complex (ARC) and 23 healthy male homosexual controls (HC) in Copenhagen. The mean values of SAA and CRP were significantly higher in the AIDS group compared to the two other groups. SAA was elevated also in the ARC group, whereas the mean CRP value was normal. No increase in SAA and CRP was found in the HC group. The AIDS patients with Pneumocystis carinii infections had the highest SAA values, those with Kaposi's sarcoma the lowest. The elevations in SAA and CRP preceded episodes of acute opportunistic infections often by several days before the infectious agents were identified. We conclude that patients with AIDS are able to establish an acute phase response as reflected by elevated SAA and CRP, and that measurement of these proteins may be of diagnostic and prognostic value.

AIDS-Related Complex↗
PubMed1985

Transformation of amyloid precursor SAA to protein AA and incorporation in amyloid fibrils in vivo.

Experimental amyloidosis was induced in mice by intraperitoneal injections of endotoxin (lipopolysaccharide (LPS)). In addition to LPS, a group of mice received high-density lipoprotein (HDL)-SAA complexes isolated from human acute-phase serum, whereas a group of control mice received saline in addition to LPS. Isolated amyloid fibrils from the mice given HDL-SAA contained human AA protein, as shown by immunodiffusion, immunoblot, and enzyme-linked immunosorbent assay techniques, in addition to mouse AA. In contrast, amyloid from the control mice contained exclusively AA of mouse origin. Thus, the experiments provided solid evidence that SAA is the precursor for amyloid fibril protein AA.

Amyloid↗
PubMedDate not supplied

Minimal expression of blood group A antigen on thrombocytes from A2 individuals.

Two multiply transfused group O patients developed refractoriness to random-donor platelet transfusions. Both had high-titer IgG antibodies to group A and B antigens. Subsequent transfusions with ABO-compatible platelets were successful, suggesting that the ABO blood group system is significant in the development of refractoriness to platelet transfusions. By indirect immunofluorescence, the patients' IgG anti-A reacted with platelets from group A1 donors but not with those from group A2 donors. A2 platelets were at least 38 times less efficient at adsorbing a mouse monoclonal anti-A; the difference between the adsorbence capacities of A2 and O platelets was minimal. Transfusion of A2 platelets, unlike that of A1 platelets, effected a good increment in the platelet counts of these two patients. The results indicate that the expression of A2 antigen on platelets from A2 subjects is minimal.

ABO Blood-Group System↗