Search PubMed⌕ Search

Biomedical subjects

E Gruys

Publications and source records attributed to E Gruys.

At least 19 recordsLinked to original sources
PubMed1999

Familial amyloidosis in cats: Siamese and Abyssinian AA proteins differ in primary sequence and pattern of deposition.

Familial AA amyloidosis is a hereditary trait in Abyssinian cats, with the kidney as the main target organ. The amino acid sequence of the amyloid A protein of the Abyssinian cat has been described earlier. Recently, familial amyloidosis has been found in Siamese cats, with the liver as the main target organ. In the present paper, we describe the complete amino amid sequence of the major constituent protein, of two Siamese cats. Siamese hepatic protein AA showed homology with, but was different from all feline SAA and AA sequences hitherto reported. Two substitutions (46Q-R and 52A-V) from the Abyssinian protein sequence were identified, one of which (46Q-R) is a non-homologous substitution not found in mammalian SAA, but is present in two bird AA amyloid proteins. This shows the presence of an unique amyloidogenic SAA isotype in Siamese cats. Both the Siamese and the Abyssinian sequence are amyloidogenic, thus making identification of amyloidogenic residues difficult. Apart from the apparent inherent amyloidogenicity of SAA, it can not be excluded that certain amino acid substitutions could enhance its amyloidogenicity but also could contribute to tissue predilection in amyloidosis.

Amino Acid Sequence↗
PubMed1999

Casein related amyloid, characterization of a new and unique amyloid protein isolated from bovine corpora amylacea.

Amyloid bodies can be found in mammary secretory tissue of various species. These corpora amylacea (CA) have a lamellated structure, contain amyloid fibrils and are predominantly located in the alveolar lumina. The nature of the amyloid was not known, but CA were suggested to originate either from milk casein or mammary alveolar epithelial keratin. In the present report, bovine CA were analyzed histochemically. Furthermore, CA were isolated, analyzed and the amyloid was purified and characterized by amino acid sequencing. CA amyloid appeared to be potassium permanganate sensitive and tryptophan positive, and in this respect different from most other amyloid types except for AA and beta-2 microglobulin amyloid. Gel filtration of purified amyloid fibrils showed a HMW peak and a major 4 kD peak. N-terminal amino acid sequencing showed the amyloid to consist of tryptic-like peptides with an unusually high content of amino acids with bulky side chains. The amyloid protein was identified as derived from alpha-S2-casein. The fragments are of varying length (32, 33 and 45 amino acids), but all start at position 81 of alpha-S2-casein. We have identified a new and unique amyloid protein, and we propose to designate it as A alpha-S2C according to the guidelines for amyloid nomenclature.

Amino Acid Sequence↗
PubMed1998

Release of proinflammatory cytokines related to luteolysis and the periparturient acute phase response in prostaglandin-induced parturition in cows.

An acute phase response was previously found in cows at parturition, which might be associated with uterine cytokine release. Five late pregnant cows were implanted with vascular catheters in both the maternal aorta and uterine vein. Blood samples were taken to study temporal relationships between changing plasma levels of proinflammatory cytokines and the periparturient acute phase response following prostaglandin (PG)-induced luteolysis at Day 275 of gestation. The plasma levels of three proinflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) and interleukin-6 (IL-6), as well as progesterone (P4), PGFM and serum amyloid A (SAA) were measured every 4 h between PG induction and expulsion of the calf. In the arterial plasma, progesterone levels dropped to baseline levels within 10 h following PG treatment, indicative of complete luteolysis. Contrary to expectations, the uterine vein samples showed lower proinflammatory cytokine levels compared with the maternal aorta values. A classical acute phase response, as assessed by SAA, was observed during the expulsive stage, but not during luteolysis.

Animals↗
PubMed1998

The role of various agents in chicken amyloid arthropathy.

The results of an inventory of field cases of amyloid arthropathy in chickens and of routine post-mortem recordings over a two years period are described. Studies were also performed to evaluate the amyloidogenic potential of arthrotropic bacterial species (Staphylococcus aureus, Escherichia coli and Salmonella enteritidis) isolated from chickens as well as several Enterococcus faecalis isolates compared to the amyloidogenic E. faecalis isolate (previously isolated from amyloidotic joints). As chicken anemia virus was also isolated from amyloidotic joints of field cases, it was also screened for its amyloidogenic potential. In another experiment, Mycoplasma synoviae, inactivated E. faecalis isolate 6085.94, Freund's adjuvant and an arthrotropic reovirus field isolate were also screened for amyloidogenicity by intra-articular injection. These studies showed that the ability to elicit extensive amyloid arthropathy is reserved primarily to E. faecalis, but that this property is not common to every E. faecalis isolate. Intra-articular application of complete Freund's adjuvant led to the formation of extensive joint amyloid deposits. Of the other micro-organisms studied, S. aureus, S. enteritidis and E. coli were also able to cause joint amyloidosis, but in very small amounts. Inactivated E. faecalis, chicken anemia virus and reovirus did not cause amyloid arthropathy after intra-articular inoculation. This study is consistent with results of the analyses of previous field cases and of the induction of amyloid arthropathy in chickens, suggesting a considerable role for E. faecalis in this clinical-pathological entity. Finally, strain typing by analysis of chromosomal DNA restriction endonuclease digests by pulsed-field gel electrophoresis (PFGE) of amyloidogenic, non-amyloidogenic, amyloid-associated and other E. faecalis isolates from various origins showed that all amyloidogenic and amyloid-associated E. faecalis isolates had similar restriction digests, suggesting clonal spread.

Amyloidosis↗
PubMed1998

Polyarthritis and periostitis induced by Escherichia coli. Lipopolysaccharide injection in young male hamsters.

OBJECTIVE: To describe the clinicopathological manifestations of lipopolysaccharide (LPS) induced arthritis in the hamster and to compare its time of onset, duration, and severity with other forms of experimentally induced arthritis. METHODS: A preparation containing 30 microg LPS from Escherichia coli was injected subcutaneously for 5 to 21 days into young male hamsters (Mesocricetus auratus). Arthritis was quantified by measuring soft tissue swelling of affected joints with calipers. After decalcification, paraffin sections were cut and stained with hematoxylin and eosin, Giemsa, and azan. Acute phase reactant apolipoprotein serum amyloid A (apoSAA) levels were determined by ELISA. RESULTS: Symmetrical polyarthritis developed within 3 days and persisted for 14-21 days, provided the hamsters received daily LPS injections. Most prominent were lesions in the carpal-metacarpal joints of the front legs and in the tarsal-metatarsal joints of the hind legs. Animals in whom LPS injections were discontinued after 4 or 7 days recovered completely. Histological findings of exudative synovitis, periarticular soft tissue swelling, and juxtaarticular periostitis were associated with a sharp rise in serum titers of apoSAA. CONCLUSION: The unusually rapid onset of arthritis and periostitis in this experimental animal model suggests that its systemic manifestations were not mediated by a classical immune response, and may represent an "innate" response of targeted cells within the synovial membrane and periosteum to bacterial cell wall endotoxins.

Animals↗
PubMed1997

Generalized AA-amyloidosis in Siamese and Oriental cats.

During a 7 year period (1987-1994), 194 Siamese cats including a colour variant designated Oriental cat, were presented for post-mortem examination. Twelve of these animals (6.2%) were diagnosed with amyloidosis. Major gross pathological findings included enlarged pale livers with haemorrhages, pale and swollen spleens, and dilated intestines. Deposits of amyloid were found in these tissues. The amyloid was found to cross-react with anti dog AA-antiserum when examined with peroxidase antiperoxidase (PAP) staining (four cases). Amyloid fibrils were purified by the water extraction method and its major constituting protein (AA) was isolated by gel filtration. Amino acid sequence analysis of this protein from a Siamese cat and an Abyssinian cat revealed a significant difference between these breeds. In the Siamese protein AA two amino acid substitutions (46 R for Q and 52 V for A) were encountered. This finding indicates the existence of a new feline amyloid A protein occurring in the Siamese breed which differs from presently known (apoS)AA-proteins. Additionally, the pedigree analysis of affected cats suggests a familial trait.

Amino Acid Sequence↗
PubMed1997

Light microscopic, immunohistochemical, and electron microscopic features of amyloid arthropathy in chickens.

Amyloid arthropathy has been recently recognized as a spontaneous syndrome in chickens. Predominantly, femorotibial and tarsometatarsal joints were affected, showing (peri) articular orange amyloid deposits. Immunohistochemical evaluation revealed the amyloid to be of the reactive type. Induction of amyloid arthropathy in chickens was carried out using a single intravenous injection of Enterococcus faecalis cultures. In the naturally occurring and the induced cases, amyloid deposits were found in the hypertrophic synovial villi and in the articular cartilage, particularly in the superficial layer and in the nutritional blood vessel walls. Highly sulfated glycosaminoglycans (GAGs) were found in the amyloid deposits. Ultrastructurally, bundles of amyloid fibrils were seen in invaginations of synoviocytes and chondrocytes. Immunogold electron microscopy failed to reveal signs of intracellular amyloid formation. The predilection site for amyloid deposition in the major leg joints of the chickens with reactive amyloid could be explained by the arthritic condition caused by Enterococcus faecalis bacteriaemia. The polyarthritis triggers hepatic acute phase protein synthesis and increases the vascular serum amyloid A (SAA) supply to the joint. Inflammatory and degenerative changes in the articular cartilage and adjoining tissues result in an increase of highly sulphated GAGs, which are considered to enhance deposition of SAA as amyloid.

Amyloid↗
PubMed1997

Pseudorabies virus infections in pigs. Role of viral proteins in virulence, pathogenesis and transmission.

This paper reviews new findings on the biological functions of pseudorabies virus (PRV) proteins. It focuses on the role of PRV proteins in the pathogenicity, immunogenicity and transmission of PRV vaccine strains in pigs. Furthermore, it evaluates potential risks that are connected with the use of PRV vector strains. Special emphasis is placed upon the spread of genetically engineered vaccine strains within pigs or between pigs.

Animals↗
PubMed1996

Primary bovine hepatocytes in the study of cytokine induced acute-phase protein secretion in vitro.

To investigate the utility of primary cultures of bovine hepatocytes for compartmentalized acute phase protein studies the secretion of serum amyloid-A (SAA) and haptoglobin (Hp) was measured after stimulation by pro-inflammatory cytokines (recombinant human IL-6 (rhIL-6) and recombinant human tumour necrosis factor-alpha (rhTNF-alpha)). During the incubation period of the experiment, the SAA and Hp secretion into the culture medium increased (P < 0.05). SAA concentrations showed an additional increase following treatment with each of the cytokines (P < 0.01). Hp concentrations remained unchanged, whereas incubation with a combination of both resulted in a significant increase of the medium concentration of both SAA (P < 0.01) and Hp (P < 0.05). From these findings it is concluded that primary bovine hepatocytes can be used for in vitro studies on acute-phase protein secretion.

Acute-Phase Proteins↗
PubMed1996

Characterisation of the acute phase response of heifers to a prolonged low dose infusion of lipopolysaccharide.

The effect of a prolonged low dose infusion of bacterial lipopolysaccharide (LPS) on acute phase-like reactions was examined in heifers. LPS (2 micrograms kg-1 dissolved in 100 ml water), or saline was infused (at 1 ml min-1) intravenously for 100 minutes and blood samples were taken at various times before, during and after the infusion. The serum concentrations of tumour necrosis factor-alpha (TNF alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and serum amyloid A (SAA) and the rectal temperature increased in response to the LPS infusion. Serum TNF alpha increased before the increases in IL-1 beta and IL-6 and remained high from 20 minutes after the onset of the infusion until the end of the sampling period (six hours). The LPS-induced increases in serum IL-1 beta and IL-6 were biphasic. Plasma cortisol and lactate concentrations also increased, and plasma glucose and beta-hydroxybutyrate concentrations decreased in response to the LPS infusion. The similarity of these reactions to changes observed in response to bacterial infections shows that the prolonged infusion of low doses of LPS is a good model for studying the acute phase response to Gram-negative bacterial infection in heifers.

Acute-Phase Proteins↗
PubMed1996

Chicken joint amyloid protein is of the AA-type. I. Characterization of the amyloid protein.

Amyloid fibrils were extracted from deposits in joint tissue of heavy breed layers with spontaneous amyloid arthropathy and characterized as being of the AA-type. Amino acid sequencing revealed a pattern quite similar to duck AA. Acute phase sera of chicken experimentally injected with Enterococcus faecalis showed a SAA-protein like band cross reacting with anti-chicken AA in immunoblot.

Acrylic Resins↗