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Biomedical subjects

S D Carter

Publications and source records attributed to S D Carter.

At least 73 records · Page 4Linked to original sources
PubMed1998

The frequent detection of a treponeme in bovine digital dermatitis by immunocytochemistry and polymerase chain reaction.

A study was carried out to determine whether spirochaetes are frequently associated with digital dermatitis in United Kingdom (UK) dairy cattle. Histopathological examination of lesions using a silver stain showed a large number of unidentified spirochaete-like organisms present in digital dermatitis hoof skin tissue in all examined biopsies. Immunocytochemical staining demonstrated that spirochaetes in skin lesions were identified by polyclonal antisera to Borrelia burgdorferi, Treponema denticola and Treponema vincentii (again all biopsies were positively stained), whereas monoclonal antibodies to B. burgdorferi and any Treponema pallidum did not stain any organisms in all biopsies. A PCR of 16S rRNA, previously shown to be specific for a new treponeme, was employed and produced positive results from 82.4% of digital dermatitis tissues. It is concluded that this spirochaete (or related spirochaetes), which is similar to human oral treponemes, is frequently associated with, and may be responsible for, pathological changes in digital dermatitis.

Animals↗
PubMed1998

Isolation and characterisation of immunoglobulin g and IgG subclasses of the African elephant (Loxodonta africana).

Immunoglobulins were precipitated from pooled African elephant sera with ammonium sulphate and separated by gel filtration and fast protein liquid chromatography (ion exchange). Analysis of the fractions by SDS-PAGE showed IgG of 150 kDa with up to five subclasses, each having heavy chains of 57 kDa and light chains of 27 kDa. Three monoclonal antibodies against human IgG and polyclonal antibodies against canine, bovine, cameline, equine, phocine and feline IgG showed strong cross-reactivity with the African elephant IgG subclasses. No serum molecules corresponding to IgM or IgA could be detected, even when ammonium sulphate precipitation was used at 50% saturation.

Animals↗
PubMed1998

Isolation and identification of canine matrix metalloproteinase-2 (MMP-2).

A canine gelatinase, with an apparent molecular mass of 62 kDa in non-reducing zymography, is produced by fibroblasts, chondrocytes and a myelomonocytic cell line. The enzyme has similar characteristics to human matrix metalloproteinase (MMP) 2 and cross-reacts in Western blotting analysis with a sheep polyclonal antiserum raised against human MMP-2. The 62 kDa canine protein was purified from cell culture media, and the N-terminal amino acid sequence determined following blotting on to a polyvinylidene difluoride (PVDF) membrane. The sequence was 87% identical to that published for human MMP-2. We therefore consider this enzyme to be canine MMP-2.

Amino Acid Sequence↗
PubMed1998

The effect of drugs commonly used in the treatment of equine articular disorders on the activity of equine matrix metalloproteinase-2 and 9.

Loss of articular cartilage, which is the most important pathological lesion occurring in osteoarthritis, has been shown to be enzymatically mediated. The matrix metalloproteinases (MMPs) are a group of enzymes which have been implicated in this degradation of articular cartilage matrix. The use of pharmacological agents to inhibit this catabolic process in the joint is a potential route for therapeutic intervention. The gelatinase MMPs, MMPs-2 and 9, were purified by affinity chromatography from equine cell cultures. The ability of phenylbutazone, flunixin, betamethasone, dexamethasone, methylprednisolone acetate (MPA), hyaluronan, pentosan polysulphate and polysulphated glycosaminoglycan (PSGAG) to inhibit equine MMPs-2 and 9 were assessed by two degradation assays. Whilst some agents did have direct effects on MMP activity, these effects were only obtained at concentrations which were unlikely to be achieved for any length of time in vivo. It is improbable that any pharmacological agent, currently used in the horse, has a significant effect on gelatinase MMP activity.

Animals↗
PubMed1998

Equine TIMP-1 and TIMP-2: identification, activity and cellular sources.

Matrix metalloproteinases (MMPs) are the main enzymes involved in connective tissue turnover. Regulation of MMPs is achieved by controlling production, activation of the pro-enzymes together with the presence of inhibitors, such as, tissue inhibitors of metalloproteinases (TIMPS). The presence of TIMPs in equine synovial fluid was assessed by the ability of the fluid to inhibit equine MMP-9 activity using a gelatin degradation ELISA. The cellular source of the TIMPs was determined using culture supernatants of resident articular cells (chondrocytes and synovial fibroblasts) and invading inflammatory cells (polymorph neutrophils [PMN] and peripheral blood monocytes [PBM]). The TIMPs were characterised further using reverse zymography, affinity chromatography and N-terminal amino acid sequencing. Synovial fluid was recovered from horses with articular sepsis and aseptic joint disease (AJD) and compared with that from normal horses (n = 4). TIMP activity was minimal in articular sepsis but significantly increased, albeit a small increase, in AJD when compared to normal (P<0.05). Cell culture supernatants from synovial fibroblasts, chondrocytes and PBMs contained TIMP activity, although supernatants from PMN cell culture did not. Reverse zymography of synovial fluid recovered from normal and AJD horses showed two protein bands, 22 and 28 kDa in size, exhibiting inhibitory activity against MMP-9. Reverse zymography of culture supernatants of synovial fibroblasts and chondrocytes gave similar results whereas the culture supernatants from PMNs and PBMs showed the presence of only the 28 kDa protein. The N-terminal amino acid sequence was obtained for the 22 kDa protein and revealed a 66% homology with human TIMP-2. The identification of TIMPs in equine synovial fluids and cell culture supernatants suggest that they may have a fundamental role in the homeostasis of the normal joint and in the excess proteolysis which occurs in articular disease in the horse.

Amino Acid Sequence↗
PubMed1998

Influence of porcine somatotropin on the phosphorus requirement of finishing pigs: I. Performance and bone characteristics.

We conducted two experiments to evaluate the effects of recombinant porcine somatotropin (pST) on the P requirement of finishing pigs. Corn-soybean meal diets with varying levels of P were fed, and Ca was adjusted to maintain a Ca:P ratio of 1.1:1. In Exp. 1, 96 pigs were fed dietary P concentrations of .35, .45, and .65% from 75 to 109 kg BW. One-half of the pigs were injected daily with 4 mg of pST. Pigs treated with pST consumed less feed and gained more efficiently than untreated pigs (P < .01). Increasing the dietary P level produced linear (P < .05) improvements in most metacarpal-metatarsal (MM) and femur traits. Administration of pST increased (P < .02) bone weight, but it reduced (P < .03) bone strength and the percentage of ash. The increases in percentage of ash and ash accretion associated with increasing dietary P were more pronounced in pST-treated pigs than in untreated pigs (pST x P, P < .01). Experiment 2 consisted of 66 pigs fed six dietary P concentrations (.35, .50, .65, .80, .95, and 1.10%) from 72 to 114 kg. One-half of the pigs were injected daily with 4 mg of pST. Pigs treated with pST gained faster and more efficiently (P < .01) but consumed less feed than untreated pigs (P < .01). Increasing the dietary P level improved most of the bone traits. Administration of pST reduced (P < .01) MM strength and percentage ash in the MM and femurs, but it increased (P < .01) femur diameter and wall thickness. Bone strength and percentage ash were reduced in pST-treated pigs fed low dietary P; however, at higher dietary P, these traits were similar to or greater than those in untreated pigs (pST x P, P < .10). Generally, bone traits in pST-treated pigs reached a plateau at higher dietary P concentrations and at higher P intakes compared with those in untreated pigs. These results indicate that pST administration increases the dietary P level that is required to maximize bone traits in finishing pigs.

Animal Feed↗
PubMed1998

Influence of porcine somatotropin on the phosphorus requirement of finishing pigs: II. Carcass characteristics, tissue accretion rates, and chemical composition of the ham.

We investigated the effects of recombinant porcine somatotropin (pST) on the requirement for P to maximize lean tissue accretion and to minimize fat tissue accretion in two experiments using finishing pigs. Corn-soybean meal diets with varying levels of P were fed, and Ca was adjusted to maintain a Ca:P ratio of 1.1:1. In Exp. 1, 96 pigs were fed dietary P concentrations of .35, .45, and .65% from 75 to 109 kg BW. One-half of the pigs were injected daily with 4 mg of pST. Administration of pST increased (P < .05) percentages and accretion rates of lean tissue, bone, skin, water, and protein, but it reduced (P < .05) those of fat tissue and lipid. Increasing dietary P had little effect on chemical composition or accretion rates in untreated pigs, but it increased (P < .05) ash percentage and accretion in pigs treated with pST. Experiment 2 consisted of 66 pigs fed six dietary P concentrations (.35, .50, .65, .80, .95, and 1.10%) from 72 to 114 kg. One-half of the pigs were injected daily with 4 mg of pST. Percentages and accretion rates of lean tissue, bone, skin, water, and protein increased (P < .05) with pST, but those of fat tissue and lipid were reduced (P < .05). Increasing dietary P increased accretion rates of bone and skin (linear, P < .05), lean tissue, water, protein, and ash (quadratic, P <.05), and it reduced (quadratic, P < .05) that of lipid in pigs treated with pST. Dietary P level did not consistently affect percentages or accretion rates of tissues or chemical components in untreated pigs. In most instances, pigs treated with pST required higher dietary P levels and greater daily intakes of P to maximize lean tissue and protein deposition and to minimize fat tissue and lipid accretion than untreated pigs. These results indicate that finishing pigs treated with pST require higher dietary percentages of P to maximize carcass lean deposition as compared with untreated pigs.

Animal Feed↗
PubMed1997

Immunological activities of a lymphocyte mitogen isolated from coenurus fluid of Taenia multiceps (Cestoda).

The purification of a mitogen from Taenia multiceps coenurus fluid has been previously reported. In the present study, this activity, which was independent of endotoxin, stimulated the expression of lymphocyte IL-2 and Fc receptors, enhanced mitotic response to phylohaemogglutinin and concanavalin A and antagonised the previously described suppressive effects of the macrophage modifying fraction of coenurus fluid. The mitogen also increased peritoneal macrophage count and viability, Fc receptor expression and Fc receptor-mediated phagocytosis. The mitogenic activity could be destroyed by a combination of protease and amylase, but not by either enzyme alone. It is suggested that the mitogen forms part of a homeostatic mechanism for the preservation of a balanced host-parasite relationship.

Animals↗
PubMed1997

Characterisation of equine matrix metalloproteinase 2 and 9; and identification of the cellular sources of these enzymes in joints.

The cellular production by resident articular cells and infiltrating inflammatory cells of the gelatinase matrix metalloproteinases (MMP) was investigated by tissue culture methods and analysis of cell supernatants by gelatin zymography. Peripheral blood neutrophils in short term culture produced MMP-9, as did peripheral blood monocytes in culture. Isolated articular chondrocytes in monolayer culture produced both MMP-2 and MMP-9, although articular cartilage maintained as explant culture produced MMP-2 alone. Synovial fibroblasts grown in monolayer culture produced MMP-2 alone, although synovial membrane in explant culture produced both MMP-2 and the active form of MMP-2. Lysis of blood polymorph neutrophils produced large quantities of MMP-9, but lysis of blood monocytes, synovial fibroblasts and articular chondrocytes produced little enzyme indicating that, unlike the other cell types, polymorph neutrophils store MMPs intracellularly. Equine MMP-2 was purified from synovial fibroblast cell culture supernatant, and equine MMP-9 from polymorph neutrophil cell culture supernatant, by gelatin-sepharose affinity chromatography. The 2 enzymes were identified from their molecular weights and by their respective N-terminal amino acid sequences which showed homology with the enzymes from other species. The demonstration that invasive cells and resident articular cells can produce enzymes which are capable of digestion of certain component molecules of the articular cartilage matrix, shows that therapeutic targeting of these enzymes could be a valid proposition in the prevention of cartilage destruction in osteoarthritis.

Amino Acid Sequence↗
PubMed1997

Matrix metalloproteinases 2 and 9 in equine synovial fluids.

Matrix metalloproteinases (MMPs) may be important in the destruction of cartilage seen in equine osteoarthritis and may be detectable in synovial fluid. Synovial fluids were obtained from normal equine joints and from joints of horses with aseptic and septic joint diseases. The total MMP gelatinase enzyme activities were measured by gelatin zymography and image analysis of the gels. The bioactivity of gelatinase in synovial fluid was determined by a gelatin degradation ELISA. Potential MMP-2 & MMP-9 monomer enzyme activities were significantly elevated in both septic and aseptic joint disease synovial fluids in comparison to fluids from normal joints. The dimer form of MMP-9 enzyme activity was significantly elevated in fluids from septic joint disease cases in comparison to fluids form normal joints, but not fluids from horses with aseptic joint diseases. MMP-9 monomer and dimer levels in synovial fluids correlated with the synovial fluid white blood cell count. Using the gelatin degradation ELISA to measure net active gelatinases, significant increases in gelatinase bioactivities were seen in synovial fluids from both aseptic and septic joint disease cases. The enzymes in equine joint diseases were present in a bioactive form, in that they were present in the activated form and present in excess of inhibitors, and could therefore be important in the degradation of articular cartilage in joint disease.

Animals↗
PubMed1996

Serology of Orthopoxvirus cameli infection in dromedary camels: analysis by ELISA and western blotting.

An enzyme-linked immunosorbent assay (ELISA) was developed, together with a Western blotting technique, for the detection of total and IgG and IgM antibodies to camelpox virus (Orthopoxvirus cameli) in camel (Camelus dromedarius) sera and for identifying the seroreactive antigens of the virus. A total of 520 camels from different regions in Libya were tested. The overall seropositivity rate in the examined herds was 9.8%, and varied between herds from 0 to 30%. Two viral antigenic determinants (31 and 35 kDa) were shared by the Western blotting patterns of all the positive camel sera tested. The developed ELISA assay showed ability to differentiate between orthopox and parapoxvirus infections in camels. It is considered that the ELISA technique is justified for serodiagnosis of camelpox in the camel and could be easily modified and usefully applied to other species at risk of poxvirus infection.

Animals↗
PubMed1996

Osteocalcin in canine joint diseases.

Markers of joint disease are much sought after in human and veterinary rheumatology. This study investigated the relationship between markers of bone and cartilage turnover in sera and synovial fluids in naturally occurring canine joint diseases. Osteocalcin (OC) was measured by radioimmunoassay; enzyme-linked immunosorbent assays were used to measure keratan sulphate, chondroitin sulphate, hyaluronan and antibodies to collagen I and II. Dimethylmethylene blue binding assay was used for the estimation of sulphated glycosaminoglycans. Compared to normal dogs significantly higher serum OC was seen in dogs with osteoarthritis (P < 0.005), rheumatoid arthritis (RA) (P < 0.01) and rupture/stretching of cranial cruciate ligament (P < 0.02). Reduced OC was found in RA synovial fluids but this finding is probably of little value as there was too much overlap with normal joint data. Apart from a weak correlation between synovial fluid OC and keratan sulphate, there were generally no correlations between markers of bone and cartilage turnover probably reflecting the lack of any relationship between bone and cartilage metabolism in most canine arthropathies.

Alkaline Phosphatase↗
PubMed1996

Increased metabolism of collagen VI in canine osteoarthritis.

The integrity of joint function depends on both the extracellular matrix and the chondrocytes of articular cartilage. It has been suggested that there is a reciprocal relationship between these two components, which is altered in osteoarthritis. The immunohistochemical distribution of type VI collagen in normal and osteoarthritic canine cartilage was investigated by immunofluorescence and immunoelectron microscopy. Immunogold labelling showed that in normal cartilage type VI collagen was concentrated in the capsule adjacent to the chondrocyte complex. However, in osteoarthritic cartilage, type VI collagen was also observed throughout the cartilage matrix and was greatly increased in the territorial matrix and pericellular capsule surrounding the chondrocytes. Naturally occurring canine osteoarthritis provides a useful model for the study of the human disease, particularly the early stages. The changes in type VI collagen observed in osteoarthritis suggest an attempt at cartilage repair, resulting in the reorganization of the matrix.

Animals↗
PubMed1996

Immunoglobulins of camel (Camelus dromedarius) colostrum.

Immunoglobulins G, M and A were identified in dromedary camel colostra by acid precipitation, gel filtration and fast-protein liquid chromatography (ion exchange). Heavy and light chains were identified by polyacrylamide gel electrophoresis and Western blotting. IgG subclasses (IgG1, IgG2 and IgG3) were isolated by DEAE ion-exchange chromatography and shown to have different electrophoretic mobilities. Cross-reactivity of camel IgA with IgA of other species was determined by enzyme-linked immunosorbent assay (ELISA). Most of the immunoglobulin content was IgG, but a molecule identifiable as IgA was detected and purified. It would appear that in the camel, as in cattle, IgG is the major secretory immunoglobulin of colostrum.

Animals↗
PubMed1996

Macrophage modifying factor secreted by the tetrathyridia of Mesocestoides corti (Cestoda): monoclonal antibody to the modifying factor antagonizes its immunological activity.

Immunomodulation of macrophage activity by in vitro secretions of Mesocestoides corti has been previously demonstrated. The modifying activity secreted by M. corti had the effect of reducing the normal accessory function of macrophages in a Con-A-activated lymphocyte proliferation assay. This paper describes the purification of the modifying activity by FPLC techniques and the generation of a monoclonal antibody (MoAb) to this molecule in mice. The MoAb bound immunomodulatory FPLC fractions of M. corti in an ELISA. When MoAb was applied in conjunction with immunomodulatory parasite secretions to macrophages in vivo or in vitro, the modifying effect of the secretions was abolished. This profound effect of the MoAb should help to elucidate the mechanisms by which metacestode parasites avoid host immune responses and may enable therapeutic intervention.

Adjuvants, Immunologic↗