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R R Coombs

Publications and source records attributed to R R Coombs.

At least 37 records · Page 2Linked to original sources
PubMed1987

Isolation of low-frequency class-switch variants from rat hybrid myelomas.

Class-switch variants have been isolated from rat-rat hybrid myelomas by sib selection using a simple assay based on red cell-labelled antiglobulins. The variants detected are consistent with the gene order deduced from molecular cloning. They appear to arise spontaneously at a rate approximately ten-fold lower than for mouse cell lines but the rate of switching back to the parental isotype is substantial in comparison. An IgG2b variant antibody having the same specificity as CAMPATH-1 for human lymphocytes and monocytes is active in antibody-dependent cell-mediated killing (unlike the parental IgG2a) and may prove to be a valuable therapeutic antibody for immunosuppression and treatment of leukaemia and lymphoma.

Animals↗
PubMed1987

Detection of ecto-5'-nucleotidase on rat B and T lymphocyte subpopulations using a monoclonal antibody in rosetting reactions.

A mouse monoclonal antibody to rat 5'-nucleotidase (5N 4-2 McAb) was used in the direct anti-determinant rosetting reaction (DARR) to demonstrate the ecto-5'-nucleotidase molecule in preparations of rat lymphocytes. Results indicated that 35.5 +/- 7.5% of peripheral blood lymphocytes (PBL), 37.3 +/- 4.8% of lymph node cells (LN) and 37.0 +/- 8.5% of spleen lymphocytes expressed the 5N 4-2 antigen. Depletion studies and mixed rosetting reactions (MRR) showed that the 5N 4-2 antigen was mainly expressed on rat T lymphocytes rather than on B lymphocytes: In fact 59.6 +/- 3.2% (in PBL), 76.5 +/- 0.6% (in LN) and 67.1 +/- 1.3% (in spleen) of T lymphocytes exhibited the 5N 4-2 antigen compared to only 26.5 +/- 2.6% (in PBL), 34.0 +/- 2.1% (in LN) and 46.1 +/- 12.0% (in spleen) of B lymphocytes. As expected a strong association was found between the expression of 5N 4-2 antigen and 5'-nucleotidase enzyme activity on lymphocytes. Both 5N 4-2 positive cells and enzyme activity were preferentially exhibited in the T lymphocyte subpopulation, and 92% of the enzyme activity was observed in a 5N 4-2 antigen positive subpopulation.

5'-Nucleotidase↗
PubMed1987

Detection of Chlamydia psittaci from various animal species by reverse passive haemagglutination.

A reverse passive haemagglutination test (RPH) has previously been developed to detect the genus-specific antigen of Chlamydia. Clinical samples were obtained from various sites of different animal species. The RPH test detected chlamydial antigen from clinical cases of conjunctivitis in cats, abortion in sheep and psittacosis in birds. Although not as sensitive as cell culture isolation, this test has the advantages of rapidity and of detecting antigen from dead chlamydiae.

Abortion, Veterinary↗
PubMed1987

Idiotype-anti-idiotype interactions of VHIX-coded anti-progesterone and anti-arsonate antibodies. Comparison of passive haemagglutination and radioimmunoassays.

The reactivity and specificity of polyclonal and monoclonal anti-idiotypic antibodies raised against monoclonal anti-progesterone and anti-arsonate antibodies have been studied by solid phase radioimmunoassay (RIA) with immobilized idiotype and by passive haemagglutination with idiotype-coupled red cells. The sensitivity of the two methods was comparable, though some cross-reactions were only detected by RIA. Passive haemagglutination was found to be especially suitable in screening for monoclonal anti-idiotypes in hybridoma supernatants and ascites, and had advantages over RIA in detection of syngeneic anti-idiotypes. Demonstration of binding site-associated idiotopes was possible by haemagglutination inhibition. RIA and haemagglutination were used to investigate the idiotypic relationships between BALB/c antiprogesterone and anti-arsonate monoclonal antibodies which share heavy chains encoded by VHIX variable region genes.

Amino Acid Sequence↗
PubMed1987

Antigenic stimulation with proteins of cow's milk via the oral route in guinea pigs and rats. 1. Measurement of antigenically intact beta-lactoglobulin and casein in the gastrointestinal contents of duodenum, jejunum and ileum.

Guinea pigs and rats drinking cow's milk ad libitum have had the contents of their stomach, duodenum, jejunum and ileum examined for antigenically native, undigested beta-lactoglobulin and casein. The whey protein was present, in every case, in higher concentration and could be found, although in decreasing amounts, right down to the ileum. In the rat, casein could not be shown at any level of the small intestine and in the guinea pig only at the level of the duodenum.

Administration, Oral↗
PubMed1987

Antigenic stimulation with proteins of cow's milk via the oral route in guinea pigs and rats. 2. Antibodies to beta-lactoglobulin secreted into the alimentary canal and serum.

The intestinal contents of guinea pigs and rats on a milk-drinking diet were examined for mucosal-secreted antibody to beta-lactoglobulin. Assay of the immunoglobulin content of duodenum, jejunum and ileum of the guinea pig gave geometric means of 70, 90 and 95 micrograms/ml. In the rat, where isotype-specific antiglobulin reagents were available, similar figures were obtained but it could be shown that the vast majority was IgA. Passive haemagglutination titres up to 1,000 of secreted anti-beta-lactoglobulin antibody (resistant to the endogenous proteases in the intestinal contents) were measured in guinea pigs. Fifteen days after cessation of milk-drinking, the antibody had dropped to undetectable levels. No such antibody could be shown in rats. Rats also failed to develop detectable serum antibody whereas, the guinea pigs had passive haemagglutination titres in the order of 16,000.

Administration, Oral↗
PubMed1987

Tolerance to orally induced anaphylactic sensitisation to cow's milk proteins and patency of the intestinal mucosa in the neonatal guinea pig.

Guinea pigs fed cow's milk within 2 days of birth may acquire tolerance to anaphylactic sensitisation to cow's milk proteins. Appreciable amounts of beta-lactoglobulin may be detected in their blood, in contrast with animals receiving cow's milk later than this age. Uptake of beta-lactoglobulin from the gut to circulation ceases after the 6th postnatal day. These findings could be relevant to cot death in the human infant should the anaphylactic hypothesis be substantiated.

Anaphylaxis↗
PubMed1986

Direct antibody rosette-forming reactions using monoclonal markers of lymphocyte subpopulations. Methodology and applications illustrated by investigations with rat pan-T antibodies of the CAMPATH series.

A sensitive direct antibody rosette assay has been developed for the detection of antigens on the lymphocyte cell membrane. Indicator cells for rosette tests were prepared by chromic chloride coupling of rat or mouse monoclonal IgG or IgM anti-lymphocyte antibodies to untreated or trypsinized bovine red blood cells. The monoclonal antibodies used were reactive with a range of cell surface markers which identify various lymphocyte subpopulations, including T cell antigens, HLA class II (Ia-like antigens), Leu-7 (HNK-1) and VEP 13, a determinant of Fc gamma receptors on large granular lymphocytes. Results obtained by direct rosette formation correlated well with those of parallel tests using indirect immunofluorescent antibodies staining. Several applications of the direct antibody rosetting procedure are described in further investigations with a series of pan-T monoclonal (CAMPATH) antibodies. These include the morphological examination of antibody-binding cells in cytocentrifuge smears, the separation of lymphocyte subsets by density gradient centrifugation, and the use of a rosette inhibition assay to identify monoclonal antibodies binding to the same (or closely associated) epitopes of the lymphocyte cell membrane.

Animals↗
PubMed1986

Experimental induction of rheumatoid factor and joint lesions in rabbits after intravenous injections of killed bacteria.

Rabbits receiving repeated intravenous injections of killed bacteria (Escherichia coli or Bacillus subtilis) developed IgM rheumatoid factor which reacted with autologous heat-aggregated IgG. In addition, 5/7 'Old English' and 7/8 'Sandy Lop' rabbits receiving killed E. coli developed rheumatoid-like synovial lesions. 'Old English' rabbits developed lesions of a more severe nature. Three of eight 'Sandy Lop' rabbits injected with killed B. subtilis had high levels of rheumatoid factor but only mild joint lesions.

Animals↗
PubMed1986

Synovitis associated with serum IgM rheumatoid factor arising spontaneously in 'Old English' rabbits.

This paper reports the spontaneous development of synovitis in 'Old English' rabbits concurrent with serum IgM rheumatoid factor. Female rabbits developed lesions at a higher incidence than males (42% compared with 17%) and the pathology was of a more severe nature. In the female rabbits synovitis was associated with concurrent high serum IgM rheumatoid factor and high serum antibody levels to Pasteurella multocida. There was no histological evidence that the joints were directly infected.

Animals↗
PubMed1986

Comparison of the arthritogenic properties of dietary cow's milk, egg albumin and soya milk in experimental animals.

The arthritogenic effect of dietary cow's milk, egg albumin and soya milk were compared in Old English rabbits. The 12-week cow's milk feeding regimen produced the highest incidence of significant joint lesions. Lesions were evident but mild at 5 weeks and the synovitis had resolved by 32 weeks. It is suggested that the transient nature of the synovitis may be due to the development of specific secretory IgA antibodies which were detectable in faecal pellet extracts. Sandy Lop rabbits were less susceptible to the arthritogenic effect than were Old English rabbits. Dietary ovalbumin was less arthritogenic than cow's milk despite high titres of serum and synovial fluid antibodies and immune complexes. The rabbits were 'tolerant' to dietary soya due probably to pre-existing levels of soya protein in their diet. Lewis and Wistar strain rats, CBA, Balb/c and C57/BL6 mice fed on cow's milk for 3 months did not develop serum antibodies or synovial lesions. It is suggested that this allergic synovitis is not a model for early rheumatoid joint disease because of the transience of the lesions and lack of stimulation of rheumatoid factor. It may well, however, be a model for the arthralgia seen in patients with certain food allergies.

Animals↗
PubMed1986

Autologous granulocyte scanning of painful prosthetic joints.

To detect sepsis in the painful joint, autologous granulocytes labelled with indium-111 were used to scan 60 patients with 74 prosthetic joints. All 18 patients with confirmed sepsis had positive scans, that is, migration of granulocytes into the region of the prosthesis. Of the 22 sterile arthroplasties 20 had negative scans. In 34 cases there was good correlation between the clinical impression and the result of the scan. We suggest that indium granulocyte scintigraphy is a reliable method of detecting an infected prosthesis.

Bacterial Infections↗
PubMed1986

Indium-granulocyte scanning in the painful prosthetic joint.

The value of indium-111-labeled granulocyte scanning to determine the presence of infection was assessed in 50 prosthetic joints (41 of which were painful) in 40 patients. Granulocytes were obtained from the patients' blood and labeled in plasma with indium 111 tropolonate. Abnormal accumulation of indium 111 in the region of the prosthesis was noted. Proven infection occurred in 11 prostheses, and all of the infections were detected by indium-111-labeled granulocyte scanning. Nineteen were not infected (including nine asymptomatic controls) and only two produced false-positive scans. This represents a specificity of 89.5%, sensitivity of 100%, and overall accuracy of 93.2%. These results compare favorably with plain radiography. There was no radiologic evidence of infection in three of the infected prostheses, and 10 of the noninfected prostheses had some radiologic features that suggested sepsis. We conclude that indium-granulocyte scanning can reliably detect or exclude infection in painful prosthetic joints and should prove useful in clinical management.

Granulocytes↗
PubMed1985

Fc gamma-receptor-bearing, non-B lymphocytes in human peripheral blood: cytophilic immunoglobulin binds almost exclusively to large granular lymphocytes.

Cytophilic IgG (CYT-Ig) has previously been reported to bind to both the "TG" (E+, Fc gamma R+) and "L" (E-, Fc gamma R+) subsets of non-B lymphocytes in human peripheral blood. Present investigations show that IgG-binding cells, as detected by a sensitive antiglobulin rosetting reaction, are contained almost entirely within the large granular lymphocyte (LGL) subpopulation, and that fewer than 5% of other non-B lymphocytes acquire IgG from serum. Cell membrane-bound IgG sterically blocks the reaction of LGL with sheep red blood cells and therefore influences the proportions of these cells characterized as TG (E+) or L (E-) lymphocytes. Although the majority of TG lymphocytes are LGL, a further subpopulation of E+, Fc gamma R+ cells are detectable under particular test conditions. Unlike LGL, these lymphocytes do not react with rabbit IgG-coated ox RBC (EAG) in saline, but will form EAG rosettes when the reaction is enhanced in the presence of Ficoll. These Fc gamma R+ cells are mostly of typical small-lymphocyte morphology and do not bind detectable amounts of CYT-Ig, nor do they express the monoclonal antibody-defined VEP 13 determinant associated with Fc gamma R on LGL.

Antibody Affinity↗
PubMed1985

Radiolucent plastic in gunshot wounds.

We present two patients who suffered a total of three close-range gunshot wounds. In each injury plastic shot-retaining wadding had been carried deep into the tissues but this was not apparent on the initial radiographs. The presence of such plastic wadding must be considered in all such wounds.

Adult↗