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Biomedical subjects

J D Perry

Publications and source records attributed to J D Perry.

At least 91 records · Page 5Linked to original sources
PubMed1988

Reduction of the surface charge of blood polymorphonuclear cells by rheumatoid sera and heat induced aggregated human IgG (HAGG).

Cell electrophoresis identifies two main subpopulations of blood polymorphonuclear cells (PMNs), which in terms of the speed of their anodic migration are referred to as the fast and slow population. When blood PMNs from normal healthy subjects were incubated in medium containing 20% RA serum there was a decrease in the percentage of fast cells with a corresponding increase in the slow population that was directly related to the levels of circulating immune complexes present in the sera. Similar results were obtained when using heat induced aggregated human IgG (HAGG) or Candida albicans instead of RA serum. The 'slowing' effect of HAGG, which was transient and time dependent, appeared to be due to its internalisation by the PMNs. These results suggest that in RA the large number of blood PMNs with a low surface charge (i.e., the slow population) may arise as a result of the constant interaction of these cells with circulating immune complexes.

Antigen-Antibody Complex↗
PubMed1988

Rapid conventional scheme for biochemical identification of antibiotic resistant enterobacteriaceae isolates from urine.

Six conventional biochemical tests were combined to produce an identification scheme. These tests included decarboxylation of lysine and ornithine, fermentation of glucose and cellobiose, indole production and urease production. Three hundred antibiotic resistant coliforms from urine specimens were tested by this scheme and also by the API 20E for comparison. Two hundred and seventy nine (93%) of organisms were correctly identified using the six tests, 17 (5.7%) were referred for further study, and four (1.3%) were misidentified. It is concluded that this combination of tests provides an inexpensive, accurate, and rapid tool for identification.

Bacteriological Techniques↗
PubMed1987

The effects of adherent cells on measurement of the hyper-responsiveness of rheumatoid B lymphocytes to Epstein-Barr virus.

Rheumatoid peripheral blood mononuclear cells show an increased responsiveness to superinfection with Epstein-Barr virus (EBV). We have investigated the role of adherent cells in this hyperresponsiveness using two different methods of adherent cell depletion. Depletion of adherent cells from both rheumatoid and normal mononuclear cells, using either dextran bead columns or plastic petri dishes, produced inconsistent changes in the response of autologous non-adherent cells to EBV. The addition of supernatants of cultured rheumatoid adherent cells also produced an inconsistent change in response although normal adherent cell supernatants increased the responsiveness of autologous non-adherent cells to EBV. The inconsistencies observed are discussed with respect to adherent cell subpopulations present in rheumatoid and normal peripheral blood mononuclear cell preparations when using recognized methods of adherent cell depletion.

Arthritis, Rheumatoid↗
PubMed1987

Enhanced chemotaxis of monocytes in rheumatoid arthritis.

The migration responsiveness to zymosan-activated serum of monocytes isolated from the blood of 19 rheumatoid arthritis (RA) patients and 19 healthy subjects was measured. The chemotaxis of RA monocytes, but not their random migration or chemokinesis, was significantly greater than that of monocytes from normal healthy subjects. To investigate whether this effect were due to soluble factors present in RA blood, the migration of monocytes from healthy subjects was assessed in the presence of sera from 28 RA patients and 21 healthy subjects. The inability of RA sera to modify the migration of normal monocytes implies that the enhanced chemotaxis of RA monocytes is attributable to the inherent property of these cells and not due to the activity of serum modifying factors.

Arthritis, Rheumatoid↗
PubMed1987

Adherence of rheumatoid polymorphonuclear cells (PMNs) to cultured endothelial cell monolayers.

Blood polymorphonuclear cells (PMNs) from 40 patients with rheumatoid arthritis (RA) and 40 normal subjects were incubated with confluent cultures of porcine aortic endothelium and their adherence assessed by either a microscopic or radiometric enumeration assay. There was no difference between the number of rheumatoid and control PMNs adhering. The synovial fluid PMNs from patients with RA were less adherent than their paired blood samples when autologous serum was present in the incubation medium and more adherent when serum was absent. Most of the RA sera tested inhibited the adhesion of normal PMNs, an effect that was not due to an increase in PMN aggregation. A similar inhibition was seen with sera obtained from patients with Felty's syndrome. These findings suggest that there is no intrinsic difference between the adhesiveness of rheumatoid PMNs and normal PMNs but that there are soluble factors present in RA serum which inhibit the attachment of normal PMNs to vascular endothelium.

Arthritis, Rheumatoid↗
PubMed1987

Rheumatoid blood decreases the adherence of polymorphonuclear cells (PMNs) to cultured endothelium.

Rheumatoid sera and plasma inhibited the adherence of normal blood polymorphonuclear cells (PMNs) to cultured porcine endothelium. This inhibition of adhesion was not seen when PMNs were treated with the plasma or serum from normal subjects or patients with other inflammatory arthropathies. The abrogation of PMN adherence was directly related to the levels of circulating immune complexes and was not dependent upon the type of anti-inflammatory therapy that the patients were receiving nor on any of the recorded clinical parameters. A similar inhibition of adhesion was seen with heat induced aggregated human IgG (HAGG) provided that serum was present in the culture medium. In view of these results we propose that circulating immune complexes in RA may have a significant role in controlling the interaction of PMNs with vascular endothelium and in perpetuating the entry of these cells into the synovial fluid of the inflamed joints.

Antigen-Antibody Complex↗
PubMed1986

HLA antigens in palindromic rheumatism and palindromic onset rheumatoid arthritis.

Fifty patients who presented with typical palindromic rheumatism of at least 6 months' duration were tissue-typed for HLA A, B, C antigens. DR typing was also performed but was not possible for technical reasons in three patients. Twenty-three patients who had progressed to definite or classical rheumatoid arthritis (RA) after a mean interval of 5 years were compared with 20 patients whose palindromic attacks had persisted over a similar period. Both groups showed a significantly higher frequency of DR4 antigen than a control population. The RA group also showed an increased frequency of DR1. There was no significant difference in the frequency of DR4 or any other DR antigen between the two patient groups. The frequency of B27 antigen was significantly higher in the palindromic group compared with the controls. It is suggested that although DR4 may be associated with a tendency to inflammatory joint problems, environmental or other unrelated genetic factors may be more important in determining the progression of palindromic rheumatism to RA.

Arthritis, Rheumatoid↗
PubMed1986

Scanning electron microscopy of rheumatoid arthritis peripheral blood polymorphonuclear leucocytes.

Peripheral blood polymorphonuclear leucocytes (PMNs) were isolated from six normal individuals and from 27 patients with rheumatoid arthritis (RA) by the Ficoll-Hypaque rapid single step centrifugation technique, fixed in suspension, and examined by scanning electron microscopy (SEM). In addition, four of the preparations from normal individuals and eight from patients with RA were examined by transmission electron microscopy (TEM). Most PMNs in preparations from normal subjects were spherical, unpolarised, and had their surface membrane elaborated into irregular ridges and small ruffles; they contained few phagocytic vacuoles and large numbers of electron dense primary and secondary granules. A minority of the cells were non-spherical, polarised, and had portions of their surface membrane elaborated into ruffled pseudopodia. In contrast, preparations of RA PMNs frequently contained fewer unpolarised PMNs and a higher number of polarised PMNs than did preparations of normal PMNs. Some preparations of RA PMNs also contained substantial numbers of spherical cells whose surface was covered mainly by bulges and blebs. Concurrent examination by TEM showed that RA PMNs frequently contained more phagocytic vacuoles and fewer electron dense primary and secondary granules than normal PMNs. The morphological and ultrastructural changes seen in RA PMNs resembled those which normal PMNs are known to undergo on exposure to C5a in vitro, during adherence to endothelial cells in vivo, or during phagocytosis in vivo or in vitro. Our observations, therefore, provide a useful morphological correlation to those in vitro studies in which differences in the functional activity of RA and normal PMNs have been shown. The possibility that the difference seen between RA and normal PMNs is artefactual and does not represent the genuine in vivo states of these cells is discussed.

Adult↗
PubMed1985

Do vitamin D supplements improve the physical capabilities of elderly hospital patients?

A randomized double-blind controlled trial of the effect of vitamin D supplementation on the abilities of elderly hospital patients to carry out basic activities of daily life is described. Those patients included in the trial had plasma 25-hydroxyvitamin D concentrations which were low or low normal as judged by the normal range in young adults. After 2 to 9 months on the trial there was no significant difference in the performance of the control and treatment groups.

Activities of Daily Living↗
PubMed1984

Centrifugation of normal and rheumatoid arthritis blood on Ficoll-Hypaque and Ficoll-Nycodenz solutions.

Attempts to use the rapid single-step Ficoll-Hypaque centrifugation procedure for the purification of mononuclear and polymorphonuclear leucocytes from the blood of normal individuals and rheumatoid arthritis patients have sometimes been unsuccessful, largely because the erythrocytes would not sediment through the centrifugation medium. Re-evaluation of the factors (e.g. Ficoll concentration, temperature, and ratio of the diatrizoate salts) which affect these separations showed that under our conditions it was advantageous to use a medium with a lower viscosity (Ficoll concentration) and/or a higher osmotic strength (increased sodium diatrizoate: meglumine diatrizoate) than had been recommended previously (Ferrante and Thong, 1978; 1980; Ferrante et al., 1982). Higher osmotic strength media must be used for separating the components of blood from rheumatoid arthritis patients than from normal individuals because rheumatoid arthritis erythrocytes have a lower buoyant density than normal erythrocytes.

Arthritis, Rheumatoid↗