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Biomedical subjects

S J Thompson

Publications and source records attributed to S J Thompson.

At least 91 records · Page 5Linked to original sources
PubMed1993

Comparison between the protective effects of mycobacterial 65-kD heat shock protein and ovomucoid in pristane-induced arthritis: relationship with agalactosyl IgG.

The IgG of patients with rheumatoid arthritis and mice with pristane induced arthritis (PIA) tends to lack the terminal galactose normally on the conserved N-acetylglucosamine linked beta 1-2 to mannose in IgG. The terminal N-acetylglucosamine (GlcNAc) residues of oligosaccharides on agalactosyl IgG may be an important component of the action of these glycoforms. Here, administration of ovomucoid, a glycoprotein rich in terminal GlcNAc, before pristane injection was found to reduce the incidence of PIA. This observation is the second report of an intraperitoneally administered antigen that reduces the incidence of PIA, mycobacterial 65-kD heat shock protein (hsp65) being the first. The suppressive effect of ovomucoid was not transferred from protected to naive recipients by spleen cells at the dose tested. By contrast, transfer of spleen cells from hsp65-protected mice to naive recipients conferred protection and this protection may be antibody-mediated. It is considered that ovomucoid and hsp65 protect against the development of PIA by different mechanisms.

Animals↗
PubMed1993

Review: extraaural health effects of chronic noise exposure in humans.

Thirty-one epidemiologic studies published in the English literature since 1980 were reviewed to integrate the findings on effects of chronic industrial and traffic noise exposure on circulatory and cardiovascular diseases. Methodologic issues relevant to quantifying noise-induced risk are discussed. Although there has been some improvement over the decade, the quality of the research remains low. Cross-sectional studies continue to dominate. Studies to date show contradictory results, neither confirming nor invalidating the hypothesis that persons with prolonged exposure to high noise levels have an increased risk of high blood pressure and cardiovascular disease. Prevalence ratios for hypertension between high and low noise groups range from 0 to 3.1. The more methodologically rigorous studies report the lower associations. Differences in mean blood pressures detected have been relatively small, ranging from 0-10 mm Hg. No consistent pattern of findings on cardiovascular effects other than blood pressure has been reported. It is concluded that the quality of the research remains inadequate or inadequately reported for quantifying noise-induced risk. Prospective studies whose design accounts for potential confounding variables and effect modifiers are required before useful inferences may be drawn.

Arousal↗
PubMed1993

Prevention of pristane-induced arthritis by the oral administration of type II collagen.

This is the first demonstration of a role for type II collagen in pristane-induced arthritis. Pretreatment with soluble type II collagen either lowers or raises the subsequent incidence and severity of pristane-induced arthritis. These effects are dependent upon both the dose and route of administration of the soluble type II collagen. Increasing doses of orally administered type II collagen lowered both the incidence and severity of pristane-induced arthritis. Conversely, increasing doses of intraperitoneally administered type II collagen increased both the incidence and severity of arthritis. This exacerbation of pristane-induced arthritis was accompanied by elevated B- and T-cell responses to type II collagen. These findings highlight the importance of the site at which antigen is encountered in influencing subsequent immune responses and extend the observations of the use of orally administered antigens to ameliorate experimental autoimmunity.

Administration, Oral↗
PubMed1992

Role of delayed feeding and of feeding increments in necrotizing enterocolitis.

In spite of a number of studies on necrotizing enterocolitis, there remains controversy concerning prevention regimens, especially with regard to enteral alimentation. This report is of a matched case-control study of the relationship of necrotizing enterocolitis to timing of first feeding, size of feeding volumes and increments, and a risk factor index in 59 case patients with necrotizing enterocolitis and 59 matched control patients. Comparison with control patients showed that case patients were fed earlier, received full-strength formula sooner, and received larger feeding volumes and increments. More highly stressed infants, as measured by the risk index, were more vulnerable to larger feeding increments. Among case patients there was significant correlation of age at first feeding and age at diagnosis (p < 0.0001) even after control for birth weight and risk index score, indicating that delayed feeding was related to delayed onset of disease. These analyses support the theory that earlier, more rapid feeding places stressed infants at greater risk for the development of necrotizing enterocolitis, and that infants with more severe respiratory problems are more vulnerable to such feeding practices.

Birth Weight↗
PubMed1992

Agalactosyl IgG in pristane-induced arthritis. Pregnancy affects the incidence and severity of arthritis and the glycosylation status of IgG.

The effect of pregnancy on the incidence and severity of pristane-induced arthritis was examined along with the glycosylation status of IgG during the ante-natal and post-partum periods. It was found that pristane-induced arthritis is prevented by pregnancy. In addition, the levels of agalactosyl IgG fall during pregnancy but rise to greater than normal within a few days of parturition, before resetting towards the norm shortly afterwards. Interestingly, the level of agalactosyl IgG correlates with the severity of arthritis. As previously reported IL-6 may be an important factor, not necessarily the only one, in the production of agalactosyl IgG. Here it is clearly demonstrated that the kinetics of IL-6 activity post-pristane injection parallels the kinetics of agalactosyl IgG production. In addition, the overshoot in agalactosyl IgG levels immediately post-partum coincides with a burst in IL-6 activity. It is considered that these changes in IgG glycoform levels, or the factors which control them, may be related to the mechanisms underlying prevention/remission of arthritis during pregnancy.

Animals↗
PubMed1992

P53 and Ki-67 immunoreactivity in human prostate cancer and benign hyperplasia.

Mutation of the p53 gene is one of the commonest genetic abnormalities found in solid human tumours. This gene is probably concerned with the control of cellular proliferation and in view of this we carried out a study of human prostate cancer and benign prostatic hyperplasia, comparing the expression of mutated p53 with measurement of growth fractions as assessed by staining with Ki-67. A series of 29 patients with prostate cancer (CaP) were compared with 34 men with benign hyperplasia (BPH); 22 of 29 prostate cancers (76%) contained Ki-67 immunoreactivity compared with 10 of 34 (29%) BPH. With respect to p53 staining, significantly more prostate cancers (17%) were stained than BPH (0%). The mean Ki-67 score in cancers positive for p53 (4.3%) was greater than that found in cancers negative for p53 (1.2%), but no statistically significant relationship was found between tumour grade and Ki-67 staining. The use of Ki-67 and p53 staining may allow identification of tumours with a higher rate of cell growth and may permit development of prognostic factors.

Aged↗
PubMed1992

Relationship between interleukin 6, agalactosyl IgG and pristane-induced arthritis.

IL-6 titres in sera and peritoneal exudate fluids (PEF) derived from pristane injected DBA/1 and CBA/Igb mice were measured. Arthritic DBA/1 mice had significantly higher serum IL-6 titres than nonarthritic or normal mice at 160 days post pristane injection. By contrast, although both arthritic and non-arthritic CBA/Igb mice had higher serum IL-6 titres than normal mice, there was no significant difference in serum IL-6 titre between these two groups at day 200-230. In both strains of mice, the IL-6 titres in PEF were more than 10 times serum levels regardless of arthritis. As previously reported for CBA/Igb mice, agalactosyl IgG levels are raised in pristane injected DBA/1 mice and the percentage is higher in arthritic animals than that in non-arthritic mice. An association between serum agalactosyl IgG levels and PEF IL-6 in pristane injected DBA/1 was demonstrated. Moreover, the injection of recombinant IL-6 into normal mice increased their serum agalactosyl IgG levels. However, it is considered that IL-6 is not the only factor involved in the production of agalactosyl IgG.

Animals↗
PubMed1992

Mediators of joint swelling and damage in rheumatoid arthritis and pristane induced arthritis.

Joint swelling and tenderness in rheumatoid arthritis (RA) probably result from IgG aggregates activating complement with the consequent attraction of polymorphonuclear leucocytes (PMNs) and the liberation of their granule enzymes such as kininogenases. By contrast IL-1 and TNF are the major stimulants of cartilage and bone loss although other agents contribute. The fundamental drive for the production of these mediators is unknown but a role for heat shock proteins is suggested from work on pristane induced arthritis.

Animals↗
PubMed1992

Differential effects of immunisation with mycobacterial 65 kD heat shock protein on two models of autoimmunity.

The effects of preimmunisation with the 65 kD mycobacterial heat shock protein (hsp65) on 2 murine models of autoimmunity were compared. Experimental autoimmune haemolytic anaemia (AIHA) can be provoked in mice by repeated injection with rat red blood cells (RBC). In this model, preimmunisation with hsp65 10 days before induction of disease resulted in a partial, but significant, reduction in RBC-bound autoantibody levels measured by Coombs' test. However, preimmunisation with human IgG (hIgG) was associated with a similar suppressive effect. Administration of neither hsp65 nor hIgG affected the direct or indirect anti-rat agglutinin titres of mice subsequently injected with rat RBC. Injection of hsp65 or hIgG prior to induction of AIHA elicited the production of IgG antibodies against the respective immunogen, as judged by enzyme-linked immunosorbent assays. In contrast to the results in experimental AIHA, pristane-induced arthritis (PIA) was effectively prevented by preimmunisation with hsp65, but not with hIgG. It is considered that, whilst hsp65 injection may slightly reduce subsequent anti-RBC autoantibody production in AIHA by antigenic competition, such a mechanism cannot account for the substantial protection against PIA afforded by hsp65 preimmunisation. We suggest that the high, sustained production of anti-hsp65 antibodies observed in mice given hsp65 and pristane may play a role in specifically suppressing arthritogenic immune responses in PIA.

Anemia, Hemolytic, Autoimmune↗
PubMed1992

An epidemiologic study of smoking and primary infertility in women.

OBJECTIVE: To determine the relationship between cigarette smoking and primary female infertility. DESIGN: Retrospective, case-control study. SETTING: Population-based and randomly selected from eight geographic areas in the United States. PARTICIPANTS: Women, 20 to 54 years of age, who were randomly selected to serve as the control group of the Cancer and Steroid Hormone Study were used for this study. Within this group, there were 483 women who were classified as having experienced primary infertility and 2,231 women eligible to serve as controls. Primary infertility, defined as 24 consecutive months of unprotected intercourse without conception, was documented from a calendar of each women's reproductive and contraceptive history. RESULTS: Smoking one pack of cigarettes per day (odds ratio = 1.36) and starting to smoke before 18 years of age (odds ratio = 1.30) were significantly associated with increased risk of infertility. Life table and proportional hazards analysis indicated that smoking did not significantly increase the time required to conceive among infertile women. CONCLUSIONS: Number of cigarettes smoked and age when the women began smoking contributed to infertility in this study. It is reasonable, therefore, to recommend that women stop smoking when they are attempting to become pregnant.

Adult↗
PubMed1991

Influence of disodium aurothiomalate on the activities of xanthine dehydrogenase and xanthine oxidase in endothelial cells.

The effect of aurothiomalate in modulating the conversion of xanthine dehydrogenase to its superoxide producing oxidase form in rat and human liver cytosolic preparations has been investigated. Low concentrations (10(-8)-10(-5) mol.dm-3) of this second-line agent were found to inhibit the conversion of the dehydrogenase to its corresponding oxidase form. High concentrations (10(-4) mol.dm-3), however, accelerated this conversion. It is possible that the influence of aurothiomalate on the relative proportions of xanthine dehydrogenase and xanthine oxidase is a reflection of the gold(I) blockage of critical thiol(ate) or sulphido ligands present in this enzymatic system. These effects may form the basis of aurothiomalate's anti-proliferative action on endothelial cells.

Animals↗
PubMed1991

Modulation of pristane-induced arthritis by mycobacterial antigens.

Several prominent mycobacterial protein antigens involved in antibody and T cell responses have been identified as members of highly conserved heat shock protein families. In particular, immune responses to the mycobacterial 65 kD heat shock protein (hsp65) have been implicated in the pathogenesis of autoimmune diseases both in experimental animal models and in man. Additionally, hsp65 has been shown to modulate the course of autoimmune disease in such experimental animal systems. In this report, we have examined the synthesis of heat shock proteins by a fast growing mycobacterial strain, M. vaccae, in heat stressed cultures and used the pristane induced arthritis model to investigate the immunoprophylactic and immunotherapeutic potential of heat killed M. vaccae. Heat shock of M. vaccae cultures at 48 degrees C demonstrated a 43-fold increase in hsp65 over that expressed at 37 degrees C. It is therefore suggested that heat killed M. vaccae contains sufficient hsp that can be presented in the context of appropriate adjuvant properties for use as an effective immunomodulatory agent. Immunisation experiments with M. vaccae revealed that protection or exacerbation of pristane induced arthritis was dependent on the dose (given in an oil or aqueous suspension), route and time of immunisation. In addition, it was demonstrated that the development of arthritis correlated with high levels of agalactosyl IgG and that "protected" animals had significantly depressed levels.

Animals↗
PubMed1991

Cellular and humoral reactivity pattern to the mycobacterial heat shock protein hsp65 in pristane induced arthritis susceptible and hsp65 protected DBA/1 mice.

We have analysed the cellular and humoral immunity to the mycobacterial 65 kD heat shock protein (hsp65) in groups of DBA/1 mice with arthritis induced by intraperitoneal injection of the mineral oil pristane. Here we confirm that DBA/1 mice are highly susceptible to pristane induced arthritis (PIA) and demonstrate that the incidence of arthritis can be modulated by either pretreatment with low dose irradiation or by preimmunisation with recombinant hsp65. Global cellular responses to antigens such as BSA or type II collagen were not enhanced or impaired within groups of arthritic (A) or non-arthritic (NA) mice. However, the cellular response to hsp65 in arthritic animals preimmunised with the 65 kD antigen was significantly elevated in comparison to hsp65 preimmunised mice that were resistant to the induction of disease. On the contrary, the level of hsp65 specific antibodies was much high in NA animals than in PIA mice. CBA/Igb mice are partially susceptible to the induction of PIA. We have previously reported that arthritic CBA/Igb mice have both elevated cellular and humoral reactivity to hsp65. Although a central pivotal role for hsp65 has been postulated in autoimmune diseases these results indicate that there is no simple relationship between the pathogenesis of PIA and immune responses to hsp65.

Animals↗
PubMed1990

Autoimmune reactions to heat-shock proteins in pristane-induced arthritis.

The development of arthritis induced in mice by intraperitoneal injection of the non-antigenic mineral oil, 2,6,10,14-tetramethylpentadecane (pristane), was shown to depend on an intact immune response possibly to a heat-shock protein (hsp) in the synovium. Initial experiments suggested that some crucial event in the development of arthritis takes place early after pristane injection. First, irradiated pristane-treated mice failed to develop arthritis unless they were reconstituted with spleen cells from normal donors within 25 days of irradiation. Second, mice irradiated up to 50 days after pristane injection, but not later, did not develop arthritis. Evidence for the involvement of an immune response to heat-shock protein (hsp) comes from the finding that mice injected with mycobacterial 65-kDa hsp prior to pristane challenge had a reduced incidence of arthritis in contrast to animals pre-immunized with the E. coli hsp equivalent GroEL or with bovine serum albumin. Other experiments revealed that T cells from mice with gross morphologically defined arthritis proliferated strongly to hsp65 and to normal joint antigens, whereas T cells from animals treated with pristane which did not develop arthritis gave much smaller responses. Mice which developed arthritis also had elevated levels of anti-hsp65 IgG in comparison with non-arthritic animals. These findings strongly suggest that autoimmune reactions to an antigen which cross-reacts with hsp65 are generated in pristane-induced arthritis. It is considered that the autoimmune response is directed to a synovial antigen and that pre-immunization with hsp65 protects the animals from the development of pristane-induced arthritis by altering the specificity or quality of the immune response to this antigen.

Animals↗
PubMed1990

Temporal association between Der pI exposure, immediate hypersensitivity and clinical severity of eczema.

Uncontrolled studies of avoidance of house dust mite (Dermatophagoides pteronyssinus) by atopic subjects have reported clinical improvement in the severity of eczema. The aim of the present study was to examine the temporal relationship between environmental exposure to the major mite allergen (Der pI) and clinical disease severity in children with chronic atopic eczema. Twelve children were identified as being house dust mite-sensitive on the basis of skin prick test and RAST to Der pI. They were examined on two occasions with a median interval of 63 days. Clinical severity of eczema improved in nine children and deteriorated in two children during this period. Der pI concentration in dust from mattresses changed significantly in only three subjects and there was no correlation between changes in clinical severity and changes in environmental Der pI exposure. Change in RAST against Der pI did correlate positively with change in Der pI exposure (rho = 0.56, P less than 0.05) but these changes were not associated significantly with changes in eczema severity or skin test response to Der pI. It is concluded that the observed changes in clinical severity were unlikely to be due to immediate hypersensitivity responses to natural variations in Der pI concentrations in the personal environments of these subjects.

Adolescent↗
PubMed1990

The need for an Alzheimer's disease patient registry in South Carolina.

There has been considerable interest in establishing a statewide registry of Alzheimer's disease patients. The need for such a registry, how it could be effectively organized, and the potential benefits from such a registry are discussed. The current status of the South Carolina Registry for Dementing Illnesses is reported.

Aged↗