Biomedical subjects

S McCall

Publications and source records attributed to S McCall.

22 records · Page 2Linked to original sources

PubMed1992

Immunogenetics of collagen-induced arthritis in rats. Both MHC and non-MHC gene products determine the epitope specificity of immune response to bovine and chick type II collagens.

Seven inbred, RT1-congenic rat strains were immunized with native bovine (BII), porcine (PII), or chick (CII) type II collagen and observed for onset, incidence, and severity of arthritis. Clinical results were compared with IgG reactive with native rat type II collagen (RII) and the purified, renatured cyanogen-bromide peptides of BII, CII, or RII. Immunodominant responses to CB11, CB9,7, and CB12 of RII were identified. Secondary responses to CB8 and CB10 also occurred. Reproducible patterns of peptide reactivity were defined in each strain and reflected both RT1 and non-RT1 genotypes plus the species of immunizing collagen. BN non-RT1 gene products moderated clinical arthritis but increased the levels of reactivity to CB11 in three strains carrying RT1l,n,av1 haplotypes. WF (RT1u) rats were susceptible to collagen-induced arthritis (CIA) and developed very high levels of autoantibodies with dominant responses to rat CB11 after CII injections and to rat CB11 and CB9,7 after BII injections. DA (RT1av1) rats developed the most severe arthritis but had only moderate (total) levels of anti-RII IgG: a broad response to CB11, CB10, and CB9,7 after CII injections but predominantly to CB12 and CB9,7 after BII injections. Three RT1n strains--DA.1N(BN), WF.1N(MAXX), and BN--were resistant to BII-induced CIA but developed mild arthritis after immunization with CII. After BII: BN IgG reacted with CB9-7, CB11, and CB12; DA.1N and WF.1N IgG reacted with CB9,7 and CB12. After CII: BN IgG reacted broadly with CB11, CB9-7, CB12, and CB8; WF.1N IgG reacted to CB9-7, CB11, CB8, and CB12; DA.1N IgG reacted with CB8, CB11, and CB9-7. Thus, selective induction of CIA in BN, WF.1N, and DA.1N rats by CII correlated with serum IgG reactivity to rat CB11, but overall strain results identified no single cyanogen-bromide peptide as expressing the sole "arthritogenic" epitope in CIA.

Animals↗

PubMed1991

Pediatric ABR screening: pass-fail rates in awake versus asleep neonates.

The auditory brainstem response (ABR) is commonly used as a neonatal hearing screening tool. The degree to which myogenic and/or movement artifact can confound the ABR in neonates, and the effect this has on screening pass-fail rates, although widely recognized, have not been reported. This study addressed these aspects in a clinical setting. Fifty-two high-risk neonates were screened in various states of activity (asleep, awake-calm, awake-active). Pass-fail rates between asleep and awake babies were significantly different (p less than 0.5), with the awake group displaying a much higher failure rate. There was no significant difference between the awake-calm and awake-active groups. Results indicate that activity state should be noted and considered along with the other factors that are generally blamed for false-positive results in neonatal ABR screenings.

Activity Cycles↗

PubMed1990

Effects of indomethacin, cyclosporin, cyclophosphamide, and placebo on collagen-induced arthritis of mice.

The long term effects of indomethacin, cyclosporin, cyclophosphamide, and placebo on collagen-induced arthritis in mice were tested under two different treatment protocols. A prophylactic experiment examined the effects of the daily drug administration for 180 days beginning one day before the first collagen injection. Under this dosage schedule, cyclophosphamide and cyclosporin decreased the severity of arthritis, while indomethacin did not. A therapeutic protocol examined the effects of these same drugs when daily administration was delayed until the animals had active disease at 78 days after the first collagen injection. Under this protocol, all three drugs reduced the progression of disease. In both protocols, the most significant suppression of arthritis was seen in animals receiving cyclophosphamide which was associated with a decrease in anti-collagen antibody levels. Collagen-induced arthritis in mice should be further investigated as a model to study the long term effects of "slow-acting" anti-rheumatic drugs.

Animals↗

PubMed1990

Inhibition of the passive transfer of adjuvant induced arthritis by gold sodium thiomalate.

The effect of gold on the passive transfer of adjuvant induced arthritis was studied to determine if gold acted in the donor and/or recipient arms of this model. Joint scores were markedly decreased in rats receiving spleen cells from donor animals treated with gold (p less than 0.01) suggesting that gold injections alters the development and/or function of the spleen cells from these animals which transfer adjuvant induced arthritis. Gold treatment of recipient animals had little effect on subsequent arthritis.

Animals↗