Biomedical subjects

R C Cornell

Publications and source records attributed to R C Cornell.

6 recordsLinked to original sources

PubMed1992

Clinical trials of topical corticosteroids in psoriasis: correlations with the vasoconstrictor assay.

It would be desirable to develop an alternative system to clinical studies to evaluate the potency of generic topical corticosteroids and of new formulations of existing innovator corticosteroids. The vasoconstrictor assay is a reliable method for testing potency; however, its results do not always agree with clinical studies. Psoriasis offers an ideal clinical model to evaluate corticoid potency because the ability to perform within-patient comparisons of the treatment of bilateral lesions permits meaningful comparisons with a relatively small sample size. The results of bilateral comparisons in psoriasis agreed with those of the vasoconstrictor assay in 20 of 23 comparisons of active agents and in numerous comparisons of active corticosteroids with a placebo. Eczematous dermatoses do not lend themselves well to bilateral paired comparison studies and therefore require parallel treatment studies with relatively large sample sizes to produce statistically significant comparisons.

Administration, Topical↗

PubMed1979

Laboratory induction and clinical occurrence of combined clindamycin and erythromycin resistance in Corynebacterium acnes.

Corynebacterium acnes strains cross-resistant to clindamycin and erythromycin were observed following long-term selection or mutagenic treatment in the laboratory. Similar strains were found among clinical isolates from patients using clindamycin or erythromycin topically in the treatment of acne vulgaris. Clindamycin resistance was never observed in the absence of resistance to macrolides or other lincosaminides. It is suggested that this resistance may result from an alteration of the 50S ribosomal subunit.

Clindamycin↗

PubMed1979

Plasma complement and histamine changes in atopic dermatitis.

Fifteen patients with atopic dermatitis were investigated to evaluate the total of complement and histamine. In five patients total serum complement haemolytic activity (CH50) was significantly decreased as was the haemolytic activity of complement components C2 (C2H50) and C3 (C3H50). By counter immunoelectrophoresis split products of C3 were detected. There was no evidence for alternative pathway activation or the presence of an activator of the alternative pathway. In three patients plasma histamine concentrations were elevated. The intensity of the complement and histamine changes observed seemed to be correlated to the severity of the disease.

Adolescent↗

PubMed1978

Complement and immunoglobulin deposits in the skin of patients with atopic dermatitis.

The immunofluorescent patterns of uninvolved and involved skin biopsies from eight patients with atopic dermatitis were studied, using direct immunofluorescence techniques to identify deposits of the immunoglobulins G, A and M as well as the complement factors C1q, C3, C4, C5, factor B and properdin. Immunoglobulin deposits (mainly IgG) were found in five patients, complement deposits in three patients in the basement membrane zone. In three patients the immunofluorescence was positive for C3, in two patients for C1q, C4 and C5. Regarding the factors of the alternative pathway of the complement system, two patients showed deposits of properdin, one of factor B. The changes were not confined to the eczematous lesions, but were found in uninvolved skin too. The most prominent changes were observed in patients with severe disease.

Adolescent↗

PubMed1978

New cream vehicle for flurandrenolide.

New methods are now available to help select vehicles for topical corticosteroids. In the development of a new cream vehicle for flurandrenolide, the goal was a cream base with optimal solubility for release of the drug, minimal irritation potential, and no sensitizing preservatives. Vasoconstriction tests make selection much more scientific, and a newer method for such testing is described in detail. Irritation testing then helped determine the vehicle concentration that was least irritating. Final studies included double-blind comparisons with the previous formulation in the treatment of psoriatic patients.

Biological Availability↗

PubMed1976

Anemia of azaribine in the treatment of psoriasis.

Azaribine is an effective agent in the treatment of psoriasis. In this investigation the extent of clinical dermatologic remission appeared to correlate with the degree of metabolic block induced by 6-azauridylic acid, as quantitated by the urinary excretion of orotic acid and orotidine, and the development of anemia. Following azaribine therapy there was a coordinate rise of the specific activities of erythrocyte orotate phosphoribosyltransferase and orotidine-5'-monophosphate decarboxylase. There was no correlation between the pretreatment activity of these enzymes and the clinical response to azaribine. The anemia of azaribine therapy was mile and of a megaloblastic type. Uridine effectively corrected the azaribine-induced anemia, but led to exacerbation of the patients' psoriasis. Following uridine therapy there was a reduction in the urinary excretion of orotic acid and orotidine, presumable reflecting end-product inhibition or repression of the first steps of a repeated pyrimidine biosynthesis.

Adult↗