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Biomedical subjects

S Shuster

Publications and source records attributed to S Shuster.

At least 19 recordsLinked to original sources
PubMed1992

The route of rapid access of drugs to the distal nail plate.

It has recently been shown that antimycotic drugs have unexpectedly rapid access to distal nail, which we have suggested occurs through the site of continuous ventral nail formation along the nail bed. To exclude the alternative possibility of diffusion through the nail plate, we have measured the effect of topical terbinafine cream in onychomycosis. Sustained outward movement of the fungally affected distal segment was seen in only 2 of 10 measured nails, and there was no change in the mean severity of clinical involvement in 53 nails under study. This excludes significant diffusion of drugs through the nail plate, and we conclude that the route of rapid access is indeed through the nail bed.

Administration, Oral↗
PubMed1992

Skin cancer after renal transplantation: the causal role of azathioprine.

In 167 unselected patients with renal allografts, after a lag of 3.5 years the prevalence of dysplastic keratotic lesions increased linearly by 6.8%/yr and number of lesions also increased. There was no relationship to sun exposure or skin type. Malignancies occurred in 5 patients after 9 years. Viral warts occurred in 42% but prevalence and extent were not related to time after transplantation or keratoses. Comparison with other drugs and diseases suggests malignant keratoses are initiated in two stages by the cytotoxic effect of azathioprine, the role of immunosuppression remaining unproved. Psoriasis and eczema remitted and the prevalence of zoster and fungal disease increased. P. orbiculare (but not P. ovale) infection increased, unlike in other states of immunosuppression, suggesting the organisms are distinct, not transitional, and differently influenced by the different immunodeficient states induced by drugs and disease.

Adolescent↗
PubMed1992

The unexpectedly rapid response of fungal nail infection to short duration therapy.

To test our hypothesis that, by laying down a fungicidal barrier in the growing nail, a short course of antifungal therapy should be effective against onychomycosis, we treated 8 subjects with Trichophyton rubrum nail infection with terbinafine 125 mg b.d. for 14 days. All but one patient showed marked improvement, and 80% of fingernails and 37% of toenails were clinically cured after 6 months. Although this confirmed our prediction, the onset of response measured by outward movement of affected nail and negative cultures from distal nail clippings occurred after as little as 4 weeks. This was too soon for a fungicidal barrier to have grown out and indicates that the drug must have been carried directly into the diseased distal nail, presumably from newly formed ventral nail beneath it. The findings show that 1) short duration therapy, perhaps even a single dose, is possible in fungal nail infections; 2) the ventral nail provides unexpectedly rapid access of drugs to the site of distal disease.

Adult↗
PubMed1992

Topical ketoconazole does not potentiate oral cyclosporin A in allergic contact dermatitis.

Cyclosporin A is an effective drug but its use is limited by its side effects. Since oral ketoconazole inhibits the metabolism of oral cyclosporin, we set out to find out whether topical ketoconazole would enhance the effect in the skin of oral cyclosporin. Five patients with contact allergic dermatitis (CAD) were given a 6-day course of cyclosporin (1 mg/kg/day) and applied 2% ketoconazole cream to an area on one arm and the inert base to the other. Serial dilutions of the relevant allergen were applied to the arms at 3 days for 48 hours, and the responses were measured objectively a day later. There was no significant difference between responses at the two sites, indicating that topical ketoconazole does not enable the dose of oral cyclosporin to be reduced in CAD.

Administration, Cutaneous↗
PubMed1991

Oral cyclosporin inhibits the expression of contact hypersensitivity in man.

The expression of delayed contact hypersensitivity was studied in 6 patients with chronic contact dermatitis treated with cyclosporin A (CsA) 5 mg/Kg/day. Quantitative patch test challenge was used to establish individual dose-response curves and threshold concentration to certain allergens in the European Standard Battery. In all 6 patients, responses were reduced over the whole range of allergen concentrations, and in the 5 in whom the threshold for expression of contact hypersensitivity could be determined, the threshold was raised by CsA therapy. In addition, the clinical manifestations of allergic contact dermatitis underwent complete resolution within 2-3 weeks of CsA therapy. It was concluded that CsA inhibits expression of delayed contact hypersensitivity reactions in human skin.

Administration, Oral↗
PubMed1991

Cyclosporin A in atopic dermatitis: therapeutic response is dissociated from effects on allergic reactions.

Fourteen patients with severe chronic atopic dermatitis were treated with cyclosporin A (CyA, Sandimmun; 5 mg/kg/day) for 7-16 weeks. All showed a marked clinical improvement and half could omit topical corticosteroid treatment during therapy. Adverse effects were minor, but two patients relapsed despite continued treatment. In the others, the disease recurred soon after stopping CyA. Serum IgE levels and prick-test responses were unchanged by CyA. Immediate and late-phase cutaneous responses to intradermal house dust mite antigen (HDM) were significantly increased during treatment; but a delayed response, present at 24 and 48 h, was unaffected. Four of six patients challenged with HDM patch tests to tape-stripped skin during treatment showed eczematous reactions at 48 h. Thus, cyclosporin A has a powerful therapeutic effect in atopic dermatitis but does not reduce allergic responses to inhalant antigens.

Adolescent↗
PubMed1991

Nail is produced by the normal nail bed: a controversy resolved.

Nail thickness and mass (dry weight/unit surface area) of 21 toenails, removed from 19 patients after accidental injury, were measured over the mid point of the lunula, at the nail plate immediately distal to the lunula and at the distal end of the nail bed. Nail thickness increased from 43% of the final thickness over the mid-point of the lunula to 81% at its distal margin, the remaining increase in thickness being formed by the nail bed. The changes in nail mass were comparable. We conclude that ventral nail produced by the nail bed comprises about one-fifth of the terminal nail thickness and mass.

Adolescent↗
PubMed1991

[Cyclosporin A in atopic dermatitis: therapeutic effect and effect on allergic reactions are dissociated from each other].

Fourteen patients with severe chronic atopic dermatitis were treated with cyclosporin A (CyA, Sandimmun; 5 mg/kg/day) for 7-16 weeks. All showed a marked clinical improvement and half could omit topical corticosteroid treatment during therapy. Adverse effects were minor, but two patients relapsed despite continued treatment. In the others, the disease recurred soon after stopping CyA. Serum IgE levels and prick-test responses were unchanged by CyA. Immediate and late-phase cutaneous responses to intradermal house dust mite antigen (HDM) were significantly increased during treatment; but a delayed response, present at 24 and 48 h, was unaffected. Four of six patients challenged with HDM patch tests to tape-stripped skin during treatment showed eczematous reactions at 48 h. Thus, cyclosporin A has a powerful therapeutic effect in atopic dermatitis but does not reduce allergic responses to inhalant antigens.

Adolescent↗
PubMed1991

'Irritants' increase the response to an allergen in allergic contact dermatitis.

We studied the effect of "irritants" on the response to an allergen in 15 patients. Dilutions of allergens were applied in duplicate, and 24 hours later they were removed and sodium lauryl sulfate (11 subjects) or anthralin (dithranol) (four subjects) was applied for a further 24 hours to one set of patches. Control dilutions of irritants alone were applied. Responses were measured objectively at 72 hours. The response to both allergen and irritant was greater than to either alone. Doses of allergen, which did not produce a response when applied alone, produced a response when an irritant was added. Irritants therefore increase the allergic contact dermatitis response and may explain the presence of contact dermatitis in patients with negative patch tests.

Allergens↗
PubMed1990

Reduction of anthralin-induced inflammation by application of amines.

Twenty-two primary, secondary, and tertiary amines were studied to determine whether they could reduce anthralin-induced inflammation. Amine solutions of 0.18 mol/L were applied after anthralin application to normal forearm skin. Inflammation was measured with the use of Harpenden calipers by the increase in skin thickness at 48 hours. Inflammation was reduced by 66% to 95% with the use of nine different amines. There was no overall correlation between the inhibiting effect and either amine basicity or octanol/water partition coefficient. However, within each of the series of primary, secondary, and tertiary alkylamines there appeared to be some correlation between inhibitory effect and alkyl chain size, which may reflect differences in transdermal flux. Some of these amines are used in cosmetics and skin cleansers and could help reduce the inflammation that accompanies anthralin therapy for psoriasis.

Administration, Cutaneous↗
PubMed1990

The effect of triethanolamine application on anthralin-induced inflammation and therapeutic effect in psoriasis.

Twenty patients with chronic plaque psoriasis were treated with short-contact anthralin followed by 10% triethanolamine application to one side of the body and aqueous cream to the other. Anthralin-induced inflammation was inhibited on the triethanolamine-treated side whereas anthralin therapy had to be temporarily stopped in 18 patients on the aqueous cream side because of anthralin-induced inflammation. Therapeutic response was not different in the two sides. This study shows that anthralin-induced inflammation and its therapeutic effect can be dissociated.

Adolescent↗
PubMed1990

The effect of indomethacin on the kinetics of histamine, 48/80 and antigen wealing.

1. The kinetics of weal formation and disappearance following intradermal injection of histamine, compound 48/80 and antigen were measured in indomethacin and inert geltreated human forearm skin. 2. Rates of formation went in descending order for histamine, 48/80 and antigen; rate constants of disappearance for equal sized weals were the same for histamine and 48/80 but were much less for antigen. The corresponding half-lives were 77, 73 and 160 min for histamine, 48/80 and antigen weal disappearance respectively. 3. Cyclo-oxygenase inhibition by topical indomethacin had no effect either on the immediate weal and flare responses or on the rates of formation and disappearance of the weals. 4. These findings together with previous studies using H1-receptor antagonists indicate that 48/80 acts by histamine release but that antigen releases both histamine and an additional material or materials which are not related to cyclo-oxygenase activity. 5. Exacerbation of chronic idiopathic urticaria by cyclo-oxygenase inhibitors is therefore likely to be part of the urticarial disease process.

Adult↗