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Biomedical subjects

S Shuster

Publications and source records attributed to S Shuster.

At least 127 records · Page 7Linked to original sources
PubMed1985

Minimal effect of complete H1 receptor blockade on urticaria pigmentosa.

The effect of complete H1 receptor blockade on urticaria pigmentosa was studied in 6 patients. Astemizole 10 mg tds was given for 6 weeks to achieve complete H1 receptor blockade and the response measured by change in force-weal response measurements using two different forces on a dermographic stylus and measuring response as weal diameter. Weal and flare reactions to 8 micrograms histamine were completely abolished by the astemizole but dermographic weal-force responses were reduced only by 12-15% indicating that histamine acting at the H1 receptor plays only a small part in the wealing of urticaria pigmentosa.

Adult↗
PubMed1985

Susceptibility and amplification of sensitivity in contact dermatitis.

We have examined the hypothesis that people who develop contact allergies to environmental substances do so because they have heightened susceptibility. Analysis of data from 2200 consecutive patients tested with the 20 commonest antigens in a patch-test clinic showed that more people developed multiple contact allergies than would be predicted from the frequency of single allergies; the excess was too great to be explained by chance and increased with number and rarity of the combinations of sensitizers. The possibility that this was due to enhanced individual susceptibility to sensitization rather than concomitant exposure to several sensitizers was confirmed by showing that patients with multiple allergies are more readily sensitized experimentally, and to a greater degree than normal, by dinitrochlorobenzene (DNCB), an unrelated antigen. The defect involves induction rather than expression of sensitivity. Amplification of the response to DNCB is proportional to susceptibility (calculated from the ratio of observed prevalence of multiple allergies to that predicted from the prevalence of single allergies) throughout the range from normal subjects, through those with a single sensitivity, to those with rare, multiple allergies. Therefore, we conclude that individual susceptibility is an important factor in the development of contact dermatitis, and occurs by a non-antigen-specific amplification of immune sensitization.

Adult↗
PubMed1984

Effects of isotretinoin on serum lipids and lipoproteins, liver and thyroid function.

Seven patients with severe rosacea were treated with 1 mg/kg per day isotretinoin for 12 wk. There were significant increases in serum triglyceride (p less than 0.001) and cholesterol (p less than 0.001). Triglyceride associated with very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL) increased (p less than 0.01), cholesterol in VLDL and LDL increased (p less than 0.01), and levels of HDL cholesterol decreased (p less than 0.01). There were changes in indices of liver function, with increased levels of gamma-glutamyltransferase (GGT) (p less than 0.01), alkaline phosphatase (ALP) (p less than 0.01) and aspartate aminotransferase (AST) (p less than 0.01), and decreased bilirubin levels (p less than 0.05). Although levels of thyroxine and triiodothyronine were lower after treatment (p less than 0.05), there were no changes in basal levels of thyroid-stimulating hormone (TSH), luteinizing hormone (LH) or follicle-stimulating hormone (FSH), and responses to thyrotrophin releasing hormone (TRH) and luteinizing hormone releasing hormone (LHRH) were unchanged. These changes may partially be explained by induction of hepatic microsomal enzymes by isotretinoin.

Adult↗
PubMed1984

Inhibition of dithranol inflammation by free-radical scavengers.

Dithranol (anthralin) inflammation of forearm skin was completely inhibited by various scavengers of free radicals of the oxygen species. It is concluded that dithranol inflammation is initiated by formation of free radicals; these may act through lipid peroxidation and production of inflammatory endoperoxides or by a more direct mechanism.

Administration, Topical↗
PubMed1984

Induction of drug metabolising enzymes in the skin by topical steroids.

The effects of the topical application of glucocorticoid steroid creams used in clinical practice, on the activity of drug metabolising enzymes in the skin of adult hairless mice has been investigated. Treatment with hydrocortisone and fluandrenolone had no effect on the activity of ethoxycoumarin O'dealkylase (EOD) in the skin whereas all other fluorinated synthetic glucocorticoids tested, significantly induced cutaneous EOD activity. Fluincinolone acetonide, Fluincinonide , and Betamethasone Valertate increased enzyme activity 2-3-fold, and clobetasol propionate induced enzyme activity 6-fold. The ability of each steroid preparation to induce enzyme activity was related to its clinical potency, and induction of enzyme activity by clobetasol propionate was maximal at 0.05%, the concentration used in clinical practice. The effects of clobetasol propionate on cutaneous ethoxycoumarin and ethoxyresorufin dealkylase activities were different from those produced by 3 methycholanthrene , indicating that glucocorticoids may represent a class of inducing agents with different properties from the polycyclic hydrocarbons.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1984

Characterization and quantification of epidermal and dermal glucocorticoid receptors in the rat.

The interaction between [3H]triamcinolone acetonide and cytosol proteins was studied in separated epidermis and dermis of neonatal rats. Both tissues possessed a binding site with a high affinity (dissociation constant = 0.2 nM) and a low capacity (150-220 fmol/mg protein) for triamcinolone acetonide. The binding site in each tissue cytosol was inactivated by heating at 37 degrees C or by incubating with either trypsin, Triton X-100 or NaCl. The second-order rate constant of association was 1.99 X 10(6)M-1min-1 for the epidermal, and 1.65 X 10(6)M-1min-1 for the dermal receptor binding site. Quantitatively there was a difference between the two tissues with 82% of the receptor being found in the dermis and 18% in the epidermis.

Animals↗
PubMed1984

Reduction of antipyrine clearance in psoriasis.

Antipyrine clearance was determined in 41 psoriatics and age-sex matched controls, using sequential measurements of salivary concentration. Antipyrine clearance and elimination rate constant were less in psoriatics (P less than 0.05) and apparent volumes of distribution were similar. These differences were greater between female psoriatics and controls (P less than 0.025; P less than 0.05) and the differences between male psoriatics and controls were not significant. Correlation of simultaneous measurements of saliva and plasma antipyrine concentration in six psoriatics and age-sex matched controls showed no differences between the two groups. We conclude that antipyrine clearance is reduced in psoriasis but the underlying mechanism is unclear.

Adolescent↗
PubMed1984

Human skin aryl hydrocarbon hydroxylase.

Aryl hydrocarbon hydroxylase (AHH) activity has been measured in full-thickness biopsies of human skin from patients with and without psoriasis. Basal levels of enzyme activity varied over a fivefold range and were not related to age, sex or clinical condition. Induction of AHH activity by the application of coal tar resulted in a two- to fivefold increase in activity above basal levels, which was not related to the presence or absence of psoriasis. Separation of human skin into dermis and epidermis showed that human skin AHH activity is predominantly dermal.

Adolescent↗
PubMed1984

Effect of coal tar on cutaneous aryl hydrocarbon hydroxylase induction and anthralin irritancy.

The inflammatory dose-response to topical anthralin and whole skin aryl hydrocarbon hydroxylase (AHH) activity were measured before and 24 h after application of a coal tar solution to the uninvolved skin of patients with psoriasis. The inflammatory response to anthralin decreased and total AHH activity increased after the tar treatment. A possible explanation is that anthralin or an irritant product is metabolized by AHH activity in the skin. Induction of AHH by coal tar increases its removal and reduces anthralin irritancy.

Adult↗
PubMed1984

Effect of low dose cyproterone acetate on the response of acne to isotretinoin.

Twenty-seven males with severe acne were treated for 12 weeks with 0.05 mg/kg/day isotretinoin (ten patients) or 5 mg daily cyproterone acetate (eight patients) or both drugs together in these doses (nine patients). With isotretinoin, the sebum excretion rate (SER) fell by 45% +/- 9% s.e.m. (P less than 0.0025), lesion count fell by 65% +/- 10% (P less than 0.0005) and median clinical 17% +/- 12% (NS) fall in SER, a 15% +/- 10% (NS) fall in lesion count and the median severity was unchanged. Patients unchanged. Patients treated with both drugs showed a 42% +/- 13% reduction in SER (P less than 0.005), a 68% +/- 11% decrease in lesion count (P less than 0.0005) and a decrease in median severity from 8 to 4 (P less than 0.01) which was no different from the response to isotretinoin alone. Isotretinoin increased serum cholesterol from 4.4 mmol/l +/- 0.3 s.e.m. to 4.7 mmol/l +/- 0.3 s.e.m. (P less than 0.01), serum triglyceride from 0.73 mmol/l +/- 0.07 s.e.m. to 0.96 mmol/l +/- 0.14 s.e.m. (P less than 0.05) and gamma-glutamyltransferase (GGT) from 15.9 i.u./l +/- 2.1 s.e.m. to 19.0 i.u./l +/- 2.4 s.e.m. (P less than 0.01). Comparison of the area under the concentration-time curve for triglyceride and high density lipoprotein (HDL)-cholesterol showed that the changes were smaller when isotretinoin was combined with cyproterone acetate. We conclude that the effect of isotretinoin in acne was not enhanced by the antiandrogen, but the increase in serum triglyceride and decrease in HDL-cholesterol produced by the retinoid were reduced by combination with the antiandrogen.

Acne Vulgaris↗
PubMed1984

The response of seborrhoeic dermatitis to ketoconazole.

A randomized double-blind placebo-controlled cross-over study was made of ketoconazole 200 mg daily in nineteen patients with seborrhoeic dermatitis. All had scalp lesions and sixteen had seborrhoeic dermatitis at other sites. Responses were measured by clinician and patients independently, using a linear analogue scale. Body and scalp lesions and itch regressed considerably and significantly with ketoconazole in all but five patients, three of whom subsequently responded to a higher dose. The patients studied with seborrhoeic dermatitis had been sent by their family doctors in answer to a request for patients with dandruff, and the clinical difference between the two was found to be only of degree. Three patients with dandruff without erythema were studied separately using the same study design: all three responded similarly to those with seborrhoeic eczema. It is concluded that Pityrosporum yeast infection is the immediate cause of seborrhoeic dermatitis and that dandruff is its mildest manifestation.

Adolescent↗