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Biomedical subjects

J R Gibson

Publications and source records attributed to J R Gibson.

At least 55 records · Page 3Linked to original sources

ras p21 and other Gn proteins are detected in mammalian cell lines by [gamma-35S]GTP gamma S binding.

The presence of guanine nucleotide binding proteins in mouse and human cell lines was investigated using [gamma-35S]GTP gamma S and [gamma-32P]GTP. Cell lysate polypeptides were separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis and transferred to nitrocellulose. Incubation of the nitrocellulose blots with [gamma-35S]GTP gamma S identified 9 distinct GTP-binding polypeptides in all lysates. One of these is the ras oncogene product, p21, as demonstrated by subsequent immunochemical staining of the nitrocellulose blots. We have shown that this procedure provides a sensitive method for detection of p21 in culture cell lines.

Animals↗

Acrivastine: a review of its dermatopharmacology and clinical activity.

The general human and skin pharmacology of acrivastine, its clinical utility and some important concepts of the use of H1-antihistamines in dermatology are discussed. The drug has potent H1-antihistamic activity yet a low sedative profile as compared with first generation agents. Acrivastine is rapidly absorbed with peak inhibition of flare areas occurring at 90 min and peak activity against weals at 120 min after drug administration. No accumulation of the drug following multiple dosing has been demonstrated. Due to these effects the drug has a high level of patient acceptability and a high level of useful activity in a range of histamine-mediated dermatoses.

Histamine H1 Antagonists↗

A comparison of acrivastine versus terfenadine and placebo in the treatment of chronic idiopathic urticaria.

Patients (n = 56) with a diagnosis of chronic idiopathic urticaria were assessed in a fully randomized, double-blind, crossover study to investigate the efficacy of acrivastine at two doses (8 and 4 mg) versus 60 mg terfenadine and placebo administered three times daily. All three active preparations were found to be effective, and significantly better than placebo, in controlling the signs and symptoms of urticaria. No significant differences were found between the active preparations, although in some cases efficacy trends favoured 8 mg acrivastine and terfenadine over 4 mg acrivastine. No significant differences were noted between the active treatments and placebo with regard to reports of drowsiness.

Adult↗

A comparison of acrivastine versus hydroxyzine and placebo in the treatment of chronic idiopathic urticaria.

A total of 21 patients with a diagnosis of chronic idiopathic urticaria were assessed in a fully randomized, double-blind, crossover study to investigate the efficacy of 8 mg acrivastine versus 20 mg hydroxyzine and placebo administered three times daily. Both acrivastine and hydroxyzine were found to be effective, and significantly better than placebo, in controlling signs and symptoms of urticaria. No significant differences were found between the active preparations. Hydroxyzine was associated with significantly more reports of drowsiness than was placebo.

Adult↗

A comparison of acrivastine versus clemastine and placebo in the treatment of patients with chronic idiopathic urticaria.

Twenty patients of mean age 41.3 years, with a diagnosis of chronic idiopathic urticaria were assessed in a fully randomized, double-blind, crossover study to investigate the efficacy of acrivastine at two doses (8 mg and 4 mg) versus 1 mg clemastine and placebo, given three times per day. All active preparations were found to be effective, and significantly better than placebo, in controlling the signs and symptoms of urticaria. There was a higher incidence of sedation with clemastine than with either acrivastine or placebo, although this difference did not achieve statistical significance in this small study.

Adult↗

A comparison of acrivastine versus chlorpheniramine in the treatment of chronic idiopathic urticaria.

A total of 20 patients with a diagnosis of chronic idiopathic urticaria were entered into a fully randomized, double-blind, crossover study to investigate the efficacy of 8 mg acrivastine versus 4 mg chlorpheniramine three times daily. Data from 16 patients were available for analysis. Both acrivastine and chlorpheniramine were found to be effective in relieving the signs and symptoms of urticaria. There were no significant differences between the two treatments, although efficacy trends were generally in favour of acrivastine over chlorpheniramine throughout the study.

Adult↗

Acrivastine--an evaluation of initial and peak activity in human skin.

Twenty-four healthy volunteers were entered into a double-blind, crossover study conducted to establish the time of onset of action and the time to peak activity of acrivastine in suppressing the weal and flare responses to intradermally injected histamine. Volunteers received single doses of 8 mg acrivastine and placebo according to a fully randomized, balanced treatment plan. Acrivastine significantly (P less than 0.001) reduced both the weal and flare responses induced by histamine challenge 30 min after oral dosing, as compared with placebo. Peak inhibition of the flare response was seen at 90 min, and maximal suppression of the weal response occurred at 120 min after administration of acrivastine.

Clinical Trials as Topic↗

Acrivastine versus terfenadine in the treatment of symptomatic dermographism--a double-blind, placebo-controlled study.

Twelve patients with symptomatic dermographism were entered into a double-blind, crossover study. Patients received 8 mg acrivastine three times daily, 60 mg terfenadine three times daily or placebo, according to a fully randomized balanced treatment plan. Subjective clinical assessments were performed and the response to experimentally induced dermographism was assessed. Both active treatments were well tolerated and were shown to be significantly more effective than placebo in the treatment of symptomatic dermographism and in reducing the signs and symptoms of wealing induced by a dermographometer.

Adult↗

The effect of trimethoprim-polymyxin B sulphate ophthalmic ointment and chloramphenicol ophthalmic ointment on the bacterial flora of the eye when administered to the operated and unoperated eyes of patients undergoing cataract surgery.

Both eyes of patients undergoing cataract surgery were treated with an ointment preparation containing either trimethoprim 5 mg/g and polymyxin B sulphate 10,000 units/g, or chloramphenicol 1%. The antibiotic preparations were administered four times daily on the day prior to surgery, once in the morning prior to surgery and twice daily for fourteen days post-operatively. Cultures from conjunctivae and lid margins were taken prior to treatment, pre-operatively and post-operatively on selected days including the fourteenth post-operative day. The effect of the antibiotics on conjunctival and lid margin flora was determined by enumerating patients with positive cultures prior to treatment which were eradicated following treatment and patients with organisms which were cultured de novo in spite of antibiotic treatment. There was no significant change in the number of patients with organisms isolated from conjunctivae and lid margins (p greater than 0.1 in each case, Sign test) over the sixteen day study period with either treatment. Additionally, when the effect of the two preparations on the number of patients with organisms obtained from conjunctivae and lid margins was compared, there was no significant difference between them (p greater than 0.1 conjunctival cultures, p greater than 0.1 lid margin cultures, Fisher's Exact probability test).

Bacteria↗

Comparison of the new antihistamine acrivastine (BW 825C) versus cyproheptadine in the treatment of idiopathic cold urticaria.

A double-blind, crossover trial with a new triprolidine derivative, acrivastine (BW 825C; 8 mg 3 times daily), cyproheptadine (4 mg 3 times daily) and placebo was carried out in 18 patients suffering from idiopathic cold urticaria. Acrivastine and cyproheptadine significantly (p less than 0.01) reduced weal areas following ice cube challenge when compared to placebo. Acrivastine was found to be significantly more effective (p less than 0.01) than cyproheptadine in reducing weal areas. Furthermore, cyproheptadine caused significantly more drowsiness than acrivastine (p = 0.021) or placebo (p = 0.013), which did not differ from each other. This study shows that acrivastine is an effective agent in the treatment of cold urticaria and suggests that acrivastine in the dose used lacks adverse effects, such as drowsiness, traditionally associated with antihistamine therapy.

Adult↗

Trimethoprim-polymyxin B sulphate ophthalmic ointment in the treatment of bacterial conjunctivitis: a double-blind study versus chloramphenicol ophthalmic ointment.

Forty-two patients with a clinical diagnosis of bacterial conjunctivitis were enrolled in a randomized, double-blind trial. Patients were treated with either trimethoprim-polymyxin B sulphate or chloramphenicol ophthalmic ointments 4-times a day for 7 days. Analysis of clinical evaluation data showed that both treatments were effective and well tolerated, and that there were no statistically significant differences between them with regard to eradication of organisms or clinical improvement.

Adolescent↗

Acrivastine versus hydroxyzine in the treatment of cholinergic urticaria. A placebo-controlled study.

Ten patients with cholinergic urticaria (CU) were entered into a double-blind, placebo-controlled, cross-over study. They were scheduled to receive acrivastine 8 mg t.d.s., hydroxyzine hydrochloride 20 mg t.d.s. and placebo according to a fully randomized, balanced treatment plan. Subjective clinical assessments and objective measurements following exercise challenge were performed during the study period. Both acrivastine and hydroxyzine were shown to be effective and well tolerated in the treatment of cholinergic urticaria. In addition, a trend was demonstrated for both active agents to improve peak expiratory flow rate (PEFR) following exercise, when compared with placebo, and this trend reached statistical significance in the case of acrivastine (p less than 0.05).

Adult↗