Biomedical subjects

R E Lyons

Publications and source records attributed to R E Lyons.

4 recordsLinked to original sources

PubMed1978

Comparative effectiveness of benzoyl peroxide and tretinoin in acne vulgaris.

A controlled, randomized clinical study comparing different commercially available benzoly peroxide gels and tretinoin cream was undertaken by four investigators using similar protocols and case report forms. Results were based on lesion-count reduction over an 8-week period. No significant difference in reduction of total acne lesions was detected between the benzoyl peroxide gels and tretinoin cream. However, benzoyl peroxide was significantly better (P less than .02) in reduction of papules and as good as tretinoin in reduction of comedones. Results of this study suggest that excessive drying and peeling are not essential in the reduction of acne lesions.

Acne Vulgaris↗

PubMed1978

Ultrastructural basis for the assay of topical acne treatments. Transmission and scanning electron microscopy of untreated comedones.

After two decades of using systemic antibiotics as a main treatment for acne, emphasis is again being placed on topical agents. Thus, it is highly desirable to have a procedure whereby the activity of the various compounds can be evaluated by direct visualization. Scanning electron microscopy combined with transmission electron microscopy provide the tools for such in assay. This study describes the ultrastructure of untreated comedones and provides the baseline or control data necessary for testing topical treatments. Comedones obtained by punch biopsies or comedo extractors were processed for electron microscopy and studied with an ETEC Autoscan Scanning Electron Microscope and with Philips EM 300 and EM 301 Transmission Electron Microscopes. Microorganisms, keratinized cells, sebum, and hairs interact with each other to form the comedonal mass. Corynebacterium acnes and Pityrosporum ovale proliferate abundantly in close association with sebum and penetrate the keratinized cells. Fine structural details of bacteria and yeasts as well as features of host-microbial relationship have been elucidated.

Acne Vulgaris↗

PubMed1977

A simplified technique for casting anatomical models.

For anyone desiring to cast anatomical models, a simplified technique for external casting has been developed using dental impression materials readily available in dental supply houses. These impressions yield life-like permanent models retaining topographical features of normal as well as pathological skin and nails.

Dental Impression Materials↗

PubMedDate not supplied

Response of multiple seizure types to corpus callosum section.

Twenty-four patients (16 men, 8 women) underwent corpus callosum section specifically for improvement of control of atonic or tonic seizures that resulted in falls and injuries. All patients suffered from multiple seizure types, including complex partial (CP) and tonic-clonic (TC) seizures, in addition to the tonic or atonic episodes. Preoperative seizure frequency was quantified for all types for 1 year immediately before surgery and for the most recent year since the procedure; average monthly counts were obtained for each seizure type. The period of follow-up since surgery averaged 43 months (range, 23-79 months). Statistically significant improvements were documented, not only for the atonic/tonic seizures (p less than 0.0001) for all patients, but also for TC seizures (17 patients; p less than 0.001) and CP seizures (20 patients; p less than 0.02). Six patients experienced an exacerbation of CP seizures postoperatively, and three developed new simple partial (SP) seizures. In all of the CP group and all three of the SP group, ictal video and EEG features suggested that the new seizures were an aborted expression of the previously generalized seizures. From these data, we conclude that callosotomy is an effective treatment for tonic, atonic, and TC seizures intractable to anticonvulsant medications. Three patients became seizure free. The procedure may also be useful for certain specific subgroups of CP epilepsy, but further studies are required before expanding callosotomy to intractable CP seizures not amenable to focal resection.

Accidental Falls↗