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Biomedical subjects

Richard A Johnson

Publications and source records attributed to Richard A Johnson.

5 recordsLinked to original sources
PubMed2002

Granulomatous and suppurative dermatitis at interferon alfa injection sites: report of 2 cases.

It has previously been reported that interferon alfa injection sites may develop pyoderma gangrenosum, interface dermatitis, vasculitis, or, more commonly, ulcers characterized by intravascular thrombi and a mixed inflammatory cell infiltrate. We describe 2 patients in whom granulomatous and suppurative dermatitis developed at interferon alfa injection sites. These cases extend the spectrum of interferon alfa injection site reactions. The histologic and clinical similarities of these cases with pyoderma gangrenosum and cutaneous Crohn's disease are explored.

Granuloma↗
PubMed2002

Web-based orthodontic instruction and assessment.

Orthodontic records-study models, panoramic and cephalometric radiographs, and the patient's facial and intraoral photographs-are used to collect data to establish a diagnosis and to develop problem-solution lists. These records, however, can be damaged or lost when dispensed to students and need to be stored and maintained every year. An orthodontic diagnosis web site, therefore, has been set up using digital records to provide students with an accessible source of complete, good-quality study materials. The web site is also used for clinical examination in orthodontic courses. The effectiveness of the web-based digital records in providing relevant information to students in comparison to the traditional records was evaluated by a randomized controlled trial involving ninety-nine second-year dental students. One group (fifty students) studied two cases from the web site; the other group (forty-nine students) studied the same two cases from traditional orthodontic records. Effectiveness was assessed by comparing test scores and the time spent on the tests by t-statistics. There were no significant differences between means for the two study groups in test performance or time. Attitudes of students toward the web site, assessed from post-test questionnaires, were positive. It was concluded that web-based digital orthodontic records were as effective in teaching clinical orthodontic diagnosis as were conventional records.

Attitude↗