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Biomedical subjects

P J Lynch

Publications and source records attributed to P J Lynch.

At least 19 recordsLinked to original sources
PubMed1992

Porokeratosis palmaris et plantaris disseminata. Report of a case with abnormal DNA ploidy in lesional epidermis.

BACKGROUND: Porokeratosis is believed to be a premalignant condition of the skin. Recent flow cytometric studies showing DNA aneuploidy in the epidermis of some types of porokeratosis support this conclusion. We describe a patient with porokeratosis palmaris et plantaris disseminata in whom abnormal DNA ploidy was found in lesional epidermis with the use of flow cytometry. OBSERVATIONS: DNA flow cytometry of lesional epidermis from the back showed two populations of cells, one with diploid and the other with aneuploid DNA content and DNA index of 1.1 (hyperdiploid). The coefficient of variation of the diploid and aneuploid peaks was 2.1% and 4.1%, respectively. CONCLUSIONS: Porokeratosis palmaris et plantaris disseminata, like other forms of porokeratosis, exhibits abnormal DNA ploidy in lesional epidermis. This finding underscores the premalignant nature of this and other forms of porokeratosis.

Adult↗
PubMed1992

Henoch-Schönlein vasculitis as a manifestation of IgA-associated disease in cirrhosis.

Cirrhosis has been associated with a variety of glomerular lesions that generally include deposits of IgA in the mesangium. However, loss of renal function secondary to IgA deposition in cirrhotics is infrequent. An unusual patient who developed rapidly progressive glomerulonephritis followed by leukocytoclastic vasculitis with IgA deposition on skin biopsy is presented. We postulate that this is an example of Henoch-Schönlein purpura occurring secondary to altered IgA processing in cirrhosis.

Female↗
PubMed1992

Multimedia for clinical education in myocardial perfusion imaging.

Interactive multimedia has many advantages as a presentation medium for diagnostic imaging case studies, particularly for teaching digital imaging techniques such as myocardial perfusion imaging. Multimedia documents may incorporate interactive audiovisual presentations, sophisticated diagnostic images, anatomical illustrations, and text in medical instructional materials. The article describes a multimedia teaching atlas of SPECT and planar myocardial perfusion imaging delivered on Apple Macintosh II microcomputers, and discusses some of the advantages of delivering medical educational materials with interactive multimedia techniques.

Computer-Assisted Instruction↗
PubMed1990

An introduction to interactive hypermedia.

Current computers can create and display documents that incorporate a variety of audiovisual media, and can be organized to allow the user, guided by curiosity and not by a fixed path through the material, to move through the information in non-linear pathways. These hypermedia documents and the concept of hypertext offer significant new possibilities for the creation of educational materials for the biomedical sciences. If the full capabilities of the computer are to be used to enhance the educational experience for learners, computer professionals need to collaborate with publishing and teaching professionals. Biomedical communications professionals can and should play a role in establishing and evaluating hypermedia documents for medical education.

Audiovisual Aids↗
PubMed1989

Hypermedia techniques for diagnostic imaging instruction: videodisk echocardiography encyclopedia.

Because of the visual complexity of medical images and the intensive tutorial experience required to develop image recognition expertise, professional training programs have concentrated on educating limited numbers of experts. Videodisk and CD-ROM (compact disk read only memory) image storage media now make it possible for a microcomputer workstation to provide a learning environment substantially equivalent to that of conventional time-consuming tutorial methods. A demonstration hypermedia program on echocardiography was constructed that provides a user-controlled learning environment with instant access to 54,000 video frames encompassing 1,200 clinical items. The instructional module is controlled by a microcomputer, which provides electronic linkage to relevant graphics, animations, text, categorized data bases, and digitized sound. The system has been successfully used in a residency program as the primary instructional tool for achieving an intermediate level of clinical expertise. Hypermedia offer substantial advantages over conventional books as a clinical reference source.

Computer-Assisted Instruction↗
PubMed1988

Psychiatric, legal, and moral issues of herpes simplex infections.

When patients first realize that they have genital herpes, they are likely to have a series of psychiatric reactions that include (1) denial, (2) a belief that there is a cure, (3) realization that they do have herpes, (4) loneliness, (5) anger toward their sexual partners, (6) fear of sexual deprivation, and (7) development of a poor self-image. One of the best coping mechanisms is to develop a social support system. Despite many concerns about sexual activities, the patient's work performance often goes on as before. By 1985, law suits by patients against those who allegedly gave them herpes had not resulted in awards at the Appeals Court level and one malpractice suit against physicians was not awarded. Genital infections in children must be regarded as potential child abuse by physicians. Morally, it is right for an infected person to disclose the existence of herpes to a potential partner but this is not always done for fear of compromising a relationship in its early phases. Because one's original infection may be asymptomatic, relating the time of acquisition of an infection to an act of infidelity cannot be judged solely on the basis of the time of the herpetic breakout.

Child↗
PubMed1987

Isotretinoin and cutaneous helper T-cell lymphoma (mycosis fungoides).

Retinoids, including isotretinoin, have demonstrated antiproliferative and antineoplastic activity in laboratory and clinical trials. In a phase II trial, 25 patients with extensive mycosis fungoides were evaluated for response to isotretinoin. There was a 44% (11 patients) objective clinical response rate with three clinical complete responses without concomitant evidence of pathologic clearing of the disease. An additional 24% (six patients) showed a minor degree of clinical improvement. The median time to response was two months (range, 0.5 to eight months) and the median response duration was eight months or longer (range, one to 25 months). Chronic toxic reactions consisted primarily of drying of the skin and mucous membranes and resulted in dose reduction in the majority of patients. It is concluded that isotretinoin produces significant clinical benefit to some patients with mycosis fungoides.

Adult↗
PubMed1987

Vulvar dystrophies and intraepithelial neoplasias.

The warmth and moisture present in all intertriginous locations distorts the lesional morphology of many vulvar diseases. Specifically, wetness leads to the development of a nondistinctive, white hyperhydration of any scale that is present, and this, in turn, masks the characteristic features of the underlying pathology. These same factors increase the severity of pruritus and thus lead to scratching and eczematization of what, in other locations, would be more readily recognizable disease. Those diagnostic hallmarks that do remain are emphasized in this article, and those aspects of therapy that are unique to a vulvar location are discussed.

Adult↗
PubMed1987

Laserprinter applications in a medical graphics department.

Our experience with the Apple Macintosh and LaserWriter equipment has convinced us that lasergraphics holds much current and future promise in the creation of line graphics and typography for the biomedical community. Although we continue to use other computer graphics equipment to produce color slides and an occasional pen-plotter graphic, the most rapidly growing segment of our graphics workload is in material well-suited to production on the Macintosh/LaserWriter system. At present our goal is to integrate all of our computer graphics production (color slides, video paint graphics and monochrome print graphics) into a single Macintosh-based system within the next two years. The software and hardware currently available are capable of producing a wide range of science graphics very quickly and inexpensively. The cost-effectiveness, versatility and relatively low initial investment required to install this equipment make it an attractive alternative for cost-recovery departments just entering the field of computer graphics.

Computer Graphics↗
PubMed1986

An ultrastructural morphometric and immunohistochemical analysis of cutaneous lymphomas and benign lymphocytic infiltrates of skin. Useful criteria for diagnosis.

Our combined ultrastructural, immunohistochemical, histologic, and clinical studies over the past five years have allowed us to compile diagnostic criteria useful in the evaluation of cutaneous lymphomas. As a group, mycosis fungoides (MF) patients could be distinguished from those with benign disorders of skin using ultrastructural morphometry (mean form factor and perimeter values), but with some overlap between groups. Another approach, the ultrastructural histogram method, however, clearly separated MF patients from patients with chronic dermatitis. Immunohistochemistry was useful in distinguishing cases of cutaneous peripheral T-cell lymphoma from MF cases on the basis of the occurrence of "novel phenotypes." Neoplastic T-cell infiltrates of skin can usually be distinguished from benign polyclonal T-cell infiltrates by the presence of one T-cell subset to the exclusion of others. Patients with convoluted B-cell lymphomas could also be distinguished from MF patients using ultrastructural morphometric dual parameter analysis. The diagnostic complexity of several cutaneous T-cell lymphoma cases is illustrated. We have emphasized in this study the strength of combining quantitative electron microscopy, immunohistochemistry, and histology in the diagnostic workup of cutaneous lymphomas. This integrative approach may be necessary to assure a definitive diagnosis in difficult cases.

Adult↗
PubMed1985

The immunoarchitecture of cutaneous pseudolymphoma.

The immunoarchitecture of five cutaneous pseudolymphomas was studied by staining serial sections for T- and B-cell and dendritic reticulum cell (DRC) antigens with monoclonal antibodies, and compared with that of reactive lymph nodes and cutaneous lymphoma. In four cases compartmentalization of B and T cells was observed, analogous to findings in reactive lymph nodes. In two of these cases the immunoarchitectural features were strikingly similar to those of reactive lymph nodes. Both had distinct follicles with germinal centers, and in one distinct mantle zone formation was seen. B cells in the follicles were polyclonal, with kappa chain predominance. The germinal centers showed the expected intercellular and/or dendritic pattern of immunoglobulin heavy chain, B2, and DRC-antigen expression. T cells admixed in the germinal centers were overwhelmingly of the T-helper type. The B-cell compartments in the other two cases showed some subtle immunologic evidence of aberrance, but the weight of evidence suggested reactive/aberrant rather than malignant processes. The T-cell compartments in all four cases showed a predominance of T-helper and a minority of T-suppressor/cytotoxic cells. All contrasted with the lymphomas, which showed B-cell monoclonality, markedly deranged T-subset proportions, or novel T-cell phenotypes. Although the main focus of this study was cases involving substantial populations of both B and T cells, preliminary observations were made in one case in which a predominance of T cells and prominent epidermotropism simulated mycosis fungoides. Quantitative ultrastructural analysis in this case suggested a reactive T-cell process. Leu-6-positive Langerhans cells were increased in the epidermis and dermis in all five cases, and in the dermis they were found almost exclusively in T-cell compartments. It is proposed that this distribution is the anatomic correlate to the known functional role of Langerhans cells in antigen processing/presentation and T-cell activation. In the cutaneous "lymph node equivalent," Langerhans cells are analogous to interdigitating reticulum cells of reactive lymph nodes in distribution and, probably, in function. The DRC found in the germinal centers in two cases were probably antigenically identical and functionally analogous to those in germinal centers of reactive lymph nodes. Immunologic phenotyping of serial cutaneous sections may aid in distinguishing reactive from neoplastic lymphoid lesions. Immunoarchitectural analysis promises to be a powerful tool for the study of lymphoproliferative disease.

Adult↗
PubMed1985

Acrokeratoelastoidosis of Costa in North America. A report of two cases.

This report concerns two unrelated patients with acrokeratoelastoidosis who noted the onset of skin lesions before the age of 20. There was no history of solar damage or evidence of chronic trauma. The case histories and histologic findings of these patients are presented and discussed in relation to a review of the world literature.

Adult↗