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Biomedical subjects

D G Sheahan

Publications and source records attributed to D G Sheahan.

50 records · Page 3Linked to original sources
PubMed1975

Medical and surgical management of reflux esophagitis. A 38-month report of a prospective clinical trial.

We compared the surgical and medical managements of reflux esophagitis in a prospective managements of reflux esophagitis in a prospective clinical trial. Patients wissigned to surgical (15 patients) and medical (16 patients) groups. A non-randomized medical group (20 patients) was also studied. Seventy three per cent of the surgical and 19 per cent of the medical group had an excellent to good response. A fair to poor response was observed in 81 per cent of medical and 27 per cent of surgical patients. Symptomatic improvement was accompanied by normal findings on acid infusion test and esophagoscopy. The histologic appearance of the squamous mucosa, however, remained abnormal in all but one patient. In patients who did well after operation there was improvement in resting lower-esophageal-sphincter pressures and absence of gastroesophageal reflux. The relative increases in pphincter pressure to graded increases in gastric pressure, however, remained abnormal in all but one patient.

Biopsy↗
PubMed1975

Variable expression of Marfan syndrome in monozygotic twins.

A pair of monzygotic twins with the Marfan syndrome with variable expression is presented. One of the twins, in addition to more severe musculoskeletal and ocular manifestations, had coarctation of the aorta as the cardiovascular manifestation of this symdrome. Analysis of red cell antigens, serum proteins and dermatoglyphic examination suggests a high probability of monozygosity. Accordingly, the variation in expression of this autosomal dominant disorder between the twins is most likely due to the modifying influences of environmental factors. Also noteworthy is the fact that the resected coarctation tissue demonstrated the histopathologic changes characteristic of cystic medial necrosis, and thus served as an additional piece of evidence supporting the diagnosis of the Marfan syndrome. This was of particular importance in view of the absence of any family history of this syndrome and the absence of ectopia lentis or the more typical cardiovascular manifestations in either twin.

Adolescent↗
PubMed1972

Virulence of Shigella flexneri hybrids expressing Escherichia coli somatic antigens.

The genes controlling either Escherichia coli somatic antigen 8 or 25 were conjugally transferred to virulent Shigella flexneri 2a recipients to determine whether the aquisition of these antigens would affect the virulence of the resulting hybrid. A high proportion of such hybrids were found to be rough and hence were avirulent. Some smooth S. flexneri hybrids which replaced their native group antigens with E. coli factor 25 were still virulent in the animal models employed. All S. flexneri O-8 hybrids were uniformly avirulent. Our finding, that S. flexneri hybrids with the chemically divergent E. coli O-8 repeat unit are avirulent whereas some hybrids with the chemically related O-25 repeat unit retain virulence, suggests that the chemical composition and structure of the O side chain of somatic antigens may represent one determining factor for bacterial penetration of mucosal epithelial cells, the primary step in the pathogenesis of bacillary dysentery.

Animals↗