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Biomedical subjects

R C Gardner

Publications and source records attributed to R C Gardner.

At least 73 records · Page 4Linked to original sources
PubMed1981

Analysis of mini-F plasmid replication by transposition mutagenesis.

Derivatives of a mini-F plasmid in which Tn3 is inserted in F deoxyribonucleic acid were obtained, and the sites of insertion for 40 of the derivatives were mapped. Tn3 was found to insert at many sites within mini-F, but most insertions were within the 43.0- to 43.7-kilobase (kb), 44.2- to 44.7-kb, and 45.9- to 46.3-kb segments. Hence, these segments are unnecessary for mini-F replication. Most of the Tn3 derivatives were similar to their parent miniplasmid with respect to copy number, stability, and incompatibility. Insertions at 45.15 kb and near 46.0 kb caused a moderate disruption of copy number control, and insertion at 47.6 kb resulted in unstable maintenance. Deletion derivatives lacking deoxyribonucleic acid between 40.3 and 44.76 kb and between 45.92 and 49.4 kb were obtained. This observation suggests either that mini-F contains a third origin, in addition to those already reported to be at 42.6 and 44.4 kb, or that the reported position of the secondary origin, 44.4 kb, is incorrect and that this origin is between 44.76 and 45.92 kb.

Base Sequence↗
PubMed1981

Herpetic esophagitis.

Four patients with herpetic esophagitis were examined. In three of them, the presenting symptom was odynophagia. Early in the course of herpetic esophagitis, shallow round and oval ulcers were seen on barium esophagograms. Later, the ulcers filled with fibrinous exudate, forming nodular plaques that projected into the esophageal lumen. Although these findings are diagnostic of esophagitis, they are not specific for a herpes virus infection. The definitive diagnosis must be established by histologic examination, which demonstrates the cytopathic effect of the herpes virus infection within the squamous epithelium.

Adult↗
PubMed1979

Second EcoRI fragment of F capable of self-replication.

The cloning of fragments of F' plasmid deoxyribonucleic acid produced by restriction endonuclease EcoRI has revealed that fragment f7, not previously suspected to have replicative properties, is able to replicate autonomously. The ability of f7 to replicate was observed when it was cloned with fragments coding for resistance to either kanamycin or streptomycin and sulfonamide. Such f7 miniplasmids have been obtained from an F'lac+ and two F'gal+ temperature-sensitive mutant plasmids and from the unmutated F plasmid. Plasmids containing both f5 and f7 fragments were also obtained. Expression of resistance to "female-specific" bacteriophages requires that f5 and f7 be present in the same plasmid since cells containing separate f5 and f7 plasmids are not resistant to bacteriophage phi II. f7 plasmids were less stable than miniplasmids containing f5, particularly at fast growth rates. The bearing of these results on the isolation and behavior of temperature-sensitive F mutants is discussed.

Base Sequence↗
PubMed1978

Serial carcinoembryonic antigen (CEA) blood levels in patients with ulcerative colitis.

Fifty-seven patients with ulcerative colitis were folloued 1-49 months (mean, 18 months) with serial CEA determinations during periods of remission, mild relapses, and severe relapses. Elevated CEA titers correlated with activity and possibly extent of disease: 12% of patients with proctitis, 47% of patients with left-sided colitis, and 60% of patients with transverse or universal colitis had elevated CEA titers during a flare. Moreover, 24% of patients with mild flares and 86% of patients with severe flares had elevated CEA titers. Ninety-two percent of patients with extensive disease and severe flares had elevated CEA titers. Elevated CEA titers were correlated with histologic findings in three patients. Inflammation of mucosa was demonstrated by colonoscopy and confirmed by biopsy in one patient with persistently elevated CEA titers during clinical remission. In two other patients with active disease whose CEA titers fell prior to colectomy, marked denudation of colonic mucosa was noted. In this study, a transiently elevated CEA titer indicated either clinically active ulcerative colitis or active inflammation of colonic mucosa.

Carcinoembryonic Antigen↗
PubMed1976

Pharmacotherapy of inflammatory bowel disease.

The etiology, pharmacotherapy and management of the two major types of inflammatory bowel disease--ulcerative colitis and Crohn's disease--are reviewed. Sulfasalazine and topical corticosteroids (i.e., hydrocortisone, hydrocortisone acetate or methylprednisolone acetate) are effective in many patients with mild distal ulcerative colitis. Maintenance sulfasalazine therapy significantly reduces the relapse rate in ulcerative colitis. Systemic corticosteroids (i.e., prednisone, prednisolone or methylprednisolone) have improved the survival rate of patients with moderate and severe ulcerative colitis. Antacids should be given regularly during high-dose steroid therapy to prevent gastritis. If oral steroids are ineffective, the use of parenteral corticosteroids (hydrocortisone sodium succinate or methylprednisolone sodium succinate) is suggested. Both sulfasalazine and corticosteroids appear to be effective in the treatment of Crohn's disease but require further investigation, however, if patients fail to respond to this therapy, oral corticosteriods, in low dosages, given concomitantly with azathioprine (currently under evaluation) is suggested.

Colitis, Ulcerative↗