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Biomedical subjects

A F Parker

Publications and source records attributed to A F Parker.

4 recordsLinked to original sources
PubMed1993

Bacteriophage Lambda as a Delivery Vector for Tn10-Derived Transposons in Xenorhabdus bovienii.

Xenorhabdus bovienii wild-type strains lack a functional receptor protein (LamB) in the outer membrane and as a result are unable to adsorb coliphage lambda (lambda). Introduction of plasmids encoding lamB into X. bovienii T228 results in constitutive expression of LamB in the outer membrane of this organism. LamB-expressing strains of X. bovienii adsorb lambda bacteriophage particles and can be used as hosts for lambda::Tn constructs. A Tn10-derived transposon, element 9 (J. C. Way, D. Davis, D. Morisato, D. E. Roberts, and N. Kleckner, Gene 32:369-379, 1984) was used to construct a variety of insertion mutants of X. bovienii. Mutants that had altered expression of protease, lipase, DNase, dye-binding capability, and hemolytic activity, in addition to a series of auxotrophic mutants, were isolated.

Journal Article↗
PubMed1979

Incidence and significance of gastroesophageal reflux following repair of esophageal atresia and tracheoesophageal fistula and the need for anti-reflux procedures.

Patients with esophageal atresia and/or tracheoesophageal fistula are known to have disordered esophageal motility, but the incidence of significant gastroesophageal reflux requiring anti-reflux surgery remains undocumented. We have studied a series of patients from 2 wk to 13 yr post-repair, utilizing manometric motility and acid reflux techniques. All demonstrated abnormalities of esophageal motility, including aperistalsis, low amplitude contraction, and simultaneous contractions. Lower esophageal sphincter pressures ranged from 7 to 50 mm Hg. Fourteen patients demonstrated signifcant reflux and six patients required anti-reflux surgery for recurrent pneumonia or recurrent stricture. The incidence of significant gastroesophageal reflux requiring antireflux surgery appears significant following repair of esophageal atresia and/or tracheoesophageal fistula.

Child↗
PubMed1978

Use of intraoperative esophageal manometrics in surgical treatment of gastroesophageal reflux in pediatric patients.

Intraoperative lower esophageal sphincter (LES) pressures and lenghts were measured in 10 pediatric patients requiring surgery for compications of gastroesophageal reflux. LES pressure changed significantly pre- and post-Nissen fundoplication (9.8 +/- 1.51 mm Hg vs. 32.8 +/- 2.68 mm Hg, p less than 0.001). LES length also showed a significant change (1.3 +/- 0.13 cm vs. 2.8 +/- 0.26 cm, p less than 0.001). One week postoperatively LES pressures were significantly greater than preoperative values (26.4 +/- 1.74 mm Hg vs. 15.6 +/- 2.64 mm Hg, p less than 0.01). Eight of 10 patients have been evaluated 6 mo post fundoplication. None has gastroesophageal reflux by acid reflux testing or water siphon barium esophagram. None of the 10 patients has had gas bloat syndrome during the follow-up period.

Adolescent↗