ABSTRACT
BACKGROUND/PURPOSE: Anastomotic leak and stricture are common causes of morbidity after esophageal repair. The authors describe a technique of patch esophagoplasty using decellularized human skin. METHODS: Twelve conditioned dogs underwent a cervical 2.0- x 1.0-cm esophagoplasty with AlloDerm. A gastrostomy tube was used for feedings until an esophagram was performed on the 10th to 14th postoperative day. Dogs were then given oral chow and followed up for leak and dysphagia. Animals were killed at 1-, 2-, and 3-month intervals and evaluated for stricture, diverticula formation, and patch histology. RESULTS: All animals survived, and none had sepsis or dysphagia. All esophagrams were without evidence of leak or stricture. At death there were no strictures or diverticula. Histologic examination of 1-month specimens showed partial reepithelialization of the patch with neovascularization. Control staining of AlloDerm was strongly positive for elastin. This was decreased in the region of the patch at 1 month. Two-month specimens showed intact epithelium and an increase in the caliber of new blood vessels. Three-month specimens showed no significant variation from 2-month animals. CONCLUSION: Decellularized human skin (AlloDerm) provides a temporary collagen framework on which esophageal healing can occur and function can be maintained.
Subject(s)
Esophagoplasty/methods , Skin Transplantation/methods , Animals , Collagen , Dogs , Esophageal Stenosis/therapy , Humans , Postoperative Period , Plastic Surgery Procedures/methodsABSTRACT
Transport processes are used by all organisms to obtain essential nutrients and to expel wastes and other potentially harmful substances from cells. Such processes are important means by which resistance to selected antimicrobial agents in bacteria is achieved. The recently described Staphylococcus aureus norA gene encodes a membrane-associated protein that mediates active efflux of fluoroquinolones from cells. SA-1199B is a fluoroquinolone-resistant strain of S. aureus from which we cloned an allele of norA (norA1199). Similar to that of norA, the protein product of norA1199 preferentially mediates efflux of hydrophilic fluoroquinolones in both S. aureus and an Escherichia coli host, a process driven by the proton motive force. Determination of the nucleotide sequence of norA1199 revealed an encoded 388-amino-acid hydrophobic polypeptide 95% homologous with the norA-encoded protein. Significant homology with other proteins involved in transport processes also exists, but especially with tetracycline efflux proteins and with the Bacillus subtilis Bmr protein that mediates active efflux of structurally unrelated compounds, including fluoroquinolones. In S. aureus, the norA1199-encoded protein also appears to function as a multidrug efflux transporter. Southern hybridization studies indicated that norA1199 (or an allele of it) is a naturally occurring S. aureus gene and that related sequences are present in the S. epidermidis genome. The nucleotide sequence of the wild-type allele of norA1199, cloned from the fluoroquinolone-susceptible parent strain of SA-1199B, did not differ from that of norA1199 throughout the coding region. Northern (RNA) and Southern hybridization studies showed that increased transcription, and not gene amplification, of norA1199 is the basis for fluoroquinolone resistance in SA-1199B.
Subject(s)
Anti-Infective Agents/pharmacology , Bacterial Proteins/genetics , Carrier Proteins/genetics , Staphylococcus aureus/drug effects , Amino Acid Sequence , Anti-Infective Agents/pharmacokinetics , Bacterial Proteins/isolation & purification , Base Sequence , Blotting, Northern , Blotting, Southern , Carrier Proteins/isolation & purification , Cloning, Molecular , DNA, Bacterial/isolation & purification , Drug Resistance, Microbial , Electrophoresis, Gel, Pulsed-Field , Microbial Sensitivity Tests , Molecular Sequence Data , Norfloxacin/metabolism , Staphylococcus aureus/geneticsABSTRACT
Fluoroquinolone resistance that arose in the test strain during ciprofloxacin therapy of experimental Staphylococcus aureus endocarditis was studied. In two isolates, resistance was due to a decreased sensitivity of the process of DNA synthesis to fluoroquinolones, suggesting the presence of an altered DNA gyrase. Another isolate had an enhanced energy-dependent mechanism, possibly an efflux system, by which cell-associated [3H]norfloxacin was reduced. When a 2.7-kb SphI-KpnI chromosomal fragment from this organism was cloned into pUC19, fluoroquinolone resistance was expressed in an Escherichia coli host, and such organisms acquired an energy-dependent ability to reduce cell-associated [3H]norfloxacin. Lack of homology between this DNA and other cloned gyrA genes indicated that its protein products are distinct from the gyrA protein. S. aureus has the capability of decreasing the quantity of cell-associated fluoroquinolone. An enhancement of this system by an as yet undefined mechanism and an alteration in DNA gyrase are two means by which this organism can develop resistance to fluoroquinolones.
