Do intraoperative pyloric interventions predict the need for postoperative endoscopic interventions after minimally invasive esophagectomy?

Intraoperative pyloric procedures are often performed during esophagectomies to reduce the rates of gastric conduit dysfunction. They include pyloroplasty (PP), pyloromyotomy (PM), and pylorus botulinum toxin type-A injections (BI). Despite these procedures, patients frequently warrant further endoscopic interventions. The aim of this study is to compare intraoperative pyloric procedures and the rates of postoperative endoscopic interventions following minimally invasive esophagectomy (MIE). We identified patients who underwent MIE for esophageal carcinoma and grouped them as 'None' (no intervention), 'PP', 'PM', or 'BI' based on intraoperative pyloric procedure type. The rates of endoscopic interventions for the first six postoperative months were compared. To adjust for variability due to MIE type, the rates of >1 interventions were compared using a zero-inflated Poisson regression analysis. Significance was established at P < 0.05. There were 146 patients who underwent an MIE for esophageal cancer from 2008 to 2015; 77.4% were three-hole MIE, and 22.6% were Ivor- Lewis MIE. BI was most frequent in Ivor-Lewis patients (63.5%), while PP was most frequent (46.9%) in three-hole patients. Postoperative endoscopic interventions occurred in 38 patients (26.0%). The BI group had the highest percentage of patients requiring a postoperative intervention (n = 13, 31.7%). After adjusting for higher rates of interventions in three-hole MIE patients, the BI and None groups had the lowest rates of >1 postoperative interventions. Our data did not show superiority of any pyloric intervention in preventing endoscopic interventions. The patients who received BI to the pylorus demonstrated a trend toward a greater likelihood of having a postoperative intervention. However when adjusted for type of MIE, the BI and None groups had lower rates of subsequent multiple interventions. Further research is needed to determine if the choice of intraoperative pyloric procedure type significantly affects quality of life, morbidity, and overall prognosis in these patients.

Cloning and identification of the Escherichia coli murB DNA sequence, which encodes UDP-N-acetylenolpyruvoylglucosamine reductase.

The murB gene, which complemented the UDP-N-acetylenolpyruvoylglucosamine reductase (EC 1.1.1.158) mutation in Escherichia coli ST5, was cloned from an E. coli chromosomal library. murB was subcloned on a 2.8-kb PvuII fragment into pUC19 and sequenced. A 1,029-bp open reading frame encoded a 342-amino-acid polypeptide of 37,859 Da. A DNA sequence homology search revealed that murB had almost 100% homology with a previously reported unidentified open reading frame, ORFII, at 89.9 min. Physical and genetic mapping results were consistent with this map position, and minicell analyses of murB subclones showed a plasmid-encoded protein of approximately 37,000 Da, which closely matched the calculated size of the murB protein.

Molecular cloning and characterization of the glucosyltransferase C gene (gtfC) from Streptococcus mutans LM7.

A glucosyltransferase (GTF) gene, designated gtfC, was cloned from Streptococcus mutans LM7. Its gene product was detected by screening a bacteriophage lambda library with rabbit antiserum raised against S. mutans LM7 extracellular proteins. DNA isolated from the immunopositive recombinant phage revealed two S. mutans chromosomal EcoRI fragment inserts, 8.1 and 4.7 kilobase pairs in size. Escherichia coli minicell analyses revealed the approximate position and direction of transcription of the gtfC gene. The gene product was determined to be a polypeptide of about 150 kilodaltons which synthesized a water-soluble glucan. Restriction endonuclease mapping and DNA hybridization indicated a repeated region of DNA corresponding to a portion of the coding region of gtfC immediately downstream from the intact gtfC locus on the chromosome. A 300-base-pair gtfC-specific probe showed that the gene and the putative duplicated sequence were present in S. mutans serotypes c, e, and f, but not in other related oral streptococci which had GTF activity. In addition, the gtfC determinant displayed homology to sequences corresponding to the carboxy-terminal coding region of a gene (gtfB) encoding a GTF activity that synthesized water-insoluble glucans. These data suggest that at least one class of GTF genes may be present in multiple copies in S. mutans and, further, that GTF genes may contain conserved sequences internal to their coding regions.

Molecular organization and expression of the gtfA gene of Streptococcus mutans LM7.

The Streptococcus mutans LM7 gene gtfA was cloned in Escherichia coli along with flanking regions of the chromosome as a fragment representing 10.3 kilobases (kb) of streptococcal DNA. Restriction endonuclease mapping revealed that the cloned DNA consisted of four EcoRI fragments with gtfA sucrase activity localized to one fragment, EcoRI-B (2.4 kb). Subsequent analysis with E. coli minicells indicated that three polypeptides were encoded on the 10.3-kb insert (55 [GtfA], 45, and 35 kilodaltons). Neither the 45- nor 35-kilodalton polypeptide exhibited any detectable sucrase activity. The approximate positions and directions of transcription of the two larger proteins were determined from minicell protein profiles displaying truncated versions of these polypeptides. The restriction endonuclease data for the cloned gtfA gene were used to develop a strategy for insertional inactivation of this locus in vivo. An internal HincII fragment of the gtfA gene was removed and replaced with a DNA fragment containing a tetracycline resistance determinant. This new recombinant plasmid was linearized and then transformed into S. mutans GS5 and S. mutans V403 where it was incapable of replication. It was predicted that Tcr colonies would result from double-crossover recombinational events involving homologous regions flanking the gtfA gene. This was verified by Southern DNA hybridization analyses. The inactivation of the gtfA gene in both S. mutans GS5 and S. mutans V403 resulted in a decrease of water-soluble exopolysaccharide but no detectable changes in the amounts of water-insoluble polymers.

Human serum antibody response against Streptococcus mutans antigens.

Antigens from Streptococcus mutans were examined to identify specific polypeptides that may have stimulated antibody responses and possibly play some role in caries immunity. A group of 10 adult human subjects was screened for serum antibodies reactive with antigens from S. mutans. Extracellular and cellular protein preparations from S. mutans LM7 (Bratthall serotype e) and V403 (biotype c) were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by Western electrophoretic transfer and immunoblotting analysis. Antibodies reactive with polypeptides ranging from 34 to 400 kilodaltons in apparent molecular mass were detected by these means. Radioimmunoassay competition experiments revealed that the cellular and extracellular antigens did not compete with each other for serum antibodies. Preabsorption of sera with extracellular proteins from other oral streptococcal species prior to immunoblotting indicated that the antigens unique to S. mutans have molecular masses greater than 100 kilodaltons, and each individual produced antibodies against different antigens of high molecular mass. Examination of sera from young children also indicated heterogeneous responses against S. mutans LM7 antigens.