Optimal Chest Drainage Method After Anatomic Lung Resection: A Prospective Observational Study.

BACKGROUND: Several methods for chest drainage after pulmonary resection of malignant lung tumors exist, but consensus on the ideal method has not been reached. METHODS: We conducted a multicenter prospective observational study. We enrolled 2200 patients who underwent lung resection for lung tumors. Of the 1470 patients who underwent anatomic resection, 347 showed air leak on the morning of postoperative day 1. They were assigned to 3 groups according to the chest drainage method on postoperative day 1. RESULTS: Of 347 patients with postoperative air leaks, 107 (30.8%), 179 (51.6%), and 61 (17.6%) were assigned to water seal, continuous suction, and digital drainage, respectively. The median postoperative air leak duration was significantly longer with digital drainage (4.0 days) than with either water seal (2.5 days) or continuous suction (3.0 days; P = .009). Chest tubes were required for significantly more days on average with digital drainage (6.0 days) than with water seal (4.0 days) or continuous suction (4.0 days; P = .003). Prolongation of air leak duration was significantly more likely to occur in patients with body mass index <18.5 kg/m2 (hazard ratio [HR], 1.6; 95% CI, 1.1-2.3), moderate or severe air leak on postoperative day 1 (HR, 2.0; 95% CI, 1.5-2.6), or digital drainage (HR, 1.4; 95% CI, 1.01-1.9). CONCLUSIONS: Water seal was associated with significantly shorter duration of postoperative air leak and chest drainage compared with continuous suction and digital drainage.

Left upper lobectomy for cancer of the left lung with a rare mediastinal left basal pulmonary artery.

We report a rare case wherein a mediastinal left basal pulmonary artery was detected during surgery. Intraoperative findings revealed mediastinal left lingular and basal segments of the pulmonary artery (A4+5 + A8-10) just dorsal to the superior pulmonary vein. The mediastinal left basal pulmonary artery is classified by its branching type, (1) complete type-wherein the entire that all basal pulmonary artery flow lies between the superior pulmonary vein and the left upper bronchus, as in like this case, (2) incomplete type-wherein that a part of the left basal pulmonary artery segment is on the flow mediastinal side. It is important to understand this rare aberration for undergoing safe surgery.

PhoB regulates the survival of Bacteroides fragilis in peritoneal abscesses.

In response to phosphate limitation, bacteria employ the Pho regulon, a specific regulatory network for phosphate acquisition. The two-component signal transduction system of PhoRB plays a crucial role in the induction of Pho regulon genes, leading to the adaptation to phosphate starvation. Herein, we identified the PhoRB system in Bacteroides fragilis, a commensal gut bacterium, and evaluated its role in gut colonization and survival in peritoneal abscesses. BF1575 and BF1576 encoded PhoR (sensor histidine kinase) and PhoB (response regulator) in the sequenced B. fragilis strain YCH46, respectively. Transcriptome analysis revealed that deletion of phoB affected the expression of 585 genes (more than 4-fold change) in B. fragilis, which included genes for stress response (chaperons and heat shock proteins), virulence (capsular polysaccharide biosynthesis) and phosphate metabolism. Deletion of phoB reduced the ability of the bacterium to persist in peritoneal abscesses induced by an intra-abdominal challenge of B. fragilis. Furthermore, PhoB was necessary for survival of this anaerobe in peritoneal abscesses but not for in vitro growth in rich media or in intestinal colonization. These results indicate that PhoB plays an important role in the survival of B. fragilis under stressful extraintestinal conditions.

Utilization of titanium oxide-like compound as an inorganic phosphate adsorbent for the control of serum phosphate level in chronic renal failure.

Hyperphosphatemia adversely affects the prognosis of patients with chronic renal failure (CRF). We synthesized a titanium oxide-like compound (TAP) as a phosphate adsorbent for treatment of hyperphosphatemia in CFR patients. We evaluated the ability of TAP to adsorb inorganic phosphate in vitro and in vivo. TAP was shown to contain sulfate and hydroxyl groups by thermal analysis, which probably involved in phosphate adsorption through an ionic exchange mechanism. TAP constantly adsorbed phosphate (66.20-72.84 mg/g TAP) over a wide pH range (1.22-7.27) in vitro. To evaluate the phosphate binding potential of TAP in vivo, adenine-induced CRF rats were fed AIN-76 diet containing 3% TAP, 10% TAP, 3% sevelamer hydrochloride (clinical phosphate adsorbent), or 3% calcium carbonate, and serum levels of phosphate and calcium and urinary phosphate were compared with those in untreated CRF rats. Orally administered TAP showed the inhibitory effect on serum phosphate level in adenine-induced CRF rats, which was equivalent to that of sevelamer hydrochloride. These results indicate that TAP is a useful alternative phosphate-binder with fewer side effects than sevelamer hydrochloride and calcium carbonate.

Efficient electrotransformation of Bacteroides fragilis.

This study describes refined electroporation parameters for efficient transformation of Bacteroides fragilis by plasmids prepared from laboratory strains of Escherichia coli. Development of the method used included determination of the optimal growth conditions for competent cell preparation, selectable antimicrobial resistance markers, electric field strength, and postpulse incubation time. Of the four E. coli-Bacteroides shuttle plasmids tested (pVAL-1, pVAL-2, pNLY1, and pLYL05), pLYL05 containing the cefoxitin resistance marker was found to be the most suitable for B. fragilis transformation, and it generated 2- to 900-fold more transformants (about 10(4) transformants per microg pLYL05 DNA) than the other plasmids. For the 72-h cultivation period tested, B. fragilis cells harvested at 48 h yielded the highest numbers of transformants. The transformation efficiency of pLYL05 increased linearly with the electric field strength over a range from 5.0 to 12.5 kV/cm. At least 3 h of postpulse incubation was required to maximize the transformation efficiency. For deletion of B. fragilis genes by homologous recombination, competent cells grown to early exponential phase and 12 h of postpulse incubation were required for efficient integration of the pLYL05-based suicide vector into the target site. The expected integration was obtained in B. fragilis strain NCTC9343 only when a homologously prepared (i.e., in vivo methylated) suicide vector was used. Spontaneous resolution of the diploid successfully deleted the expected genetic region. Our simple and efficient plasmid transfer method enabled disruption of a B. fragilis gene using in vivo-methylated targeted vectors. Our optimized electroporation parameters provide a useful tool for genetic manipulation of Bacteroides species.

Identification of the site-specific DNA invertase responsible for the phase variation of SusC/SusD family outer membrane proteins in Bacteroides fragilis.

The human gut microbe Bacteroides fragilis can alter the expression of its surface molecules, such as capsular polysaccharides and SusC/SusD family outer membrane proteins, through reversible DNA inversions. We demonstrate here that DNA inversions at 12 invertible regions, including three gene clusters for SusC/SusD family proteins, were controlled by a single tyrosine site-specific recombinase (Tsr0667) encoded by BF0667 in B. fragilis strain YCH46. Genetic disruption of BF0667 diminished or attenuated shufflon-type DNA inversions at all three susC/susD genes clusters, as well as simple DNA inversions at nine other loci, most of which colocalized with susC/susD family genes. The inverted repeat sequences found within the Tsr0667-regulated invertible regions shared the consensus motif sequence AGTYYYN(4)GDACT. Tsr0667 specifically mediated the DNA inversions of 10 of the 12 regions, even under an Escherichia coli background when the invertible regions were exposed to BF0667 in E. coli cells. Thus, Tsr0667 is an additional globally acting DNA invertase in B. fragilis, which probably involves the selective expression of SusC/SusD family outer membrane proteins.