Presence Of Bile Research Articles

Cholesterol-phospholipid interactions resist the detergent effect of bovine bile

Sphingomyelin (SM) and cholesterol complexation gives rise to detergent-resistant liquid-ordered domains. The persistence of these domains and subsequent mixed micelle formation was examined in the presence of bile under physiological digestive in vitro conditions for vesicles comprising either SM/cholesterol, porcine brain phosphatidylcholine (BPC)/cholesterol, or soy phosphatidylcholine (SPC)/cholesterol bilayers, the latter two systems having no liquid-ordered domains. Micellization of these digested phospholipid multilamellar vesicle systems was confirmed by transmission electron microscopy. Bovine bile was found to consist of large multilamellar sheets which subsumed phospholipid vesicles to form aggregated superstructures. Budding off from these superstructures were vesicle-to-micelle transition intermediates: unilamellar vesicles and cylindrical micelles. The presence of cholesterol (60/40 phospholipid/cholesterol mol/mol) delayed the initial rapid onset of digestion, but not for BPC and SPC vesicle systems. Acyl chain order/disorder before and after vesicle-to-micelle transition of all three phospholipid/cholesterol systems was examined using Raman spectroscopy. The addition of bovine bile to both PC/cholesterol vesicle systems reduced the overall ratio of acyl chain disorder to order. In SM/cholesterol vesicles with ≤ 20% mol cholesterol, only the lateral inter-acyl chain packing was reduced, whereas for SM/cholesterol vesicles with ≥ 30% mol cholesterol, a higher proportion of gauche-to-trans isomerization was apparent, demonstrating that SM/cholesterol complexes modify the acyl chain structure of micelles.

Evidence for Involvement of the Salmonella enterica Z-Ring Assembly Factors ZapA and ZapB in Resistance to Bile.

Genes annotated as ygfE and yiiU in the genome of Salmonella enterica serovar Typhimurium encode proteins homologous to Escherichia coli cell division factors ZapA and ZapB, respectively. ZapA− and ZapB− mutants of S. enterica are bile-sensitive. The amount of zapB mRNA increases in the presence of a sublethal concentration of sodium deoxycholate (DOC) while zapA mRNA remains unaffected. Increased zapB mRNA level in the presence of DOC is not caused by upregulation of zapB transcription but by increased stability of zapB mRNA. This increase is suppressed by an hfq mutation, suggesting the involvement of a small regulatory RNA. We provide evidence that such sRNA is MicA. The ZapB protein is degraded in the presence of DOC, and degradation appears to involve the Lon protease. We propose that increased stability of zapB mRNA in the presence of DOC may counter degradation of bile-damaged ZapB, thereby providing sufficient level of functional ZapB protein to permit Z-ring assembly in the presence of bile.

Exoproteome Perspective on the Bile Stress Response of Lactobacillus johnsonii.

Probiotics must not only exert a health-promoting effect but also be capable of adapting to the harsh environment of the gastrointestinal (GI) tract. Probiotics in the GI tract must survive the cell wall-disrupting effect of bile acids. We investigated the exoproteome of Lactobacillus johnsonii PF01 and C1-10 under bile stress. A comparative analysis revealed the similarities between the two L. johnsonii exoproteomes, as well as their different responses to bile. The large number of metabolic proteins in L. johnsonii revealed its metabolic adaptation to meet protein synthesis requirements under bile stress. In addition, cell wall modifications occurred in response to bile. Furthermore, some extracellular proteins of L. johnsonii may have moonlighting function in the presence of bile. Enolase, L-lactate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, triosephosphate isomerase, 50s ribosomal protein L7/L12, and cellobiose-specific phosphotransferase system (PTS) sugar transporter were significantly upregulated under bile stress, suggesting a leading role in the collective bile stress response of L. johnsonii from its exoproteome perspective.

DksA coordinates bile-mediated regulation of virulence-associated phenotypes in type three secretion system-positive Vibrio cholerae.

In order to cause disease, pathogenic strains of Vibrio cholerae rely on intricate regulatory networks to orchestrate the transition between their native aquatic environment and the human host. For example, bacteria in a nutrient-starved environment undergo a metabolic shift called the stringent response, which is mediated by the alarmone ppGpp and an RNA-polymerase binding transcriptional factor, DksA. In O1 serogroup strains of V. cholerae, which use the toxin co-regulated pilus (TCP) and cholera toxin (CT) as primary virulence factors, DksA was reported to have additional functions as a mediator of virulence gene expression. However, little is known about the regulatory networks coordinating virulence phenotypes in pathogenic strains that use TCP/CT-independent virulence mechanisms. We therefore investigated whether functions of DksA outside of the stringent response are conserved in type three secretion system (T3SS)-positive V. cholerae. In using the T3SS-positive clinically isolated O39 serogroup strain AM-19226, we observed an increase in dksA expression in the presence of bile at 37 °C. However, DksA was not required for wild-type levels of T3SS structural gene expression, or for colonization in vivo. Rather, data indicate that DksA positively regulates the expression of master regulators in the motility hierarchy. Interestingly, the ΔdksA strain forms a less robust biofilm than the WT parent strain at both 30 and 37 °C. We also found that DksA regulates the expression of hapR, encoding a major regulator of biofilm formation and protease expression. Athough DksA does not appear to modulate T3SS virulence factor expression, its activity is integrated into existing regulatory networks governing virulence-related phenotypes. Strain variations therefore may take advantage of conserved ancestral proteins to expand regulons responding to in vivo signals and thus coordinate multiple phenotypes important for infection.

Antibiogram, Virulence Genes, and Biofilm-Forming Ability of Clinical Salmonella enterica Serovars: An In Vitro Study.

Salmonella enterica serovar Typhi and Salmonella Paratyphi are causative agents of enteric fever. Salmonella Typhi persists as a biofilm on gallstones. Hence, we studied the biofilm formation, antibiogram, and virulence genes of S. enterica serovars. Antibiogram of S. enterica serovars from human blood and stool samples were studied by Kirby-Bauer disk diffusion method and biofilm by microtiter plate method. We studied the minimum inhibitory concentration of the isolates by Vitek-2 semiautomated system. Polymerase chain reaction was done to detect invA and spvC genes. Of the 55 isolates studied, 36 (65.45%) were Salmonella Typhi, 13 (23.63%) were Salmonella Paratyphi A, 2 (3.64%) were Salmonella Typhimurium, and 4 (7.28%) were Salmonella spp. Resistance to ciprofloxacin and nalidixic acid were found to be 81.8% and 92.7%, respectively. Chloramphenicol and cotrimoxazole-susceptible strains were 98.18%. One each of Salmonella Typhi, Salmonella Paratyphi A, and S. enterica isolates formed weak biofilm at 28°C. However, at 37°C eight Salmonella Typhi produced weak biofilm in the presence of bile. One Salmonella Paratyphi A and two Salmonella spp. formed weak biofilm in the absence of bile. All the isolates had the invA gene. Salmonella Typhimurium had invA and spvC genes. Bile may contribute to biofilm formation and persistence of the Salmonella Typhi on gallstones, which may lead to carrier state. Changing antibiotic susceptibility pattern of Salmonella serovars is observed in our geographic area. The presence of invA and spvC genes indicate the ability of invasiveness and intracellular survival.

Freeze-drying of Enterococcus durans: Effect on their probiotics and biopreservative properties

The present work studied the preservation of probiotic strains of Enterococcus durans by freeze-drying. The prebiotic lactulose showed to be the best protectant agent for E. durans after freeze-drying and storage at 4 and 25 °C for 92 days. Freeze-dried E. durans LM01C01 was resistant to acid treatment and able to grow in the presence of bile. Also, freeze-dried samples grew in the presence of preservative food ingredients: potassium sorbate and sodium chloride. After addition of dried cultures in a cream cheese, the number of viable bacteria was maintained for 3 months (shelf-life of the products). The spent culture supernatant of E. durans LM01C01 showed inhibitory effects on the pathogens E. coli and S. aureus. Although the addition of dried probiotic to cream cheese did not have any effect on contamination of food matrix with E. coli, a drastic decrease of viability of S. aureus was observed. These results demonstrated the suitability of E. durans strains to develop a dried symbiotic product (probiotic plus prebiotic) that could be added to food matrices or nutraceutical products, that could also tolerate gastrointestinal conditions and may act as biopreservative too.

Grading operative findings at laparoscopic cholecystectomy following the new scoring system in Duhok governorate: Cross sectional study

IntroductionNumerous preoperative scoring systems predict difficult laparoscopic cholecystectomy. Recently, the intraoperative difficulties which are facing surgeons are studied. A new scoring system categorize patients according to many intraoperative findings with a final outcome whether converting to open cholecystectomy or continuing laparoscopically. Patients and methodsThis prospective study included 120 patients admitted for laparoscopic cholecystectomy for symptomatic gallstones from October 2019 to August 2020. Intraoperative difficulties were evaluated and patients were categorized according to intraoperative scoring for cholecystitis severity and compared depending to the rate of conversion to the open technique. ResultsMost patient were middle aged females having multiple gallstones, the mean operation time was 35 min and 7.8% of patients were converted to open cholecystectomy because of intraoperative difficulty.There was a significant correlation between the conversion rate and each of distended and/or contracted gall bladder, inability to grasp the gall bladder with traumatic forceps, stone ≥1 cm impacted in Hartman's pouch, and bile or pus outside gallbladder (P values: 0.002, 0.000, 0.008 and 0.015) respectively, and no significant correlation with gallbladder adhesions, adhesions from previous upper abdominal surgery, BMI>30, and Time to identify cystic artery and duct >90 min (P values: 0.123, 1, 1, 0.078) respectively. ConclusionNew intraoperative scoring systems are valuable in predicting difficulties and preventing increase operation time and possible injuries. The main points of difficulties are distended or contracted gallbladder, large stone impaction, difficult grasping the wall of the gall bladder and the presence of bile or pus outside the gall bladder.

BILOTHORAX: A RARE OCCURRENCE AFTER LAPAROSCOPIC GASTRIC SLEEVE RESECTION

SESSION TITLE: Medical Student/Resident Disorders of the Pleura Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Bilothorax is the presence of bile in the pleural space and represents a rare cause of pleural effusion of extra vascular origin (PEEVO). Most reported cases are primarily right sided and due to pleurobiliary fistula resulting from biliary tract injury, direct spread of infection from the liver, or trauma to the hepatobiliary tree or diaphragm. We present a unique case of a large left-sided bilothorax occurring one month after laparoscopic gastric sleeve resection complicated by splenic hematoma and hemoperitoneum without evidence of pleurobiliary fistula. CASE PRESENTATION: A 52-year-old woman presented with dyspnea and left sided abdominal pain 1 month after laparoscopic sleeve gastrectomy complicated by hemoperitoneum and splenic hematoma. Computed tomographic (CT) imaging was obtained and revealed a moderate, complex left-sided pleural effusion without associated ascites and decrease in splenic hematoma. A thoracentesis was performed which evacuated 800 milliliters of brownish-green pleural fluid. Bacterial and fungal cultures were negative. The pleural fluid was exudative by Light’s Criteria (Table 1) and fluid bilirubin was 2.6 mg/dL, compared to a serum total bilirubin level of 0.9 mg/dL, confirming a diagnosis of bilothorax. Given the persistence of complex effusion following thoracentesis, a 14 french pigtail catheter was inserted with significant improvement in the residual effusion. Dedicated assessment of the CT imaging revealed no evidence of abnormal connection between the pleural space and biliary tree. Therefore, the bilothorax was likely due to breakdown of the splenic hematoma with resorption into the pleural space. This theory was supported by no additional reaccumulation over the next three days. The patient was discharged and remains without pleural effusion. DISCUSSION: Bilothorax is primarily seen as a complication of invasive biliary procedures and typically presents as biliary peritonitis with associated right-sided pleural effusion. We describe a case of left-sided bilothorax presenting with dyspnea and no signs of biliary peritonitis or pleurobiliary fistula one month after a laparoscopic gastric sleeve resection complicated by splenic hematoma. We posit that breakdown and subsequent resorption of the hematoma across the diaphragm into the pleural space was the primary cause of effusion. To our knowledge, this is the first case to describe such a mechanism in the formation of a bilothorax. CONCLUSIONS: A high index of clinical suspicion is necessary for diagnosis of this PEEVO due to resorption of splenic hematoma across the diaphragm. Delay in diagnosis of bilothorax can result in serious pleural complications such as the development of complex fibrinous septations and empyema. Our patient did well with drainage alone and required no further surgical intervention. Reference #1: Jenkinson MRJ, Campbell W, Taylor MA. Bilothorax as a rare sign of intra-abdominal bile leak in a patient without peritonitis. Ann R Coll Surg Engl. 2013;95(7):e12–e13. doi:10.1308/003588413X13629960047678 DISCLOSURES: No relevant relationships by Ankur Aneja, source=Web Response No relevant relationships by Matt Schimmel, source=Web Response No relevant relationships by Keriann Van Nostrand, source=Web Response

Virulence Regulation and Innate Host Response in the Pathogenicity of Vibrio cholerae.

The human pathogen Vibrio cholerae is the causative agent of severe diarrheal disease known as cholera. Of the more than 200 “O” serogroups of this pathogen, O1 and O139 cause cholera outbreaks and epidemics. The rest of the serogroups, collectively known as non-O1/non-O139 cause sporadic moderate or mild diarrhea and also systemic infections. Pathogenic V. cholerae circulates between nutrient-rich human gut and nutrient-deprived aquatic environment. As an autochthonous bacterium in the environment and as a human pathogen, V. cholerae maintains its survival and proliferation in these two niches. Growth in the gastrointestinal tract involves expression of several genes that provide bacterial resistance against host factors. An intricate regulatory program involving extracellular signaling inputs is also controlling this function. On the other hand, the ability to store carbon as glycogen facilitates bacterial fitness in the aquatic environment. To initiate the infection, V. cholerae must colonize the small intestine after successfully passing through the acid barrier in the stomach and survive in the presence of bile and antimicrobial peptides in the intestinal lumen and mucus, respectively. In V. cholerae, virulence is a multilocus phenomenon with a large functionally associated network. More than 200 proteins have been identified that are functionally linked to the virulence-associated genes of the pathogen. Several of these genes have a role to play in virulence and/or in functions that have importance in the human host or the environment. A total of 524 genes are differentially expressed in classical and El Tor strains, the two biotypes of V. cholerae serogroup O1. Within the host, many immune and biological factors are able to induce genes that are responsible for survival, colonization, and virulence. The innate host immune response to V. cholerae infection includes activation of several immune protein complexes, receptor-mediated signaling pathways, and other bactericidal proteins. This article presents an overview of regulation of important virulence factors in V. cholerae and host response in the context of pathogenesis.

Glycocholic acid and butyrate synergistically increase vitamin D-induced calcium uptake in Caco-2 intestinal epithelial cell monolayers

BackgroundRoux-en-Y gastric bypass (RYGB) substantially decreases intestinal calcium absorption and may eventually lead to bone resorption. This is likely a consequence of bile diversion from the alimentary limb, as the presence of bile seems necessary for vitamin D-mediated calcium uptake. We recently suggested that the mediating mechanism may be a down-regulation of the vitamin D co-activator heat-shock protein (Hsp)90β. Recent evidence suggests that vitamin D may have effects on both active and passive calcium absorption. AimTo identify mechanisms in vitro that may be responsible for the decreased calcium absorption after RYGB. We hypothesized that bile, alone or in concert with nutritional compounds, could be of importance. Material & methodsCaco-2 cells were grown confluent on semi-permeable membranes in a double-chamber setup to mimic small intestinal mucosa. The effect of bile acids chenodeoxycholic, lithocholic, glycocholic and taurocholic acid, with and without the addition of the fatty-acid butyrate, were tested for their effects on Hsp90β expression and active and passive calcium-flux monitored using radioactive 45Ca. ResultsWe initially found that whole human bile, but only together with the fatty acid butyrate, potently induced Hsp90β expression. In line with this, a single bile acid, e.g. glycocholic acid (GCA), in combination with butyrate, increased Hsp90β expression (40 ± 13% vs. GCA, butyrate or vehicle alone; p < 0,001; n = 14–25). Further, this combination together with vitamin D increased the passive gradient-driven flux of calcium, compared to stimulation with vitamin D alone or in combination with either GCA or butyrate (880 ± 217% vs. vitamin D and GCA or butyrate, or vitamin D only; p = 0,01–0.006; n = 5–11). Surprisingly, this combination had no effect on active calcium transport in the absence of calcium gradient. ConclusionThe combination of GCA and butyrate increased gradient-driven calcium uptake up to 9-fold in Caco-2 intestinal epithelial cells, but had no effect on active calcium absorption. This effect was mediated via the vitamin D receptor co-activator Hsp90β.

Bile reflux in patients with nerd is associated with more severe heartburn and lower values of mean nocturnal baseline impedance and chemical clearance.

Mean nocturnal baseline impedance (MNBI) and postreflux swallow-induced peristaltic wave (PSPW) index are novel impedance-based markers of reflux, but the effect of bile reflux on these metrics is unknown. The aim of this study was to evaluate bile reflux, MNBI, and PSPW index in patients with endoscopy-negative GERD partially responsive to PPI therapy. All patients underwent off-PPI endoscopy, esophageal manometry, multichannel intraluminal impedance pH (MII-pH), and bile reflux monitoring. Abnormal esophageal acid exposure time (AET) was required for inclusion. Symptom intensity (using 10-cm visual analog scales), and conventional and novel MII-pH metrics were compared between patients with and without abnormal bile reflux. We evaluated 42 NERD patients (29 males, mean age: 53.4±13.years), mean AET 6.1±2%, of which 21 had abnormal bile reflux (Group A, 10.2±4.9%), and 21 had normal bile reflux (Group B, 0.4±0.1%, P<.05 compared with Group A). Heartburn reporting on PPI was higher in Group A (7.2±2.1 vs 5.8±0.9; P=.002), but AET, number of reflux events (acidic and weakly acidic), did not differ between the two groups. However, both PSPW index and MNBI were lower in Group A (P<.001). A strong inverse linear correlation was found between bile reflux and both MNBI (Pearson's test; R=-0.714; P<.001) and PSPW index (R=-0.722; P<.001). Compared to acid reflux alone, the presence of bile in an acidic esophageal environment is associated with more severe heartburn, lesser relief from PPI therapy, higher impairment of esophageal mucosal integrity and less effective chemical clearance.

Synthesis of Calcium Carbonate in the Presence of Bile, Albumen, and Amino Acids

The thermodynamic and experimental modeling of calcium carbonate crystallization in a model solution of human bile is performed. CaCO3 samples are synthesized in the presence of additives with variable additive concentrations. The phase and group-structure composition of the synthesized samples is determined by X-ray powder diffraction (XRD), Fourier-transform IR spectroscopy, and optical microscopy. Amorphous calcium carbonate and calcite are found to be primarily formed in the human bile model solution in the presence of glycine, glutamic acid, and albumen separately. When twenty amino acids and albumen are present in the highest concentrations permissible in the human body, vaterite is formed as the major phase. Distinctions in phase and group-structure compositions of samples are shown to occur depending on synthetic parameters. An effect is suggested to be caused by the compositions and concentrations of the additives used on the formation of a certain calcium carbonate polymorph.

Bile acids and ceramide overcome the entry restriction for GII.3 human norovirus replication in human intestinal enteroids

Human noroviruses (HuNoVs) cause sporadic and epidemic outbreaks of gastroenteritis in all age groups worldwide. We previously reported that stem cell-derived human intestinal enteroid (HIE) cultures support replication of multiple HuNoV strains and that some strains (e.g., GII.3) replicate only in the presence of bile. Heat- and trypsin-treatment of bile did not reduce GII.3 replication, indicating a nonproteinaceous component in bile functions as an active factor. Here we show that bile acids (BAs) are critical for GII.3 replication and replication correlates with BA hydrophobicity. Using the highly effective BA, glycochenodeoxycholic acid (GCDCA), we show BAs act during the early stage of infection, BA-dependent replication in HIEs is not mediated by detergent effects or classic farnesoid X receptor or Takeda G protein-coupled receptor 5 signaling but involves another G protein-coupled receptor, sphingosine-1-phosphate receptor 2, and BA treatment of HIEs increases particle uptake. We also demonstrate that GCDCA induces multiple cellular responses that promote GII.3 replication in HIEs, including enhancement of 1) endosomal uptake, 2) endosomal acidification and subsequent activity of endosomal/lysosomal enzyme acid sphingomyelinase (ASM), and 3) ceramide levels on the apical membrane. Inhibitors of endosomal acidification or ASM reduce GII.3 infection and exogenous addition of ceramide alone permits infection. Furthermore, inhibition of lysosomal exocytosis of ASM, which is required for ceramide production at the apical surface, decreases GII.3 infection. Together, our results support a model where GII.3 exploits rapid BA-mediated cellular endolysosomal dynamic changes and cellular ceramide to enter and replicate in jejunal HIEs.

The Efficacy of Autologous Myoblast Sheet Transplantation to Prevent Perforation After Duodenal Endoscopic Submucosal Dissection in Porcine Model

The recent advent of endoscopy has enabled the endoscopic submucosal dissection (ESD) of superficial nonampullary duodenal epithelial tumors. However, the substantially thin wall and presence of bile and pancreatic juice make it technically difficult to perform duodenal ESD without perforation, which leads to lethal complications. The present study evaluated the efficacy of autologous myoblast sheet transplantation for the prevention of late perforation after duodenal ESD in a porcine model. Two weeks before ESD, skeletal muscle was surgically excised from the femur of pigs, and myoblasts were isolated and seeded in temperature-responsive culture dishes to prepare sheets. Immediately after ESD, the autologous myoblast sheets were attached to the serosal surface at the ESD site with omentopexy. The pigs were divided into two groups: the autologous myoblast sheet group (n = 5), where the myoblast cell sheet was attached to the ESD ulcer part from the duodenal serous side, and the Omentum group (n = 5), where only the omentum was used. The pigs were sacrificed and analyzed macroscopically and histologically on postoperative day 3. The macroscopic examination of the abdominal cavity revealed perforation in the ESD ulcer area and leakage of bile in the Omentum group but no perforation in the Sheet group. A histopathological examination revealed that continuity of the duodenal wall at the ESD site was maintained with dense connective tissue in the Sheet group. In conclusion, autologous myoblast sheets were useful for preventing perforation after duodenal ESD.

Ιn Vitro Screening of γ-Aminobutyric Acid and Autoinducer-2 Signalling in Lactic Acid Bacteria Exhibiting Probiotic Potential Isolated from Natural Black Conservolea Olives.

In the present study, 33 strains of lactic acid bacteria (LAB) previously isolated from natural black Conservolea olives were assessed for their probiotic potential in vitro, as well as for their autoinducer-2 (AI-2) activity under standard growth conditions and the production of γ-aminobutyric acid (GABA). The probiotic tests included the in vitro resistance to low pH and resistance to bile salts, the evaluation of bile salt hydrolase activity, as well as safety tests regarding their possible haemolytic activity and their antimicrobial activity against pathogens. The results indicated that 17 strains were able to survive in low pH and in the presence of bile, with 15 of them also exhibiting partial bile salt hydrolase activity. None of the strains exhibited haemolytic activity or inhibited the growth of any of the examined pathogens. Moreover, the strains displayed generally low AI-2 activity under the growth conditions tested, regardless of the species. Interestingly, in contrast to what has been found in most foods, none of the isolates were found to produce GABA after 48 h of growth. The results from the AI-2 activity and extracellular GABA detection were considered as unexpected for LAB with probiotic attributes.

Investigation of drug-polymer miscibility, biorelevant dissolution, and bioavailability improvement of Dolutegravir-polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer solid dispersions

The aim of the current study was to prepare the efficacious amorphous solid dispersion of poorly water-soluble compound, Dolutegravir. After theoretical and experimental determination of drug-polymer miscibility, polyvinyl caprolactam-polyvinyl acetate-polyethylne glycol graft copolymer was chosen as a polymer. The solid dispersions of Dolutegravir were prepared by quench cooling and solvent evaporation method. Though quench cooling successfully stabilized the drug into amorphous form, solvent evaporation technique failed to render the drug completely amorphous. Owing to the negative Gibbs free energy at room temperature, the prepared dispersions were found stable at room temperature for 60 days. To resolve the overlapping contribution of micellar solubilization and amorphicity in improving the dissolution characteristics of Dolutegravir, the in vitro dissolution studies were performed in USP phosphate buffer as well as bio-relevant media. The dissolution advantage between prepared dispersions and pure drug in USP phosphate buffer was found bridged in the bio-relevant media. For this, the micellar solubilization driven dissolution of Dolutegravir in the presence of bile and lecithin micelles was thought as a contributing factor. Nevertheless, the dissolution advantage of dispersions prepared by quench cooling method was found endured in FeSSIF, which was thought to be due to its amorphicity leading to molecular level dissolution. Subsequently, the dissolution advantage was translated into the improved flux. Further, in vivo oral bioavailability was investigated for the dispersion prepared by quench cooling by using crystalline Dolutegravir as a control. The overall exposure of Dolutegravir was improved by 1.7 fold (AUC), while the maximum plasma concentration (Cmax) demonstrated 2 fold increase after comparing with crystalline Dolutegravir.

Clinical, Endoscopic, and Histologic Findings at the Distal Esophagus and Stomach Before and Late (10.5Years) After Laparoscopic Sleeve Gastrectomy: Results of a Prospective Study with 93% Follow-Up.

Perform a prospective study based on sequential clinical, endoscopic, and histologic evaluations of the foregut late after laparoscopic sleeve gastrectomy (LSG) in obese patients. After LSG, several studies have suggested an increase in the incidence of clinical gastroesophageal reflux (GERD) while others have reported an improvement but based mainly on clinical questionnaires. Prospective study of 104 consecutive patients submitted to LSG. Several postoperative endoscopic and histologic evaluations of the esophagogastric junction (EGJ) and the gastric tube (GT) were performed and correlated with symptomatic findings. According to clinical preoperative findings, patients were divided into non-refluxers (Group I) and refluxers (Group II). Seven patients were unreachable, leaving 97 (93%) for late evaluation. Among Group I, 58.5% developed de novo GERD, while in Group II just 13.6% showed the disappearance of them. Endoscopic evaluations showed progressive deterioration of the EGJ in Group I, with the development of erosive esophagitis (EE), hiatal hernia (HH), and dilated cardia in a large proportion of them. In the GT, the presence of bile was seen in 40%, and an open immobile pylorus was detected in 82%. Short-segment Barrett's esophagus (BE) appeared in 4%. Patients submitted to LSG showed a significant and progressive increase in the presence of "de novo" GERD. Also, an increased duodenogastric reflux was seen through an open and immobile pylorus. Therefore, based on these results, it seems like LSG is a "pro-reflux" surgical procedure, which should be continuously evaluated late after surgery.

2772 Choleperitoneum Due to Gastric Perforation Masquerading as Acute Pancreatitis in a Roux-En-Y Gastric Bypass Patient

INTRODUCTION: Approximately 200,000 patient undergo weight loss surgery in the United States annually. Nearly half undergo Roux-en-Y gastric bypass (RYGB). After RYGB, bile acid may reflux into the gastric remnant resulting in inflammation and occasionally, perforation. The prevalence of this complication in RYGB is under 1%. We present a patient with RYGB who was initially diagnosed with pancreatitis. When the patient did not respond to treatment, reevaluation revealed gastric perforation resulting in choleperitoneum. Physicians should be aware of complications related to weight loss surgery. CASE DESCRIPTION/METHODS: A 68-year-old lady with RYGB, cholecystectomy, and osteoarthritis, recently treated with naproxen 500 mg BID, presented with sudden onset sharp, continuous, 8 / 10, epigastric pain radiating to the right upper quadrant. She had no alleviating or aggravating factor. She had no associated nausea, vomiting, sweats or chills. Vital signs were unremarkable. Her abdomen was not distended. BS present. She had no pain to percussion, but tender to palpation in the epigastric region. Initial labs demonstrated WBC 14,800/mm3, AST 12 U/L; ALT 21 U/L; amylase 1,761 U/L and lipase 926 U/L. CT demonstrated a small volume of ascites, but no fat stranding or inflammation of the pancreas. A clinical diagnosis of pancreatitis due to naproxen was made. Despite conservative treatment, the patient deteriorated. Her abdomen became distended. Repeat CT demonstrated a large volume of ascites. Analysis of ascitic fluid revealed RBC 2/mm3; WBC 4/mm3; albumin 1.1 gm/dL with SAAG 0.9 gm/dL; and total bilirubin 7.5mg/dL. Choleperitonitis was diagnosed. Emergent laparotomy revealed a gastric perforation of the remnant stomach which was surgically repaired. DISCUSSION: Choleperitoneum is defined as the presence of bile in the peritoneum. An ascitic fluid bilirubin concentration greater than 6 mg/dL with an ascitic fluid/serum bilirubin ratio greater than 1.0 is diagnostic. Etiologies include liver laceration, gall bladder rupture, or bile duct leak. Amylase and lipase may be elevated. The clues suggesting an alternative diagnosis to pancreatitis was the sudden onset of pain (consistent with rupture of viscus) and normal appearing pancreas on CT despite elevations of amylase and lipase and a small collection of ascites. Physicians should keep in mind the prevalence and complications of weight loss surgery when evaluating abdominal pain.

Exposure to Bile Leads to the Emergence of Adaptive Signaling Variants in the Opportunistic Pathogen Pseudomonas aeruginosa.

The chronic colonization of the respiratory tract by the opportunistic pathogen Pseudomonas aeruginosa is the primary cause of morbidity and mortality in cystic fibrosis (CF) patients. P. aeruginosa has been shown to undergo extensive genomic adaptation facilitating its persistence within the CF lung allowing it to evade the host immune response and outcompete co-colonizing residents of the lung microbiota. However, whilst several studies have described the various mutations that frequently arise in clinical isolates of P. aeruginosa, the environmental factors governing the emergence of these genetic variants is less well characterized. Gastro-oesophageal reflux has recently emerged as a major co-morbidity in CF and is often associated with the presence of bile acids in the lungs most likely by (micro) aspiration. In order to investigate whether bile may select for genetic variants, P. aeruginosa was experimentally evolved in artificial sputum medium, a synthetic media resembling environmental conditions found within the CF lung. Pigmented derivatives of P. aeruginosa emerged exclusively in the presence of bile. Genome sequencing analysis identified single nucleotide polymorphisms (SNPs) in quorum sensing (lasR) and both the pyocyanin (phzS) and pyomelanin (hmgA) biosynthetic pathways. Phenotypic analysis revealed an altered bile response when compared to the ancestral P. aeruginosa progenitor strain. While the recovered pigmented derivatives retained the bile mediated suppression of swarming motility and enhanced antibiotic tolerance, the biofilm, and redox responses to bile were abolished in the adapted mutants. Though loss of pseudomonas quinolone signal (PQS) production in the pigmented isolates was not linked to the altered biofilm response, the loss of redox repression could be explained by defective alkyl-quinolone (AQ) production in the presence of bile. Collectively, these findings suggest that the adaptive variants of P. aeruginosa that arise following long term bile exposure enables the emergence of ecologically competitive sub-populations. Altered pigmentation and AQ signaling may contribute to an enhancement in fitness facilitating population survival within a bile positive environment.

Characterization of Salmonella resistance to bile during biofilm formation

Non-typhoid Salmonella infection may present as acute gastroenteritis or chronic infection, primarily in the bile-rich gallbladder. Biofilm formation is a mechanism of bile resistance in Salmonella. Our aim was to determine how Salmonella utilizes bile as a signal, and to study the relevance of the interaction between the PhoP-PhoQ two-component system and cyclic diguanosine monophosphate (c-di-GMP) signaling to biofilm formation. Two-dimensional (2-D) gel electrophoresis was used to identify genes required for Salmonella biofilm formation in bile. Quantitative real-time PCR (qRT-PCR) was used to clarify the role of the PhoP-PhoQ two-component system and its interaction with genes involved in the c-di-GMP network during biofilm formation. Our result revealed that Salmonella mutants with incomplete outer membrane (△ompA), defective flagella (△flgE), or incomplete PhoP-PhoQ two-component system (△phoP), were unable to develop complete biofilms in the presence of bile. Moreover, PhoP-PhoQ two-component system-related Salmonella mutants (△phoP, △phoQ, △phoP△phoQ) had lower expression of c-di-GMP related genes (csgD, adrA) than the wild-type Salmonella strain had in the bile environment. Salmonella may sense and respond to bile through the PhoP-PhoQ two-component system during biofilm formation. Furthermore, the PhoP-PhoQ two-component system might activate regulators of the c-di-GMP signaling network.