Hemosuccus Pancreaticus following a Puestow Procedure in a Patient with Chronic Pancreatitis.

PubMed

Okamoto, Hirotaka; Miura, Kazuo; Fujii, Hideki

2011-05-01

Hemosuccus pancreaticus is an unusual cause of gastrointestinal bleeding that occurs as a complication of chronic or acute pancreatitis. We report a case of extremely acute-onset hemosuccus pancreaticus occurring in a patient with chronic pancreatitis over a long-term follow-up after a Puestow procedure (side-to-side pancreaticojejunostomy). The patient was admitted to our hospital due to severe anemia and tarry stools indicative of gastrointestinal bleeding. Emergent endoscopy, including gastrointestinal fiberscopy and colon fiberscopy, showed no abnormal findings. Abdominal contrast-enhanced computed tomography and hemorrhagic scintigraphy did not detect a hemorrhagic lesion. Although interventional radiology was considered for diagnosis and treatment, conservative therapy seemed sufficient to affect hemostasis. Two weeks later, however, acute intestinal bleeding with hemodynamic shock occurred, and exploration was performed without delay. Intraoperative endoscopy through an incision of the reconstructed jejunal loop in the close proximal end revealed a site of active bleeding from the side-to-side anastomotic pancreatic duct. Following a longitudinal incision of the jejunal loop, a bleeding point was sutured and ligated on direct inspection. The patient showed a good postoperative course.

The growth pattern of the human intestine and its mesentery.

PubMed

Soffers, Jelly H M; Hikspoors, Jill P J M; Mekonen, Hayelom K; Koehler, S Eleonore; Lamers, Wouter H

2015-08-22

It remains unclear to what extent midgut rotation determines human intestinal topography and pathology. We reinvestigated the midgut during its looping and herniation phases of development, using novel 3D visualization techniques. We distinguished 3 generations of midgut loops. The topography of primary and secondary loops was constant, but that of tertiary loops not. The orientation of the primary loop changed from sagittal to transverse due to the descent of ventral structures in a body with a still helical body axis. The 1st secondary loop (duodenum, proximal jejunum) developed intraabdominally towards a left-sided position. The 2nd secondary loop (distal jejunum) assumed a left-sided position inside the hernia before returning, while the 3rd and 4th secondary loops retained near-midline positions. Intestinal return into the abdomen resembled a backward sliding movement. Only after return, the 4th secondary loop (distal ileum, cecum) rapidly "slid" into the right lower abdomen. The seemingly random position of the tertiary small-intestinal loops may have a biomechanical origin. The interpretation of "intestinal rotation" as a mechanistic rather than a descriptive concept underlies much of the confusion accompanying the physiological herniation. We argue, instead, that the concept of "en-bloc rotation" of the developing midgut is a fallacy of schematic drawings. Primary, secondary and tertiary loops arise in a hierarchical fashion. The predictable position and growth of secondary loops is pre-patterned and determines adult intestinal topography. We hypothesize based on published accounts that malrotations result from stunted development of secondary loops.

Role of host xanthine oxidase in infection due to enteropathogenic and Shiga-toxigenic Escherichia coli.

PubMed

Crane, John K; Naeher, Tonniele M; Broome, Jacqueline E; Boedeker, Edgar C

2013-04-01

Xanthine oxidase (XO), also known as xanthine oxidoreductase, has long been considered an important host defense molecule in the intestine and in breastfed infants. Here, we present evidence that XO is released from and active in intestinal tissues and fluids in response to infection with enteropathogenic Escherichia coli (EPEC) and Shiga-toxigenic E. coli (STEC), also known as enterohemorrhagic E. coli (EHEC). XO is released into intestinal fluids in EPEC and STEC infection in a rabbit animal model. XO activity results in the generation of surprisingly high concentrations of uric acid in both cultured cell and animal models of infection. Hydrogen peroxide (H(2)O(2)) generated by XO activity triggered a chloride secretory response in intestinal cell monolayers within minutes but decreased transepithelial electrical resistance at 6 to 22 h. H(2)O(2) generated by XO activity was effective at killing laboratory strains of E. coli, commensal microbiotas, and anaerobes, but wild-type EPEC and STEC strains were 100 to 1,000 times more resistant to killing or growth inhibition by this pathway. Instead of killing pathogenic bacteria, physiologic concentrations of XO increased virulence by inducing the production of Shiga toxins from STEC strains. In vivo, exogenous XO plus the substrate hypoxanthine did not protect and instead worsened the outcome of STEC infection in the rabbit ligated intestinal loop model of infection. XO released during EPEC and STEC infection may serve as a virulence-inducing signal to the pathogen and not solely as a protective host defense.

Ultrasonographic features of intestinal entrapment in dogs.

PubMed

Swift, Inar

2009-01-01

The clinical and ultrasonographic features of postoperative intestinal entrapment were assessed in five dogs. Four had vomiting and lethargy, and one had peracute collapse and hematochezia. Ultrasonographic findings in four of five dogs were similar, being characterized by focally hyperechoic mesentery and abdominal effusion, surrounding a single loop of amotile and dilated intestine. In some dogs, the affected intestinal loop had a thickened or corrugated wall, or alteration of wall layering. In one dog, the site of entrapment could be directly visualized. In the most severely affected dog, a large volume of echogenic peritoneal effusion was present, as well as fluid dilation of multiple intestinal loops. The ultrasonographic appearance of intestinal entrapment is similar to that of intestinal perforation or infarction by other causes.

Bovine Intestinal Alkaline Phosphatase Reduces Inflammation After Induction of Acute Myocardial Infarction in Mice.

PubMed

Fiechter, Danielle; Kats, Suzanne; Brands, Ruud; van Middelaar, Ben; Pasterkamp, Gerard; de Kleijn, Dominique; Seinen, Willem

2011-10-01

There has been increasing evidence suggesting that lipopolysaccharide or endotoxin may be an important activator of the innate immune system after acute myocardial infarction. Bovine intestinal alkaline phosphatase reduces inflammation in several endotoxin mediated diseases by dephosphorylation of the lipid A moiety of lipopolysaccharide. The aim of this study was to investigate the effect of bovine intestinal alkaline phosphatase on reducing inflammation after acute myocardial infarction. Just before permanent ligation of the left anterior descending coronary (LAD) artery to induce acute myocardial infarction in Balb/c mice, bovine intestinal alkaline phosphatase (bIAP) was administrated intravenously. After 4 hours, mice were sacrificed and the inflammatory response was assessed. Acute myocardial infarction induced the production of different cytokines, which were measured in blood. Treatment with bovine intestinal alkaline phosphatase resulted in a significant reduction of the pro-inflammatory cytokines IL-6, IL-1β and the chymase mouse mast cell protease-1. No difference in the production of the anti-inflammatory cytokine IL-10 was observed between the control group and the bovine intestinal alkaline phosphatase treated group. In a mouse model of permanent LAD coronary artery ligation, bIAP diminishes the pro-inflammatory responses but does not have an effect on the anti-inflammatory response in the acute phase after acute myocardial infarction.

BMP signaling controls buckling forces to modulate looping morphogenesis of the gut.

PubMed

Nerurkar, Nandan L; Mahadevan, L; Tabin, Clifford J

2017-02-28

Looping of the initially straight embryonic gut tube is an essential aspect of intestinal morphogenesis, permitting proper placement of the lengthy small intestine within the confines of the body cavity. The formation of intestinal loops is highly stereotyped within a given species and results from differential-growth-driven mechanical buckling of the gut tube as it elongates against the constraint of a thin, elastic membranous tissue, the dorsal mesentery. Although the physics of this process has been studied, the underlying biology has not. Here, we show that BMP signaling plays a critical role in looping morphogenesis of the avian small intestine. We first exploited differences between chicken and zebra finch gut morphology to identify the BMP pathway as a promising candidate to regulate differential growth in the gut. Next, focusing on the developing chick small intestine, we determined that Bmp2 expressed in the dorsal mesentery establishes differential elongation rates between the gut tube and mesentery, thereby regulating the compressive forces that buckle the gut tube into loops. Consequently, the number and tightness of loops in the chick small intestine can be increased or decreased directly by modulation of BMP activity in the small intestine. In addition to providing insight into the molecular mechanisms underlying intestinal development, our findings provide an example of how biochemical signals act on tissue-level mechanics to drive organogenesis, and suggest a possible mechanism by which they can be modulated to achieve distinct morphologies through evolution.

BMP signaling controls buckling forces to modulate looping morphogenesis of the gut

PubMed Central

Nerurkar, Nandan L.; Mahadevan, L.; Tabin, Clifford J.

2017-01-01

Looping of the initially straight embryonic gut tube is an essential aspect of intestinal morphogenesis, permitting proper placement of the lengthy small intestine within the confines of the body cavity. The formation of intestinal loops is highly stereotyped within a given species and results from differential-growth–driven mechanical buckling of the gut tube as it elongates against the constraint of a thin, elastic membranous tissue, the dorsal mesentery. Although the physics of this process has been studied, the underlying biology has not. Here, we show that BMP signaling plays a critical role in looping morphogenesis of the avian small intestine. We first exploited differences between chicken and zebra finch gut morphology to identify the BMP pathway as a promising candidate to regulate differential growth in the gut. Next, focusing on the developing chick small intestine, we determined that Bmp2 expressed in the dorsal mesentery establishes differential elongation rates between the gut tube and mesentery, thereby regulating the compressive forces that buckle the gut tube into loops. Consequently, the number and tightness of loops in the chick small intestine can be increased or decreased directly by modulation of BMP activity in the small intestine. In addition to providing insight into the molecular mechanisms underlying intestinal development, our findings provide an example of how biochemical signals act on tissue-level mechanics to drive organogenesis, and suggest a possible mechanism by which they can be modulated to achieve distinct morphologies through evolution. PMID:28193855

Bovine Intestinal Alkaline Phosphatase Reduces Inflammation After Induction of Acute Myocardial Infarction in Mice

PubMed Central

Fiechter, Danielle; Kats, Suzanne; Brands, Ruud; van Middelaar, Ben; Pasterkamp, Gerard; de Kleijn, Dominique; Seinen, Willem

2011-01-01

Background There has been increasing evidence suggesting that lipopolysaccharide or endotoxin may be an important activator of the innate immune system after acute myocardial infarction. Bovine intestinal alkaline phosphatase reduces inflammation in several endotoxin mediated diseases by dephosphorylation of the lipid A moiety of lipopolysaccharide. The aim of this study was to investigate the effect of bovine intestinal alkaline phosphatase on reducing inflammation after acute myocardial infarction. Methods Just before permanent ligation of the left anterior descending coronary (LAD) artery to induce acute myocardial infarction in Balb/c mice, bovine intestinal alkaline phosphatase (bIAP) was administrated intravenously. After 4 hours, mice were sacrificed and the inflammatory response was assessed. Acute myocardial infarction induced the production of different cytokines, which were measured in blood. Results Treatment with bovine intestinal alkaline phosphatase resulted in a significant reduction of the pro-inflammatory cytokines IL-6, IL-1β and the chymase mouse mast cell protease-1. No difference in the production of the anti-inflammatory cytokine IL-10 was observed between the control group and the bovine intestinal alkaline phosphatase treated group. Conclusion In a mouse model of permanent LAD coronary artery ligation, bIAP diminishes the pro-inflammatory responses but does not have an effect on the anti-inflammatory response in the acute phase after acute myocardial infarction. PMID:28357012

Imipenem and normal saline with cyclophosphamide have positive effects on the intestinal barrier in rats with sepsis.

PubMed

Yang, Junting; Zhang, Shunwen; Wu, Jiangdong; Zhang, Jie; Dong, Jiangtao; Guo, Peng; Tang, Suyu; Zhang, Wanjiang; Wu, Fang

2018-06-12

Sepsis is a life-threatening organ dysfunction caused the dysregulation of host inflammatory response and immunosuppression to infection Early recognition and intervention are hence of paramount importance. In this respect the "sepsis bundle" was proposed in 2004 to be instituted in cases of suspected sepsis. We hypothesised that a combination treatment of the sepsis bundle with cyclophosphamide would improve the function of the intestinal mucosa and enhance survival in rats with induced sepsis. Sprague-Dawley rats were divided into 5 different groups: sham, cecal ligation and puncture (CLP), cyclophosphamide (CTX), imipenem+normal saline (NS) and imipenem+NS+CTX. Cecal ligation and puncture were used for inducing the polymicrobial sepsis. Western-blot was used to measure the occludin protein, and ELISA for examining the plasma level of cytokines IL-6, IL-10 and TNF-α. TUNEL assay for testing the intestinal mucosal apoptosis, and hematoxylin-eosin staining for observing the intestinal mucosal changes. The permeability of intestinal mucosa was determined by the plasma level of FD-70. The results showed that the combination treatment of the sepsis bundle with cyclophosphamide attenuated cytokine levels, inhibited epithelial cell apoptosis and improved the function of the intestinal barrier. The survival rate of the group treated with the combined therapy was significantly higher than that of the other groups. The combination treatment of sepsis bundle with cyclophosphamide improves the function of the intestinal barrier and enhances survival in septic rats.

Firewalls Prevent Systemic Dissemination of Vectors Derived from Human Adenovirus Type 5 and Suppress Production of Transgene-Encoded Antigen in a Murine Model of Oral Vaccination

PubMed Central

Revaud, Julien; Unterfinger, Yves; Rol, Nicolas; Suleman, Muhammad; Shaw, Julia; Galea, Sandra; Gavard, Françoise; Lacour, Sandrine A.; Coulpier, Muriel; Versillé, Nicolas; Havenga, Menzo; Klonjkowski, Bernard; Zanella, Gina; Biacchesi, Stéphane; Cordonnier, Nathalie; Corthésy, Blaise; Ben Arous, Juliette; Richardson, Jennifer P.

2018-01-01

To define the bottlenecks that restrict antigen expression after oral administration of viral-vectored vaccines, we tracked vectors derived from the human adenovirus type 5 at whole body, tissue, and cellular scales throughout the digestive tract in a murine model of oral delivery. After intragastric administration of vectors encoding firefly luciferase or a model antigen, detectable levels of transgene-encoded protein or mRNA were confined to the intestine, and restricted to delimited anatomical zones. Expression of luciferase in the form of multiple small bioluminescent foci in the distal ileum, cecum, and proximal colon suggested multiple crossing points. Many foci were unassociated with visible Peyer's patches, implying that transduced cells lay in proximity to villous rather than follicle-associated epithelium, as supported by detection of transgene-encoded antigen in villous epithelial cells. Transgene-encoded mRNA but not protein was readily detected in Peyer's patches, suggesting that post-transcriptional regulation of viral gene expression might limit expression of transgene-encoded antigen in this tissue. To characterize the pathways by which the vector crossed the intestinal epithelium and encountered sentinel cells, a fluorescent-labeled vector was administered to mice by the intragastric route or inoculated into ligated intestinal loops comprising a Peyer's patch. The vector adhered selectively to microfold cells in the follicle-associated epithelium, and, after translocation to the subepithelial dome region, was captured by phagocytes that expressed CD11c and lysozyme. In conclusion, although a large number of crossing events took place throughout the intestine within and without Peyer's patches, multiple firewalls prevented systemic dissemination of vector and suppressed production of transgene-encoded protein in Peyer's patches. PMID:29423380

Down-regulation of intestinal epithelial innate response by probiotic yeasts isolated from kefir.

PubMed

Romanin, David; Serradell, María; González Maciel, Dolores; Lausada, Natalia; Garrote, Graciela L; Rumbo, Martín

2010-06-15

Kefir is obtained by milk fermentation with a complex microbial population included in a matrix of polysaccharide and proteins. Several health-promoting activities has been attributed to kefir consumption. The aim of this study was to select microorganisms from kefir able to down-regulate intestinal epithelial innate response and further characterize this activity. Caco-2 cells stably transfected with a human CCL20 promoter luciferase reporter were used to screen a collection of 24 yeast and 23 bacterial strains isolated from kefir. The Toll-like receptor 5 agonist, flagellin was used to activate the reporter cells, while pre-incubation with the selected strains was tested to identify strains with the capacity to inhibit cell activation. In this system, 21 yeast strains from the genera Saccharomyces, Kluyveromyces and Issatchenkia inhibited almost 100% of the flagellin-dependent activation, whereas only some lactobacilli strains showed a partial effect. K. marxianus CIDCA 8154 was selected for further characterization. Inhibitory activity was confirmed at transcriptional level on Caco-2/TC-7 and HT-29 cells upon flagellin stimulation. A similar effect was observed using other pro-inflammatory stimulation such as IL-1beta and TNF-alpha. Pre-incubation with yeasts induced a down-regulation of NF-kappaB signalling in epithelial cells in vitro, as well as expression of other pro-inflammatory chemokines such as CXCL8 and CXCL2. Furthermore, modulation of CCL20 mRNA expression upon flagellin stimulation was evidenced in vivo, in a mouse ligated intestinal loop model. Results indicate kefir contains microorganisms able to abolish the intestinal epithelial inflammatory response that could explain some of the properties attributed to this fermented milk. Copyright 2010 Elsevier B.V. All rights reserved.

A cytotoxic haemolysin from Treponema hyodysenteriae--a probable virulence determinant in swine dysentery.

PubMed

Lysons, R J; Kent, K A; Bland, A P; Sellwood, R; Robinson, W F; Frost, A J

1991-02-01

The haemolysin from a virulent strain of Treponema hyodysenteriae was extracted and injected into ligated loops of the ileum and colon of germ-free pigs. It caused severe epithelial damage, especially to the differentiated cells at the tips of the villi in the ileum and the cells in the intercrypt zones of the colon; goblet cells were less affected. The changes in the colon were similar to those seen in natural cases of swine dysentery. The ligated loop offers a means of investigating pathogenic mechanisms and the mode of action of the toxin. This study demonstrated that the haemolysin was a potent cytotoxin for pig enterocytes, and a probable virulence determinant in swine dysentery.

Label-free fluorescence strategy for sensitive detection of adenosine triphosphate using a loop DNA probe with low background noise.

PubMed

Lin, Chunshui; Cai, Zhixiong; Wang, Yiru; Zhu, Zhi; Yang, Chaoyong James; Chen, Xi

2014-07-15

A simple, rapid, label-free, and ultrasensitive fluorescence strategy for adenosine triphosphate (ATP) detection was developed using a loop DNA probe with low background noise. In this strategy, a loop DNA probe, which is the substrate for both ligation and digestion enzyme reaction, was designed. SYBR green I (SG I), a double-stranded specific dye, was applied for the readout fluorescence signal. Exonuclease I (Exo I) and exonuclease III (Exo III), sequence-independent nucleases, were selected to digest the loop DNA probe in order to minimize the background fluorescence signal. As a result, in the absence of ATP, the loop DNA was completely digested by Exo I and Exo III, leading to low background fluorescence owing to the weak electrostatic interaction between SG I and mononucleotides. On the other hand, ATP induced the ligation of the nicking site, and the sealed loop DNA resisted the digestion of Exo I and ExoIII, resulting in a remarkable increase of fluorescence response. Upon background noise reduction, the sensitivity of the ATP determination was improved significantly, and the detection limitation was found to be 1.2 pM, which is much lower than that in almost all the previously reported methods. This strategy has promise for wide application in the determination of ATP.

S007--Preliminary Evaluation of the Pattern Cutting and the Ligating Loop Virtual Laparoscopic Trainers

PubMed Central

Chellali, A.; Ahn, W.; Sankaranarayanan, G.; Flinn, J. T.; Schwaitzberg, S. D.; Jones, D.B.; De, Suvranu; Cao, C.G.L.

2014-01-01

Introduction The Fundamentals of Laparoscopic Surgery (FLS) trainer is currently the standard for training and evaluating basic laparoscopic skills. However, its manual scoring system is time-consuming and subjective. The Virtual Basic Laparoscopic Skill Trainer (VBLaST©) is the virtual version of the FLS trainer which allows automatic and real time assessment of skill performance, as well as force feedback. In this study, the VBLaST© pattern cutting (VBLaST-PC©) and ligating loop (VBLaST-LL©) tasks were evaluated as part of a validation study. We hypothesized that performance would be similar on the FLS and VBLaST© trainers, and that subjects with more experience would perform better than those with less experience on both trainers. Methods Fifty-five subjects with varying surgical experience were recruited at the Learning Center during the 2013 SAGES annual meeting and were divided into two groups: experts (PGY 5, surgical fellows and surgical attendings) and novices (PGY 1–4). They were asked to perform the pattern cutting or the ligating loop task on the FLS and the VBLaST© trainers. Their performance scores for each trainer were calculated and compared. Results There were no significant differences between the FLS and VBLaST© scores for either the pattern cutting or the ligating loop task. Experts’ scores were significantly higher than the scores for novices on both trainers. Conclusion This study showed that the subjects’ performance on the VBLaST© trainer was similar to the FLS performance for both tasks. Both the VBLaST-PC© and the VBLaST-LL© tasks permitted discrimination between the novice and expert groups. Though concurrent and discriminant validity has been established, further studies to establish convergent and predictive validity are needed. Once validated as a training system for laparoscopic skills, the system is expected to overcome the current limitations of the FLS trainer. PMID:25159626

Increased immunostimulatory activity of polypod-like structured DNA by ligation of the terminal loop structures.

PubMed

Mohri, Kohta; Takahashi, Natsuki; Nishikawa, Makiya; Kusuki, Eri; Shiomi, Tomoki; Takahashi, Yuki; Takakura, Yoshinobu

2012-11-10

The immunostimulatory activity of phosphodiester DNA containing unmethylated cytosine-guanine (CpG) dinucleotides can be increased by converting it into branched structures. These structures could be stabilized by ligating the 5'- and 3'-ends to form a closed loop with no terminal ends. To further increase the ability of branched DNA assemblies to induce cytokines, a series of tetrapod-like structured DNA, or tetrapodna, were designed using four 48-base oligodeoxynucleotides (ODNs). All these preparations were designed to have the same sequence except for the nick sites, and all the ODNs of one of the tetrapodna preparations were ligated to obtain circular tetrapodna. The nick site significantly influenced the formation of the structure and melting temperature (Tm), but hardly affected the enzymatic stability of the tetrapodna preparations. Circular tetrapodna exhibited a significantly higher Tm and was more stable in mouse serum than its non-ligated counterparts. The amounts of cytokines released from macrophage-like RAW264.7 cells or dendritic DC2.4 cells after addition of circular tetrapodna were not significantly higher than those after addition of other tetrapodna preparations under conditions when no serum was present. However, when serum was present, circular tetrapodna induced the greatest amount of tumor necrosis factor-α, indicating that circular tetrapodna is effective in inducing cytokines under conditions where DNA-degrading enzymes are present. The cellular association of tetrapodna preparations was almost unaffected by ligation of the terminal ends. These results indicate that circular tetrapodna with no terminal ends is more effective than its non-ligated counterparts in the presence of serum. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of surface chemistry on nanoparticle interaction with gastrointestinal mucus and distribution in the gastrointestinal tract following oral and rectal administration in the mouse.

PubMed

Maisel, Katharina; Ensign, Laura; Reddy, Mihika; Cone, Richard; Hanes, Justin

2015-01-10

It is believed that mucoadhesive surface properties on particles delivered to the gastrointestinal (GI) tract improve oral absorption or local targeting of various difficult-to-deliver drug classes. To test the effect of nanoparticle mucoadhesion on distribution of nanoparticles in the GI tract, we orally and rectally administered nano- and microparticles that we confirmed possessed surfaces that were either strongly mucoadhesive or non-mucoadhesive. We found that mucoadhesive particles (MAP) aggregated in mucus in the center of the GI lumen, far away from the absorptive epithelium, both in healthy mice and in a mouse model of ulcerative colitis (UC). In striking contrast, water absorption by the GI tract rapidly and uniformly transported non-mucoadhesive mucus-penetrating particles (MPP) to epithelial surfaces, including reaching the surfaces between villi in the small intestine. When using high gavage fluid volumes or injection into ligated intestinal loops, common methods for assessing oral drug and nanoparticle absorption, we found that both MAP and MPP became well-distributed throughout the intestine, indicating that the barrier properties of GI mucus were compromised. In the mouse colorectum, MPP penetrated into mucus in the deeply in-folded surfaces to evenly coat the entire epithelial surface. Moreover, in a mouse model of UC, MPP were transported preferentially into the disrupted, ulcerated tissue. Our results suggest that delivering drugs in non-mucoadhesive MPP is likely to provide enhanced particle distribution, and thus drug delivery, in the GI tract, including to ulcerated tissues. Copyright © 2014 Elsevier B.V. All rights reserved.

High-throughput determination of RNA structure by proximity ligation.

PubMed

Ramani, Vijay; Qiu, Ruolan; Shendure, Jay

2015-09-01

We present an unbiased method to globally resolve RNA structures through pairwise contact measurements between interacting regions. RNA proximity ligation (RPL) uses proximity ligation of native RNA followed by deep sequencing to yield chimeric reads with ligation junctions in the vicinity of structurally proximate bases. We apply RPL in both baker's yeast (Saccharomyces cerevisiae) and human cells and generate contact probability maps for ribosomal and other abundant RNAs, including yeast snoRNAs, the RNA subunit of the signal recognition particle and the yeast U2 spliceosomal RNA homolog. RPL measurements correlate with established secondary structures for these RNA molecules, including stem-loop structures and long-range pseudoknots. We anticipate that RPL will complement the current repertoire of computational and experimental approaches in enabling the high-throughput determination of secondary and tertiary RNA structures.

Effect of Zinc in Enteropathogenic Escherichia coli Infection▿ †

PubMed Central

Crane, John K.; Naeher, Tonniele M.; Shulgina, Irina; Zhu, Chengru; Boedeker, Edgar C.

2007-01-01

Enteropathogenic Escherichia coli (EPEC) infection triggers the release of ATP from host intestinal cells, and the ATP is broken down to ADP, AMP, and adenosine in the lumen of the intestine. Ecto-5′-nucleotidase (CD73) is the main enzyme responsible for the conversion of 5′-AMP to adenosine, which triggers fluid secretion from host intestinal cells and also has growth-promoting effects on EPEC bacteria. In a recent study, we examined the role of the host enzyme CD73 in EPEC infection by testing the effect of ecto-5′-nucleotidase inhibitors. Zinc was a less potent inhibitor of ecto-5′-nucleotidase in vitro than the nucleotide analog α,β-methylene-ADP, but in vivo, zinc was much more efficacious in preventing EPEC-induced fluid secretion in rabbit ileal loops than α,β-methylene-ADP. This discrepancy between the in vitro and in vivo potencies of the two inhibitors prompted us to search for potential targets of zinc other than ecto-5′-nucleotidase. Zinc, at concentrations that produced little or no inhibition of EPEC growth, caused a decrease in the expression of EPEC protein virulence factors, such as bundle-forming pilus (BFP), EPEC secreted protein A, and other EPEC secreted proteins, and reduced EPEC adherence to cells in tissue culture. The effects of zinc were not mimicked by other transition metals, such as manganese, iron, copper, or nickel, and the effects were not reversed by an excess of iron. Quantitative real-time PCR showed that zinc reduced the abundance of the RNAs encoded by the bfp gene, by the plasmid-encoded regulator (per) gene, by the locus for the enterocyte effacement (LEE)-encoded regulator (ler) gene, and by several of the esp genes. In vivo, zinc reduced EPEC-induced fluid secretion into ligated rabbit ileal loops, decreased the adherence of EPEC to rabbit ileum, and reduced histopathological damage such as villus blunting. Some of the beneficial effects of zinc on EPEC infection appear to be due to the action of the metal on EPEC bacteria as well as on the host. PMID:17875638

Does pharmaconutrition with L-arginine and/or alpha-tocopherol improve the gut barrier in bile duct ligated rats?

PubMed

Tuncyurek, P; Sari, M; Firat, O; Mutaf, I; Gulter, C; Tunger, A; Yuce, G; Yilmaz, M; Makay, O; Dayangac, M; Ersin, S

2006-01-01

Nitric oxide supplementation and antioxidant therapy modulate gut barrier function, but the relationships between enhanced nitric oxide production, antioxidant administration, and biliary obstruction remain unclear. We evaluated the role of nitric oxide and alpha-tocopherol supplementation in bile duct ligated rats. Fifty male Wistar albino rats underwent sham operation (group I; control animals) or bile duct ligation (groups II, III, IV, and V). The ligation groups received the following regimens: standard pellet diet (group II), pellet diet plus intramuscularly administered alpha-tocopherol (group III), and L-arginine-enriched pellet diet without (group IV) or with (group V) alpha-tocopherol. Nitric oxide, malondialdehyde, and alpha-tocopherol concentrations were assessed at the end of 3 weeks. Liver and intestinal samples were scored histologically. Mesenteric lymph node and liver cultures were assessed for bacterial translocation. The liver malondialdehyde concentration was highest in group III. The nitric oxide content in the liver was higher in groups III and V, as were the blood alpha-tocopherol levels. Bacterial translocation was evident following bile duct ligation, but did not differ among the treatment groups. Intestinal histology revealed that group III had the lowest villus height, that group V had the least villus count, and that group II had the highest mucous cell count. The fibrosis scores were higher in groups IV and V. An obvious effect of alpha-tocopherol (with or without L-arginine) on the gut barrier could not be demonstrated. Moreover, the L-arginine-enriched diet promoted fibrosis in the liver. Thus, while biliary duct obstruction triggers bacterial translocation, nitric oxide and/or alpha-tocopherol supplementation did not seem to improve the gut barrier in our model. Copyright 2006 S. Karger AG, Basel.

Sonographic diagnosis of fetal intestinal volvulus with ileal atresia: a case report.

PubMed

Yu, Wang; Ailu, Cai; Bing, Wang

2013-05-01

Fetal intestinal volvulus is a rare life-threatening condition usually manifesting after birth with most cases being associated with intestinal malrotation. It appears on prenatal sonography (US) as a twisting of the bowel loops around the mesenteric artery, leading to mechanical obstruction and ischemic necrosis of the bowel. We report a case of intrauterine intestinal volvulus with ileal atresia, suspected when US revealed a typical "whirlpool" sign at 37 weeks' gestation, with a segment of markedly distended bowel loops and small amount of fetal ascites. Copyright © 2012 Wiley Periodicals, Inc.

5C-ID: Increased resolution Chromosome-Conformation-Capture-Carbon-Copy with in situ 3C and double alternating primer design.

PubMed

Kim, Ji Hun; Titus, Katelyn R; Gong, Wanfeng; Beagan, Jonathan A; Cao, Zhendong; Phillips-Cremins, Jennifer E

2018-05-14

Mammalian genomes are folded in a hierarchy of compartments, topologically associating domains (TADs), subTADs, and looping interactions. Currently, there is a great need to evaluate the link between chromatin topology and genome function across many biological conditions and genetic perturbations. Hi-C can generate genome-wide maps of looping interactions but is intractable for high-throughput comparison of loops across multiple conditions due to the enormous number of reads (>6 Billion) required per library. Here, we describe 5C-ID, a new version of Chromosome-Conformation-Capture-Carbon-Copy (5C) with restriction digest and ligation performed in the nucleus (in situ Chromosome-Conformation-Capture (3C)) and ligation-mediated amplification performed with a double alternating primer design. We demonstrate that 5C-ID produces higher-resolution 3D genome folding maps with reduced spatial noise using markedly lower cell numbers than canonical 5C. 5C-ID enables the creation of high-resolution, high-coverage maps of chromatin loops in up to a 30 Megabase subset of the genome at a fraction of the cost of Hi-C. Copyright © 2018 Elsevier Inc. All rights reserved.

INTESTINAL OBSTRUCTION

PubMed Central

Whipple, G. H.; Stone, H. B.; Bernheim, B. M.

1913-01-01

Closed duodenal loops may be made in dogs by ligatures placed just below the pancreatic duct and just beyond the duodenojejunal junction, together with a posterior gastro-enterostomy. These closed duodenal loop dogs die with symptoms like those of patients suffering from volvulus or high intestinal obstruction. This duodenal loop may simulate closely a volvulus in which there has been no vascular disturbance. Dogs with closed duodenal loops which have been washed out carefully survive a little longer on the average than animals with unwashed loops. The duration of life in the first instance is one to three days, with an average of about forty-eight hours. The dogs usually lose considerable fluid by vomiting and diarrhea. A weak pulse, low blood pressure and temperature are usually conspicuous in the last stages. Autopsy shows more or less splanchnic congestion which may be most marked in the mucosa of the upper small intestine. The peritoneum is usually clear and the closed loop may be distended with thin fluid, or collapsed, and contain only a small amount of pasty brown material. The mucosa of the loop may show ulceration and even perforation, but in the majority of cases it is intact and exhibits only a moderate congestion. Simple intestinal obstruction added to a closed duodenal loop does not modify the result in any manner, but it may hasten the fatal outcome. The liver plays no essential role as a protective agent against this poison, for a dog with an Eck fistula may live three days with a closed loop. A normal dog reacts to intraportal injection and to intravenous injection of the toxic substance in an identical manner. Drainage of this loop under certain conditions may not interfere with the general health over a period of weeks or months. Excision of the part of the duodenum included in this loop causes no disturbance. The material from the closed duodenal loops contains no bile, pancreatic juice, gastric juice, or split products from the food. It can be formed in no other way than by the activity of the intestinal mucosa and the growth of the intestinal bacteria. This material after dilution, autolysis, sterilization, and filtration produces a characteristic effect when introduced intravenously. When in toxic doses it causes a profound drop in blood pressure, general collapse, drop in temperature, salivation, vomiting, and profuse diarrhea, which is often blood-stained. Splanchnic congestion is the conspicuous feature at autopsy and shows especially in the villi of the duodenal and jejunal mucosæ. Adrenalin, during this period of low blood pressure and splanchnic congestion, will cause the usual reaction when given intravenously, but applied locally or given intravenously it causes no bleaching of the engorged intestinal mucosa. Secretin is not found in the duodenal loop fluid, and the loop material does not influence the pancreatic secretion. Intraportal injection of the toxic material gives a reaction similar to intravenous injection. Intraperitoneal and subcutaneous injections produce a relatively slow reaction which closely resembles the picture seen in the closed duodenal loop dog. In both cases there is a relatively slow absorption, but the splanchnic congestion and other findings, though less intense, are present in both groups. There seems, therefore, to be no escape from the conclusion that a poisonous substance is formed in this closed duodenal loop which is absorbed from it and causes intoxication and death. Injection of this toxic substance into a normal dog gives intoxication and a reaction more intense but similar to that developing in a closed-loop dog. PMID:19867644

Rare small intestinal volvulus from entrapment in hepato-diaphragmatic adhesions in a 45-year-old lady

PubMed Central

Olaoye, Iyiade Olatunde; Adesina, Micheal Dapo

2016-01-01

Small intestinal volvulus is rare in adults and rarely caused by string adhesions between the liver and the diaphragm. Similar adhesions were described in Fitz-Hugh-Curtis syndrome. We report a 45-year-old lady with small intestinal volvulus from entrapment of a loop in string adhesions between the liver and the diaphragm. Her plain radiographs showed a significant shadow of the trapped loop. PMID:28003317

Cranberry extract inhibits in vitro adhesion of F4 and F18+Escherichia coli to pig intestinal epithelium and reduces in vivo excretion of pigs orally challenged with F18+ verotoxigenic E. coli.

PubMed

Coddens, Annelies; Loos, Michaela; Vanrompay, Daisy; Remon, Jean Paul; Cox, Eric

2017-04-01

F4 + E. coli and F18 + E. coli infections are an important threat for pig industry worldwide. Antibiotics are commonly used to treat infected piglets, but the emerging development of resistance against antibiotics raises major concerns. Hence, alternative therapies to prevent pigs from F4 + E. coli and F18 + E. coli infections need to be developed. Since cranberry previously showed anti-adhesive activity against uropathogenic E. coli, we aimed to investigate whether cranberry extract could also inhibit binding of F4 + E. coli and F18 + E. coli to pig intestinal epithelium. Using the in vitro villus adhesion assay, we found that low concentrations of cranberry extract (20μg or 100μg/ml) have strong inhibitory activity on F4 + E. coli (75.3%, S.D.=9.31 or 95.8%, S.D.=2.56, respectively) and F18 + E. coli adherence (100% inhibition). This effect was not due to antimicrobial activity. Moreover, cranberry extract (10mg or 100mg) could also abolish in vivo binding of F4 and F18 fimbriae to the pig intestinal epithelium in ligated loop experiments. Finally, two challenge experiments with F18 + E. coli were performed to address the efficacy of in-feed or water supplemented cranberry extract. No effect could be observed in piglets that received cranberry extract only in feed (1g/kg or 10g/kg). However, supplementation of feed (10g/kg) and drinking water (1g/L) significantly decreased excretion and diarrhea. The decreased infection resulted in a decreased serum antibody response indicating reduced exposure to F18 + E. coli. Copyright © 2017 Elsevier B.V. All rights reserved.

A simplified technique for a totally diverting transverse loop colostomy and distal irrigation.

PubMed

Rose, D; Koniges, F; Frazier, T G

1985-12-01

This technique of totally diverting loop colostomy may be performed as an independent procedure or with exploratory laparotomy and surgical treatment on the distal part of the colon. Either a transverse or sigmoid loop colostomy can be used for diversion without the risk of fecal contamination of the peritoneal cavity, particularly when working with unprepared intestine. When distal irrigation is desired to purge the intestine of fecal material, either intraoperatively or as part of a subsequent intestinal preparation, it can easily be accomplished by placing an irrigating catheter distal to the staple line. In addition, the use of a small rubber suspension bar facilitates application of standard colostomy appliances for the stoma.

Systems Biology Analysis of Gene Expression during In Vivo Mycobacterium avium paratuberculosis Enteric Colonization Reveals Role for Immune Tolerance

PubMed Central

Khare, Sangeeta; Lawhon, Sara D.; Drake, Kenneth L.; Nunes, Jairo E. S.; Figueiredo, Josely F.; Rossetti, Carlos A.; Gull, Tamara; Everts, Robin E.; Lewin, Harris A.; Galindo, Cristi L.; Garner, Harold R.; Adams, Leslie Garry

2012-01-01

Survival and persistence of Mycobacterium avium subsp. paratuberculosis (MAP) in the intestinal mucosa is associated with host immune tolerance. However, the initial events during MAP interaction with its host that lead to pathogen survival, granulomatous inflammation, and clinical disease progression are poorly defined. We hypothesize that immune tolerance is initiated upon initial contact of MAP with the intestinal Peyer's patch. To test our hypothesis, ligated ileal loops in neonatal calves were infected with MAP. Intestinal tissue RNAs were collected (0.5, 1, 2, 4, 8 and 12 hrs post-infection), processed, and hybridized to bovine gene expression microarrays. By comparing the gene transcription responses of calves infected with the MAP, informative complex patterns of expression were clearly visible. To interpret these complex data, changes in the gene expression were further analyzed by dynamic Bayesian analysis, and genes were grouped into the specific pathways and gene ontology categories to create a holistic model. This model revealed three different phases of responses: i) early (30 min and 1 hr post-infection), ii) intermediate (2, 4 and 8 hrs post-infection), and iii) late (12 hrs post-infection). We describe here the data that include expression profiles for perturbed pathways, as well as, mechanistic genes (genes predicted to have regulatory influence) that are associated with immune tolerance. In the Early Phase of MAP infection, multiple pathways were initiated in response to MAP invasion via receptor mediated endocytosis and changes in intestinal permeability. During the Intermediate Phase, perturbed pathways involved the inflammatory responses, cytokine-cytokine receptor interaction, and cell-cell signaling. During the Late Phase of infection, gene responses associated with immune tolerance were initiated at the level of T-cell signaling. Our study provides evidence that MAP infection resulted in differentially regulated genes, perturbed pathways and specifically modified mechanistic genes contributing to the colonization of Peyer's patch. PMID:22912686

Poly(vinyl methyl ether/maleic anhydride)-Doped PEG-PLA Nanoparticles for Oral Paclitaxel Delivery To Improve Bioadhesive Efficiency.

PubMed

Wang, Qian; Li, Chan; Ren, Tianyang; Chen, Shizhu; Ye, Xiaoxia; Guo, Hongbo; He, Haibing; Zhang, Yu; Yin, Tian; Liang, Xing-Jie; Tang, Xing

2017-10-02

Bioadhesive nanoparticles based on poly(vinyl methyl ether/maleic anhydride) (PVMMA) and poly(ethylene glycol) methyl ether-b-poly(d,l-lactic acid) (mPEG-b-PLA) were produced by the emulsification solvent evaporation method. Paclitaxel was utilized as the model drug, with an encapsulation efficiency of up to 90.2 ± 4.0%. The nanoparticles were uniform and spherical in shape and exhibited a sustained drug release compared with Taxol. m-NPs also exhibited favorable bioadhesive efficiency at the same time. Coumarin 6 or DiR-loaded nanoparticles with/without PVMMA (C6-m-NPs/DiR-m-NPs or C6-p-NPs/DiR-p-NPs) were used for cellular uptake and intestinal adhesion experiments, respectively. C6-m-NPs were shown to enhance cellular uptake, and caveolae/lipid raft mediated endocytosis was the primary route for the uptake of the nanoparticles. Favorable bioadhesive efficiency led to prolonged retention in the intestine reflected by the fluorescence in isolated intestines ex vivo. In a ligated intestinal loops model, C6-m-NPs showed a clear advantage for transporting NPs across the mucus layer over C6-p-NPs and free C6. The apparent permeability coefficient (Papp) of PTX-m-NPs through Caco-2/HT29 monolayers was 1.3- and 1.6-fold higher than PTX-p-NPs and Taxol, respectively, which was consistent with the AUC 0-t of different PTX formulations after oral administration in rats. PTX-m-NPs also exhibited a more effective anticancer efficacy, with an IC 50 of 0.2 ± 1.4 μg/mL for A549 cell lines, further demonstrating the advantage of bioadhesive nanoparticles. The bioadhesive nanoparticles m-NPs demonstrated both mucus permeation and epithelial absorption, and thus, this bioadhesive drug delivery system has the potential to improve the bioavailability of drugs that are insoluble in the gastrointestinal environment.

Changes in extrathymic T cells in the liver and intestinal intraepithelium in mice with obstructive jaundice.

PubMed

Ueno, Kimihiko; Ajiki, Tetsuo; Watanabe, Hisami; Abo, Toru; Takeyama, Yoshifumi; Onoyama, Hirohiko; Kuroda, Yoshikazu

2004-03-01

Recently, T cells were classified into two categories: intrathymic T cells (ITCs; thymus-derived T cells) and extrathymic T cells (ETCs). ETC, localized in the liver and intestinal intraepithelium (IE), play an important immunologic role in the suppressed condition of T-cell development in the thymus. Given the fact that complications of surgery in patients with obstructive jaundice are often related to immunosuppression in the gut-liver circulation, we attempted to investigate the changes in the proportion of ETCs in mice with obstructive jaundice. Three mice models were prepared ( n = 10 per group): sham group with simple laparotomy; ligation group with common bile duct ligation; deoxycholic acid (DCA) group with an oral intake of DCA as a model of the presence of bile salts in the gut lumen. In each model, total mononuclear cells (MNCs), ITCs in the thymus, and ETCs in the liver and IE were counted using monoclonal antibodies in conjunction with a two-color immunofluorescence test by flow cytometry. In the ligation group the number of MNCs was reduced in the thymus and IE, and only those in the IE recovered after oral intake of DCA. A decrease of ITCs in the thymus and the increase in ETCs in the liver and IE occurred simultaneously during the early phase of biliary obstruction. At day 7 after biliary obstruction, ETCs in the livers of the DCA and ligation groups decreased to nearly the level in the sham group. However, on day 7 the ETCs in the IE remained significantly higher in the DCA group than in the ligation group. These results suggested that ETCs can act in place of ITCs at an early phase of obstructive jaundice, and the presence of bile in the gut lumen may be associated with the consumption of ETCs in the IE, a reaction that may bring about improved immunoreactivity.

Influence of prophylactic probiotics and selective decontamination on bacterial translocation in patients undergoing pancreatic surgery: a randomized controlled trial.

PubMed

Diepenhorst, Gwendolyn M P; van Ruler, Oddeke; Besselink, Marc G H; van Santvoort, Hjalmar C; Wijnandts, Paul R; Renooij, Willem; Gouma, Dirk J; Gooszen, Hein G; Boermeester, Marja A

2011-01-01

Bacterial translocation (BT) is suspected to play a major role in the development of infections in surgical patients. However, the clinical association between intestinal barrier dysfunction, BT, and septic morbidity has remained unconfirmed. The objective of this study was to study BT in patients undergoing major abdominal surgery and the effects of probiotics, selective decontamination of the digestive tract (SDD), and standard treatment on intestinal barrier function. In a randomized controlled setting, 30 consecutive patients planned for elective pylorus-preserving pancreaticoduodenectomy (PPPD) were allocated to receive perioperatively probiotics, SDD, or standard treatment. To assess intestinal barrier function, intestinal fatty acid-binding protein (mucosal damage) and polyethylene glycol recovery (intestinal permeability) in urine were measured perioperatively. BT was assessed by real-time polymerase chain reaction and multiplex ligation-dependent probe amplification (MLPA) in mesenteric lymph nodes (MLNs) harvested early (baseline control) and at the end of surgery ("end-of-surgery" MLNs, after 3h in PPPD patients). Polymerase chain reaction detected bacterial DNA in 18 of 27 end-of-surgery MLNs and in 13 of 23 control MLNs (P = 0.378). Probiotics and SDD had no significant effect on the number of positive MLNs or the change in bacterial DNA during operation. Multiplex ligation-dependent probe amplification analysis showed significantly increased expression of only 4 of 30 inflammatory mediator-related genes in end-of-surgery compared with early sampled MLN (P < 0.05). Polyethylene glycol recovery was unaffected by operation, probiotics and SDD as compared with standard treatment. Intestinal fatty acid-binding protein levels were increased shortly postoperatively only in patients treated with SDD (P = 0.02). Probiotics and SDD did not influence BT, intestinal permeability, or inflammatory mediator expression. Bacterial translocation after abdominal surgery may be part of normal antigen-sampling processes of the gut.

Down-regulation of NF-κB signaling by Gordonia bronchialis prevents the activation of gut epithelial cells.

PubMed

Smaldini, Paola L; Stanford, John; Romanin, David E; Fossati, Carlos A; Docena, Guillermo H

2014-08-01

The immunomodulatory power of heat-killed Gordonia bronchialis was studied on gut epithelial cells activated with pro-inflammatory stimuli (flagellin, TNF-α or IL-1β). Light emission of luciferase-transfected epithelial cells and mRNA expression of IL-1β, TNF-α, IL-6, CCL20, IL-8 and MCP-1 were measured. NF-κB activation was assessed by immunofluorescence and immunoblotting, and induction of reactive oxygen species (ROS) was evaluated. In vivo inhibitory properties of G. bronchialis were studied with ligated intestinal loop assay and in a mouse model of food allergy. G. bronchialis promoted the down-regulation of the expression of CCL20 and IL-1β on activated epithelial cells in a dose-dependent manner. A concomitant blocking of nuclear p65 translocation with increased production of ROS was found. In vivo experiments confirmed the inhibition of CCL20 expression and the suppression of IgE sensitization and hypersensitivity symptoms in the food allergy mouse model. In conclusion, heat-killed G. bronchialis inhibited the activation of NF-κB pathway in human epithelial cells, and suppressed the expression of CCL20. These results indicate that G. bronchialis may be used to modulate the initial steps of innate immune activation, which further suppress the allergic sensitization. This approach may be exploited as a therapy for intestinal inflammation. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Tolerance of canine anastomoses to intraoperative radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tepper, J.E.; Sindelar, W.; Travis, E.L.

1983-07-01

Radiation has been given intraoperatively to various abdominal structures in dogs, using a fixed horizontal 11 MeV electron beam at the Armed Forces Radiobiologic Research Institute. Animals were irradiated with single doses of 2000, 3000 and 4500 rad to a field which extended from the bifurcation of the aorta to the rib cage. All animals were irradiated during laparotomy under general anesthesia. Because the clinical use of intraoperative radiotherapy in cancer treatment will occasionally require irradiation of anastomosed large vessels and blind loops of bowel, the tolerance of aortic anastomoses and the suture lines of blind loops of jejunum tomore » irradiation were studied. Responses in these experiments were scored at times up to one year after irradiation. In separate experiments both aortic and intestinal anastomoses were performed on each animal for evaluation of short term response. The dogs with aortic anastomoses showed adequate healing at all doses with no evidence of suture line weakening. On long-term follow-up one animal (2000 rad) had stenosis at the anastomosis and one animal (4500 rad) developed an arteriovenous fistula. Three of the animals that had an intestinal blind loop irradiated subsequently developed intussusception, with the irradiated loop acting as the lead point. One week after irradiation, bursting pressure of an intestinal blind loop was normal at 3000 rad, but markedly decreased at 4500 rad. No late complications were noted after the irradiation of the intestinal anastomosis. No late complicatons were observed after irradiation of intestinal anastomoses, but one needs to be cautious with regards to possible late stenosis at the site of an irradiated vascular anastomosis.« less

Rare small intestinal volvulus from entrapment in hepato-diaphragmatic adhesions in a 45-year-old lady.

PubMed

Olaoye, Iyiade Olatunde; Adesina, Micheal Dapo

2016-12-20

Small intestinal volvulus is rare in adults and rarely caused by string adhesions between the liver and the diaphragm. Similar adhesions were described in Fitz-Hugh-Curtis syndrome. We report a 45-year-old lady with small intestinal volvulus from entrapment of a loop in string adhesions between the liver and the diaphragm. Her plain radiographs showed a significant shadow of the trapped loop. Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author 2016.

Transmigrated neutrophils in the intestinal lumen engage ICAM 1 to regulate the epithelial barrier and neutrophil recruitment

PubMed Central

Sumagin, Ronen; Robin, Alex Z.; Nusrat, Asma; Parkos, Charles A.

2014-01-01

Neutrophil (PMN) transepithelial migration (TEM) and accumulation in luminal spaces is a hallmark of mucosal inflammation. TEM has been extensively modeled, however the functional consequences and molecular basis of PMN interactions with luminal epithelial ligands are not clear. Here we report that cytokine-induced expression of a PMN ligand, intercellular adhesion molecule-1 (ICAM-1), exclusively on the luminal (apical) membrane of the intestinal epithelium results in accumulation and enhanced motility of transmigrated PMN on the apical epithelial surface. Using complementary in-vitro and in-vivo approaches we demonstrate that ligation of epithelial ICAM-1 by PMN or with specific antibodies results in myosin light chain kinase (MLCK)-dependent increases in epithelial permeability that are associated with enhanced PMN TEM. Effects of ICAM-1 ligation on epithelial permeability and PMN migration in-vivo were blocked after intraluminal addition of peptides derived from the cytoplasmic domain of ICAM-1. These findings provide new evidence for functional interactions between PMN and epithelial cells after migration into the intestinal lumen. While such interactions may aid in clearance of invading microorganisms by promoting PMN recruitment, engagement of ICAM-1 under pathologic conditions would increase accumulation of epithelial-associated PMN, thus contributing to mucosal injury as observed in conditions including ulcerative colitis. PMID:24345805

Pediatric lymphangiectasia: an imaging spectrum.

PubMed

Malone, Ladonna J; Fenton, Laura Z; Weinman, Jason P; Anagnost, Miran R; Browne, Lorna P

2015-04-01

Lymphangiectasia is a rarely encountered lymphatic dysplasia characterized by lymphatic dilation without proliferation. Although it can occur anywhere, the most common locations are the central conducting lymphatics and the pulmonary and intestinal lymphatic networks. Recent advances in lymphatic interventions have resulted in an increased reliance on imaging to characterize patterns of disease. To describe the patient populations, underlying conditions, and imaging features of lymphangiectasia encountered at a tertiary pediatric institution over a 10-year period and correlate these with pathology and patient outcomes. We retrospectively reviewed the pathology database from 2002 to 2012 to identify patients with pathologically or surgically proven lymphangiectasia who had undergone cross-sectional imaging. Medical records were reviewed for patient demographics, underlying conditions, treatment and outcome. Thirteen children were identified, ranging in age from 1 month to 16 years. Five had pulmonary lymphangiectasia, four intestinal and four diffuse involvement. Pulmonary imaging findings include diffuse or segmental interlobular septal thickening, pleural effusions and dilated mediastinal lymphatics. Intestinal imaging findings include focal or diffuse bowel wall thickening with central lymphatic dilation. Diffuse involvement included dilation of the central lymphatics and involvement of more than one organ system. Children with infantile presentation and diffuse pulmonary, intestinal or diffuse lymphatic abnormalities had a high mortality rate. Children with later presentations and segmental involvement demonstrated clinical improvement with occasional regression of disease. Three children with dilated central lymphatics on imaging underwent successful lymphatic duct ligation procedures with improved clinical course. Lymphangiectasia is a complex disorder with a spectrum of presentations, imaging appearances, treatments and outcomes. Cross-sectional imaging techniques distinguish segmental involvement of a single system (pulmonary or intestinal) from diffuse disease and may show dilated central conducting lymphatics, which may benefit from interventions such as ligation or occlusion.

Morphological and functional changes after benzalkonium chloride treatment of the small intestinal Thiry-Vella loop in rats.

PubMed

Móricz, K; Gyetvai, B; Bárdos, G

1998-08-01

The aim of this work was to study the effects of benzalkonium chloride (BAC) treatment on the small intestine and its functioning in rats surgically prepared with Thiry-Vella intestinal loop. The loops were treated with either BAC, which ablated much of the myenteric plexus and extrinsic innervation, or with physiological saline (SAL). In vivo drinking experiments were performed to examine the effect on fluid intake and behavioral indices of distending the loop with a balloon. Spontaneous motility and its changes induced by acetylcholine (ACh) and histamine (His) were studied on isolated stripes in vitro. Finally, samples from the loops were examined histologically. Though reduction of the cell number was less than expected and no differences of the thickness of the muscular layer between the two groups was observed, BAC treatment altered the pattern of spontaneous activity and also the sensitivity to ACh and His in isolated stripes. In vivo distension of the SAL-treated loops reduced fluid intake and produced signs of aversivity; these effects were absent in the BAC-treated group. Our results show that despite the differences in the degree of ablation from those obtained by others, BAC treatment can be used to study the mechanisms underlying the effects of the enteral stimuli on the behavior.

Percutaneous ligation of the left atrial appendage results in atrial electrical substrate modification.

PubMed

Syed, Faisal F; Rangu, Venu; Bruce, Charles J; Johnson, Susan B; Danielsen, Andrew; Gilles, Emily J; Ladewig, Dorothy J; Mikell, Susan B; Berhow, Steven; Wahnschaffe, Douglas; Suddendorf, Scott H; Asirvatham, Samuel J; Friedman, Paul A

2015-03-01

Debulking of electrically active atrial tissue may reduce the mass of fibrillating tissue during atrial fibrillation, eliminate triggers, and promote maintenance of normal sinus rhythm (NSR). We investigated whether left atrial appendage (LAA) ligation results in modification of atrial electrical substrate. Healthy male mongrel dogs (N = 20) underwent percutaneous epicardial LAA ligation. The ligation system grabber recorded LAA local electrograms (EGM) continuously before, during, and after closure. Successful ligation with a preloaded looped suture was confirmed intraprocedurally by LAA Doppler flow cessation on transesophageal echocardiography (TEE) and loss of LAA electrical activity, and after procedure by direct necropsic visualization. P-wave duration on surface electrocardiograms was measured immediately before and after LAA closure. Percent P-wave duration reduction was correlated with preclosure LAA internal dimensions measured by TEE and external dimensions measured on necropsy specimens to investigate associations of LAA geometry with the extent of electrical substrate modification. LAA ligation was successful in all dogs and accompanied by loss of LAA EGM. P-wave duration reduced immediately on ligation (mean 75 ms preligation to 63 ms postligation; mean difference ± standard error, 12 ± 1 ms; P < 0.0001). Percent P-wave reduction was associated with larger LAA longitudinal cross-sectional area (R(2) = 0.263, P = 0.04) and smaller external circumference (R(2) = 0.687, P = 0.04). All dogs were in sinus rhythm. Percutaneous LAA ligation results in its acute electrical isolation and atrial electrical substrate modification, the degree of which is associated with LAA geometry. These electrical changes raise the possibility that LAA ligation may promote NSR by removing LAA substrate and triggers. Copyright © 2015 Elsevier Inc. All rights reserved.

Toxin-neutralizing antibodies protect against Clostridium perfringens-induced necrosis in an intestinal loop model for bovine necrohemorrhagic enteritis.

PubMed

Goossens, Evy; Verherstraeten, Stefanie; Valgaeren, Bonnie R; Pardon, Bart; Timbermont, Leen; Schauvliege, Stijn; Rodrigo-Mocholí, Diego; Haesebrouck, Freddy; Ducatelle, Richard; Deprez, Piet R; Van Immerseel, Filip

2016-06-13

Bovine necrohemorrhagic enteritis is caused by Clostridium perfringens type A. Due to the rapid progress and fatal outcome of the disease, vaccination would be of high value. In this study, C. perfringens toxins, either as native toxins or after formaldehyde inactivation, were evaluated as possible vaccine antigens. We determined whether antisera raised in calves against these toxins were able to protect against C. perfringens challenge in an intestinal loop model for bovine necrohemorrhagic enteritis. Alpha toxin and perfringolysin O were identified as the most immunogenic proteins in the vaccine preparations. All vaccines evoked a high antibody response against the causative toxins, alpha toxin and perfringolysin O, as detected by ELISA. All antibodies were able to inhibit the activity of alpha toxin and perfringolysin O in vitro. However, the antibodies raised against the native toxins were more inhibitory to the C. perfringens-induced cytotoxicity (as tested on bovine endothelial cells) and only these antibodies protected against C. perfringens challenge in the intestinal loop model. Although immunization of calves with both native and formaldehyde inactivated toxins resulted in high antibody titers against alpha toxin and perfringolysin O, only antibodies raised against native toxins protect against C. perfringens challenge in an intestinal loop model for bovine necrohemorrhagic enteritis.

Oral administration of live- or heat-killed Candida albicans worsened cecal ligation and puncture sepsis in a murine model possibly due to an increased serum (1→3)-β-D-glucan.

PubMed

Panpetch, Wimonrat; Somboonna, Naraporn; Bulan, Dewi Embong; Issara-Amphorn, Jiraphorn; Finkelman, Malcolm; Worasilchai, Navaporn; Chindamporn, Ariya; Palaga, Tanapat; Tumwasorn, Somying; Leelahavanichkul, Asada

2017-01-01

Candida albicans is the most common fungus in the human intestinal microbiota but not in mice. To make a murine sepsis model more closely resemble human sepsis and to explore the role of intestinal C. albicans, in the absence of candidemia, in bacterial sepsis, live- or heat-killed C. albicans was orally administered to mice at 3h prior to cecal ligation and puncture (CLP). A higher mortality rate of CLP was demonstrated with Candida-administration (live- or heat-killed) prior to CLP. Fecal Candida presented only in experiments with live-Candida administration. Despite the absence of candidemia, serum (1→3)-β-D-glucan (BG) was higher in CLP with Candida-administration than CLP-controls (normal saline administration) at 6h and/or 18h post-CLP. Interestingly, fluconazole attenuated the fecal Candida burden and improved survival in mice with live-Candida administration, but not CLP-control. Microbiota analysis revealed increased Bacteroides spp. and reduced Lactobacillus spp. in feces after Candida administration. Additionally, synergy in the elicitation of cytokine production from bone marrow-derived macrophages, in vitro, was demonstrated by co-exposure to heat-killed E. coli and BG. In conclusion, intestinal abundance of fungi and/or fungal-molecules was associated with increased bacterial sepsis-severity, perhaps through enhanced cytokine elicitation induced by synergistic responses to molecules from gut-derived bacteria and fungi. Conversely, reducing intestinal fungal burdens decreased serum BG and attenuated sepsis in our model.

Inhibition of IKKβ in enterocytes exacerbates sepsis-induced intestinal injury and worsens mortality.

PubMed

Dominguez, Jessica A; Samocha, Alexandr J; Liang, Zhe; Burd, Eileen M; Farris, Alton B; Coopersmith, Craig M

2013-10-01

Nuclear factor-κB is a critical regulator of cell-survival genes and the host inflammatory response. The purpose of this study was to investigate the role of enterocyte-specific NF-kB in sepsis through selective ablation of IkB kinase. Prospective, randomized controlled study. Animal laboratories in university medical centers. Mice lacking functional NF-kB in their intestinal epithelium (Vil-Cre/Ikkβ) and wild-type mice were subjected to sham laparotomy or cecal ligation and puncture. Animals were killed at 24 hours or followed 7 days for survival. Septic wild-type mice had decreased villus length compared with sham mice, whereas villus atrophy was further exacerbated in septic Vil-Cre/Ikkβ mice. Sepsis induced an increase in intestinal epithelial apoptosis compared with sham mice, which was further exacerbated in Vil-Cre/Ikkβ mice. Sepsis induced intestinal hyperpermeability in wild-type mice compared with sham mice, which was further exacerbated in septic Vil-Cre/Ikkβ mice. This was associated with increased intestinal expression of claudin-2 in septic wild-type mice, which was further increased in septic Vil-Cre/Ikkβ mice. Both, pro-inflammatory and anti-inflammatory cytokines were increased in serum following cecal ligation and puncture, and interleukin 10 and monocyte chemoattractant protein-1 levels were higher in septic Vil-Cre/Ikkβ mice than in septic wild-type mice. All septic mice were bacteremic, but no differences in bacterial load were identified between wild-type and Vil-Cre/Ikkβ mice. To determine the functional significance of these results, animals were followed for survival. Septic wild-type mice had lower mortality than septic Vil-Cre/Ikkβ mice (47% vs 80%, p<0.05). Antitumor necrosis factor administration decreased intestinal apoptosis, permeability, and mortality in wild-type septic mice, and a similar improvement in intestinal integrity and survival were seen when antitumor necrosis factor was given to Vil-Cre/Ikkβ mice. Enterocyte-specific NF-kB has a beneficial role in sepsis by partially preventing sepsis-induced increases in apoptosis and permeability, which are associated with worsening mortality.

Effects of Clostridium perfringens iota toxin in the small intestine of mice.

PubMed

Redondo, Leandro M; Redondo, Enzo A; Dailoff, Gabriela C; Leiva, Carlos L; Díaz-Carrasco, Juan M; Bruzzone, Octavio A; Cangelosi, Adriana; Geoghegan, Patricia; Fernandez-Miyakawa, Mariano E

2017-12-01

Iota toxin is a binary toxin solely produced by Clostridium perfringens type E strains, and is structurally related to CDT from C. difficile and CST from C. spiroforme. As type E causes hemorrhagic enteritis in cattle, it is usually assumed that associated diseases are mediated by iota toxin, although evidence in this regard has not been provided. In the present report, iota toxin intestinal effects were evaluated in vivo using a mouse model. Histological damage was observed in ileal loops treated with purified iota toxin after 4 h of incubation. Luminal iota toxin induced fluid accumulation in the small intestine in a dose dependent manner, as determined by the enteropooling and the intestinal loop assays. None of these changes were observed in the large intestine. These results suggest that C. perfringens iota toxin alters intestinal permeability, predominantly by inducing necrosis and degenerative changes in the mucosal epithelium of the small intestine, as well as changes in intestinal motility. The obtained results suggest a central role for iota toxin in the pathogenesis of C. perfringens type E hemorrhagic enteritis, and contribute to remark the importance of clostridial binary toxins in digestive diseases. Published by Elsevier Ltd.

Intestinal volvulus with coagulative hepatic necrosis in a chicken.

PubMed

Haridy, Mohie; Goryo, Masanobu; Sasaki, Jun; Okada, Kosuke

2010-04-01

A 7-week-old SPF chicken inoculated at 4 weeks of age with chicken anemia virus was puffed up depressed and had ruffled feathers and a good body condition. Intestinal volvulus involving the jejunum and part of the duodenum forming two loops with one knob was observed. Microscopically, venous infarction of the obstructed loops, periportal and sublobular multifocal coagulative hepatic necrosis and granulomatous inflammation of the cecal tonsils were observed. Gram staining revealed no bacteria in hepatic tissue; however, gram-positive bacilli were detected in the necrotic debris in the intestinal lumen. Immunosuppression might have predisposed the chicken to intestinal and cecal tonsil infection that then progressed to volvulus. Loss of the mucosal barrier in infarction might allow bacterial toxins and vasoactive factors to escape into the systemic circulation (toxemia) and be responsible for the hepatic necrosis.

Regulation of antibacterial defense in the small intestine by the nuclear bile acid receptor.

PubMed

Inagaki, Takeshi; Moschetta, Antonio; Lee, Youn-Kyoung; Peng, Li; Zhao, Guixiang; Downes, Michael; Yu, Ruth T; Shelton, John M; Richardson, James A; Repa, Joyce J; Mangelsdorf, David J; Kliewer, Steven A

2006-03-07

Obstruction of bile flow results in bacterial proliferation and mucosal injury in the small intestine that can lead to the translocation of bacteria across the epithelial barrier and systemic infection. These adverse effects of biliary obstruction can be inhibited by administration of bile acids. Here we show that the farnesoid X receptor (FXR), a nuclear receptor for bile acids, induces genes involved in enteroprotection and inhibits bacterial overgrowth and mucosal injury in ileum caused by bile duct ligation. Mice lacking FXR have increased ileal levels of bacteria and a compromised epithelial barrier. These findings reveal a central role for FXR in protecting the distal small intestine from bacterial invasion and suggest that FXR agonists may prevent epithelial deterioration and bacterial translocation in patients with impaired bile flow.

Splanchnic-aortic inflammatory axis in experimental portal hypertension

PubMed Central

Aller, Maria-Angeles; de las Heras, Natalia; Nava, Maria-Paz; Regadera, Javier; Arias, Jaime; Lahera, Vicente

2013-01-01

Splanchnic and systemic low-grade inflammation has been proposed to be a consequence of long-term prehepatic portal hypertension. This experimental model causes minimal alternations in the liver, thus making a more selective study possible for the pathological changes characteristic of prehepatic portal hypertension. Low-grade splanchnic inflammation after long-term triple partial portal vein ligation could be associated with liver steatosis and portal hypertensive intestinal vasculopathy. In fact, we have previously shown that prehepatic portal hypertension in the rat induces liver steatosis and changes in lipid and carbohydrate metabolism similar to those produced in chronic inflammatory conditions described in metabolic syndrome in humans. Dysbiosis and bacterial translocation in this experimental model suggest the existence of a portal hypertensive intestinal microbiome implicated in both the splanchnic and systemic alterations related to prehepatic portal hypertension. Among the systemic impairments, aortopathy characterized by oxidative stress, increased levels of proinflammatory cytokines and profibrogenic mediators stand out. In this experimental model of long-term triple portal vein ligated-rats, the abdominal aortic proinflammatory response could be attributed to oxidative stress. Thus, the increased aortic reduced-nicotinamide-adenine dinucleotide phosphate [NAD(P)H] oxidase activity could be associated with reactive oxygen species production and promote aortic inflammation. Also, oxidative stress mediated by NAD(P)H oxidase has been associated with risk factors for inflammation and atherosclerosis. The splanchnic and systemic pathology that is produced in the long term after triple partial portal vein ligation in the rat reinforces the validity of this experimental model to study the chronic low-grade inflammatory response induced by prehepatic portal hypertension. PMID:24307792

[Anisoperistaltic Roux-en-Y reconstruction: rare cause for recurrent cholangitis after hepatic jejunostomy].

PubMed

Böhm, S A; Beckurts, K T; Landwehr, P; Hölscher, A H

1999-07-01

Stenosis of the hepatico-intestinal anastomosis after hepaticojejunostomy is a common cause for recurrent cholangitis. In the following report a patient's history of recurrent cholangitis after hepaticojejunostomy performed because of bile duct injury is presented. Preoperative imaging revealed a stricture of the hepatico-intestinal anastomosis and a massive dilatation of the Roux-en-Y loop, so that a draining disorder was assumed. Laparotomy showed an anisoperistaltic Roux-en-Y loop. When assessing the differential diagnosis of recurrent cholangitis after hepaticojejunostomy, anisoperistaltic reconstruction should be considered.

Clostridium perfringens epsilon toxin is absorbed from different intestinal segments of mice.

PubMed

Losada-Eaton, D M; Uzal, F A; Fernández Miyakawa, M E

2008-06-01

Clostridium perfringens epsilon toxin is a potent toxin responsible for a rapidly fatal enterotoxaemia in several animal species. The pathogenesis of epsilon toxin includes toxicity to endothelial cells and neurons. Although epsilon toxin is absorbed from the gastrointestinal tract, the intestinal regions where the toxin is absorbed and the conditions favoring epsilon toxin absorption are unknown. The aim of this paper was to determine the toxicity of epsilon toxin absorbed from different gastrointestinal segments of mice and to evaluate the influence of the intestinal environment in the absorption of this toxin. Epsilon toxin diluted in one of several different saline solutions was surgically introduced into ligated stomach or intestinal segments of mice. Comparison of the toxicity of epsilon toxin injected in different sections of the gastrointestinal tract showed that this toxin can be absorbed from the small and the large intestine but not from the stomach of mice. The lethality of epsilon toxin was higher when this toxin was injected in the colon than in the small intestine. Low pH, and Na(+) and glucose added to the saline solution increased the toxicity of epsilon toxin injected into the small intestine. This study shows that absorption of epsilon toxin can occur in any intestinal segment of mice and that the physicochemical characteristics of the intestinal content can affect the absorption of this toxin.

Dendritic cells are early cellular targets of Listeria monocytogenes after intestinal delivery and are involved in bacterial spread in the host.

PubMed

Pron, B; Boumaila, C; Jaubert, F; Berche, P; Milon, G; Geissmann, F; Gaillard, J L

2001-05-01

We studied the sequence of cellular events leading to the dissemination of Listeria monocytogenes from the gut to draining mesenteric lymph nodes (MLNs) by confocal microscopy of immunostained tissue sections from a rat ligated ileal loop system. OX-62-positive cells beneath the epithelial lining of Peyer's patches (PPs) were the first Listeria targets identified after intestinal inoculation. These cells had other features typical of dendritic cells (DCs): they were large, pleiomorphic and major histocompatibility complex class II(hi). Listeria were detected by microscopy in draining MLNs as early as 6 h after inoculation. Some 80-90% of bacteria were located in the deep paracortical regions, and 100% of the bacteria were present in OX-62-positive cells. Most infected cells contained more than five bacteria each, suggesting that they had arrived already loaded with bacteria. At later stages, the bacteria in these areas were mostly present in ED1-positive mononuclear phagocytes. These cells were also infected by an actA mutant defective in cell-to-cell spreading. This suggests that Listeria are transported by DCs from PPs to the deep paracortical regions of draining MLNs and are then transmitted to other cell populations by mechanisms independent of ActA. Another pathway of dissemination to MLNs was identified, probably involving free Listeria and leading to the infection of ED3-positive mononuclear phagocytes in the subcapsular sinus and adjacent paracortical areas. This study provides evidence that DCs are major cellular targets of L. monocytogenes in PPs and that DCs may be involved in the early dissemination of this pathogen. DCs were not sites of active bacterial replication, making these cells ideal vectors of infection.

Toll-like receptors and intestinal defence: molecular basis and therapeutic implications.

PubMed

Cario, Elke

2003-07-07

Toll-like receptors (TLRs) play a principle role in distinct pathogen recognition and in the initiation of innate immune responses of the intestinal mucosa. Activated innate immunity interconnects downstream with adaptive immunity in complex feedback regulatory loops. Intestinal disease might result from inappropriate activation of the mucosal immune system driven by TLRs in response to normal luminal flora.

Studying DNA looping by single-molecule FRET.

PubMed

Le, Tung T; Kim, Harold D

2014-06-28

Bending of double-stranded DNA (dsDNA) is associated with many important biological processes such as DNA-protein recognition and DNA packaging into nucleosomes. Thermodynamics of dsDNA bending has been studied by a method called cyclization which relies on DNA ligase to covalently join short sticky ends of a dsDNA. However, ligation efficiency can be affected by many factors that are not related to dsDNA looping such as the DNA structure surrounding the joined sticky ends, and ligase can also affect the apparent looping rate through mechanisms such as nonspecific binding. Here, we show how to measure dsDNA looping kinetics without ligase by detecting transient DNA loop formation by FRET (Fluorescence Resonance Energy Transfer). dsDNA molecules are constructed using a simple PCR-based protocol with a FRET pair and a biotin linker. The looping probability density known as the J factor is extracted from the looping rate and the annealing rate between two disconnected sticky ends. By testing two dsDNAs with different intrinsic curvatures, we show that the J factor is sensitive to the intrinsic shape of the dsDNA.

Studying DNA Looping by Single-Molecule FRET

PubMed Central

Le, Tung T.; Kim, Harold D.

2014-01-01

Bending of double-stranded DNA (dsDNA) is associated with many important biological processes such as DNA-protein recognition and DNA packaging into nucleosomes. Thermodynamics of dsDNA bending has been studied by a method called cyclization which relies on DNA ligase to covalently join short sticky ends of a dsDNA. However, ligation efficiency can be affected by many factors that are not related to dsDNA looping such as the DNA structure surrounding the joined sticky ends, and ligase can also affect the apparent looping rate through mechanisms such as nonspecific binding. Here, we show how to measure dsDNA looping kinetics without ligase by detecting transient DNA loop formation by FRET (Fluorescence Resonance Energy Transfer). dsDNA molecules are constructed using a simple PCR-based protocol with a FRET pair and a biotin linker. The looping probability density known as the J factor is extracted from the looping rate and the annealing rate between two disconnected sticky ends. By testing two dsDNAs with different intrinsic curvatures, we show that the J factor is sensitive to the intrinsic shape of the dsDNA. PMID:24998459

In vivo multiphoton imaging of bile duct ligation

NASA Astrophysics Data System (ADS)

Liu, Yuan; Li, Feng-Chieh; Chen, Hsiao-Chin; Chang, Po-shou; Yang, Shu-Mei; Lee, Hsuan-Shu; Dong, Chen-Yuan

2008-02-01

Bile is the exocrine secretion of liver and synthesized by hepatocytes. It is drained into duodenum for the function of digestion or drained into gallbladder for of storage. Bile duct obstruction is a blockage in the tubes that carry bile to the gallbladder and small intestine. However, Bile duct ligation results in the changes of bile acids in serum, liver, urine, and feces1, 2. In this work, we demonstrate a novel technique to image this pathological condition by using a newly developed in vivo imaging system, which includes multiphoton microscopy and intravital hepatic imaging chamber. The images we acquired demonstrate the uptake, processing of 6-CFDA in hepatocytes and excretion of CF in the bile canaliculi. In addition to imaging, we can also measure kinetics of the green fluorescence intensity.

A hazard of lingual orthodontic attachments: a case report.

PubMed

Oliver, Graham; Borumandi, Farzad

2015-01-01

A case is presented of an unusual trauma to the floor of mouth caused by an unused lingual orthodontic button. This resulted in a vein being stripped from the floor of mouth and was associated with severe pain and restricted tongue movement. Management was by ligation and excision of the loop of the vessel under local anaesthesia.

Bile acid receptor TGR5 overexpression is associated with decreased intestinal mucosal injury and epithelial cell proliferation in obstructive jaundice.

PubMed

Ji, Chen-Guang; Xie, Xiao-Li; Yin, Jie; Qi, Wei; Chen, Lei; Bai, Yun; Wang, Na; Zhao, Dong-Qiang; Jiang, Xiao-Yu; Jiang, Hui-Qing

2017-04-01

Bile acids stimulate intestinal epithelial proliferation in vitro. We sought to investigate the role of the bile acid receptor TGR5 in the protection of intestinal epithelial proliferation in obstructive jaundice. Intestinal tissues and serum samples were obtained from patients with malignant obstructive jaundice and from bile duct ligation (BDL) rats. Intestinal permeability and morphological changes in the intestinal mucosa were observed. The functions of TGR5 in cell proliferation in intestinal epithelial injury were determined by overexpression or knockdown studies in Caco-2 and FHs 74 Int cells pretreated with lipopolysaccharide (LPS). Internal biliary drainage was superior to external biliary drainage in recovering intestinal permeability and mucosal histology in patients with obstructive jaundice. In BDL rats, feeding of chenodeoxycholic acid (CDCA) decreased intestinal mucosa injury. The levels of PCNA, a marker of proliferation, increased in response to CDCA feeding and were paralleled by elevated TGR5 expression. CDCA upregulated TGR5 expression and promoted proliferation in Caco-2 and FHs 74 Int cells pretreated with LPS. Overexpression of TGR5 resulted in increased PCNA, cell viability, EdU incorporation, and the proportion of cells in S phase, whereas knockdown of TGR5 had the opposite effect. Our data indicate that bile acids promote intestinal epithelial cell proliferation and decrease mucosal injury by upregulating TGR5 expression in obstructive jaundice. Copyright © 2016 Elsevier Inc. All rights reserved.

Pylorus preserving loop duodeno-enterostomy with sleeve gastrectomy - preliminary results

PubMed Central

2014-01-01

Background Bariatric operations mostly combine a restrictive gastric component with a rerouting of the intestinal passage. The pylorus can thereby be alternatively preserved or excluded. With the aim of performing a “pylorus-preserving gastric bypass”, we present early results of a proximal postpyloric loop duodeno-jejunostomy associated with a sleeve gastrectomy (LSG) compared to results of a parallel, but distal LSG with a loop duodeno-ileostomy as a two-step procedure. Methods 16 patients underwent either a two-step LSG with a distal loop duodeno-ileostomy (DIOS) as revisional bariatric surgery or a combined single step operation with a proximal duodeno-jejunostomy (DJOS). Total small intestinal length was determined to account for inter-individual differences. Results Mean operative time for the second-step of the DIOS operation was 121 min and 147 min for the combined DJOS operation. The overall intestinal length was 750.8 cm (range 600-900 cm) with a bypassed limb length of 235.7 cm in DJOS patients. The mean length of the common channel in DIOS patients measured 245.6 cm. Overall excess weight loss (%EWL) of the two-step DIOS procedure came to 38.31% and 49.60%, DJOS patients experienced an %EWL of 19.75% and 46.53% at 1 and 6 months, resp. No complication related to the duodeno-enterostomy occurred. Conclusions Loop duodeno-enterosomies with sleeve gastrectomy can be safely performed and may open new alternatives in bariatric surgery with the possibility for inter-individual adaptation. PMID:24725654

Targeting Nuclear Receptors to Treat Fibrostenotic Crohn’s Disease

DTIC Science & Technology

2017-08-01

feedback loop . 15. SUBJECT TERMS Crohn’s disease, intestinal smooth muscle, intestinal fibroblasts, NR4A1, 6-MP, Cytosporone B, proliferation, inflammation...whether the exaggerated tissue remodelling observed in our studies reflects a hyper -fibrotic response, versus a hyper -inflammatory phenotype

Intestinal absorption of dideoxynucleosides: characterization using a multiloop in situ technique.

PubMed

Mirchandani, H L; Chien, Y W

1995-01-01

The intestinal absorption of dideoxynucleosides was studied in rabbits, using a closed-loop mesenteric-sampling in situ technique developed in this laboratory, and the kinetic profiles were characterized. Each of the dideoxynucleosides exhibited different dependence on the intestinal regions studied: 3'-azido-2',3'-dideoxythymidine was best absorbed from the ileum, while 2',3'-dideoxyinosine and 2',3'-dideoxycytidine were preferentially absorbed from the jejunum. The results were validated by the mass-balance approach; the percent of drug retained in the intestinal lumen and that degraded at the intestinal pH, by colonic flora, in the intestinal tissue, and in plasma were assessed.

Ultrasonographic evaluation of abdominal distension in 52 camels (Camelus dromedarius).

PubMed

Tharwat, Mohamed; Al-Sobayil, Fahd; Ali, Ahmed; Buczinski, Sébastien

2012-08-01

The purpose of this study was to assess the diagnostic value of ultrasonography in the evaluation of abdominal distension in 52 camels (Camelus dromedarius). The conditions included trypanosomiasis (n=35), intestinal obstruction (n=12) and ruptured urinary bladder (n=5). Fifteen clinically normal camels were included as controls. Transabdominal and transrectal ultrasonography was carried out on all camels. In animals with trypanosomiasis, ultrasonographic findings included accumulation of massive amounts of hypoechoic abdominal fluids where liver, intestine, kidney, spleen and urinary bladder were imaged floating. Except in two cases of bile duct calcification and one of hepatic abscessation, no detectable abnormal sonographic lesions were detected while imaging the hepatic and renal parenchyma, and the heart and its valves and major blood vessels. In camels with intestinal obstruction, ultrasonographic findings included distended intestinal loops with markedly reduced or absent motility. In one camel, the intestinal lumen contained localised hyperechoic material that was consistent with a foreign body. Hypoechoic fluid with or without fibrin was seen between intestinal loops. In camels with ruptured urinary bladder, ultrasonographic findings included collapsed and perforated bladder, echogenic blood clots within the urinary bladder and peritoneal cavity, increased thickness of the bladder wall, floating intestines in hypoechogenic fluid and echogenic calculi within the urethra. Ultrasonography was considered a useful tool for the evaluation of dromedary camels with abdominal distension. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of honey on bacterial translocation and intestinal morphology in obstructive jaundice

PubMed Central

Gencay, Cem; Kilicoglu, Sibel Serin; Kismet, Kemal; Kilicoglu, Bulent; Erel, Serap; Muratoglu, Sabahattin; Sunay, Asli Elif; Erdemli, Esra; Akkus, Mehmet Ali

2008-01-01

AIM: To evaluate the effects of honey on bacterial translocation and intestinal villus histopathology in experimental obstructive jaundice. METHODS: Thirty Wistar-Albino rats were randomly divided into three groups each including 10 animals: group I, sham-operated; group II, ligation and section of the common bile duct (BDL); group III, bile duct ligation followed by oral supplementation of honey (BDL + honey) 10 g/kg per day. Liver, blood, spleen, mesenteric lymph nodes, and ileal samples were taken for microbiological, light and transmission electrone microscopic examination. RESULTS: Although the number of villi per centimeter and the height of the mucosa were higher in sham group, there was no statistically significant difference between sham and BDL + honey groups (P > 0.05). On the other hand, there was a statistically significant difference between BDL group and other groups (P < 0.05). The electron microscopic changes were also different between these groups. Sham and honey groups had similar incidence of bacterial translocation (P > 0.05). BDL group had significantly higher rates of bacterial translocation as compared with sham and honey groups. Bacterial translocation was predominantly detected in mesenteric lymph nodes. CONCLUSION: Supplementation of honey in presence of obstructive jaundice ameliorates bacterial translocation and improves ileal morphology. PMID:18528939

Corroboration of naringin effects on the intestinal absorption and pharmacokinetic behavior of candesartan cilexetil solid dispersions using in-situ rat models.

PubMed

Surampalli, Gurunath; K Nanjwade, Basavaraj; Patil, P A

2015-01-01

The aim of this study was to corroborate the effects of naringin, a P-glycoprotein inhibitor, on the intestinal absorption and pharmacokinetics of candesartan (CDS) from candesartan cilexetil (CAN) solid dispersions using in-situ rat models. Intestinal transport and absorption studies were examined by in-situ single pass perfusion and closed-loop models. We evaluated the intestinal membrane damage in the presence of naringin by measuring the release of protein and alkaline phosphatase (ALP). We noticed 1.47-fold increase in Peff of CDS from freeze-dried CAN-loaded solid dispersions with naringin (15 mg/kg, w/w) when compared with freeze-dried solid dispersion without naringin using in-situ single pass intestinal perfusion model. However, no intestinal membrane damage was observed in the presence of naringin. Our findings from in-situ closed-loop pharmacokinetic studies showed 1.34-fold increase in AUC with elevated Cmax and shortened tmax for freeze-dried solid dispersion with naringin as compared to freeze-dried solid dispersion without naringin. This study demonstrated that increased solubilization (favored by freeze-dried solid dispersion) and efflux pump inhibition (using naringin), the relative bioavailability of CDS can be increased, suggesting an alternative potential for improving oral bioavailability of CAN.

The Bile Acid Receptor GPBAR-1 (TGR5) Modulates Integrity of Intestinal Barrier and Immune Response to Experimental Colitis

PubMed Central

Cipriani, Sabrina; Mencarelli, Andrea; Chini, Maria Giovanna; Distrutti, Eleonora; Renga, Barbara; Bifulco, Giuseppe; Baldelli, Franco; Donini, Annibale; Fiorucci, Stefano

2011-01-01

Background GP-BAR1, a member G protein coupled receptor superfamily, is a cell surface bile acid-activated receptor highly expressed in the ileum and colon. In monocytes, ligation of GP-BAR1 by secondary bile acids results in a cAMP-dependent attenuation of cytokine generation. Aims To investigate the role GP-BAR1 in regulating intestinal homeostasis and inflammation-driven immune dysfunction in rodent models of colitis. Methods Colitis was induced in wild type and GP-BAR1−/− mice by DSS and TNBS administration. Potential GP-BAR1 agonists were identified by in silico screening and computational docking studies. Results GP-BAR1−/− mice develop an abnormal morphology of colonic mucous cells and an altered molecular architecture of epithelial tight junctions with increased expression and abnormal subcellular distribution of zonulin 1 resulting in increased intestinal permeability and susceptibility to develop severe colitis in response to DSS at early stage of life. By in silico screening and docking studies we identified ciprofloxacin as a GP-BAR1 ligand. In monocytes, ciprofloxacin increases cAMP concentrations and attenuates TNFα release induced by TLR4 ligation in a GP-BAR1 dependent manner. Treating mice rendered colitic by TNBS with ciprofloxacin and oleanolic acid, a well characterized GP-BAR1 ligand, abrogates signs and symptoms of colitis. Colonic expression of GP-BAR1 mRNA increases in rodent models of colitis and tissues from Crohn's disease patients. Flow cytometry analysis demonstrates that ≈90% of CD14+ cells isolated from the lamina propria of TNBS-treated mice stained positively for GP-BAR1. Conclusions GP-BAR1 regulates intestinal barrier structure. Its expression increases in rodent models of colitis and Crohn's disease. Ciprofloxacin is a GP-BAR1 ligand. PMID:22046243

Mitochondrial dysfunction is responsible for the intestinal calcium absorption inhibition induced by menadione.

PubMed

Marchionatti, Ana M; Perez, Adriana V; Diaz de Barboza, Gabriela E; Pereira, Beatriz M; Tolosa de Talamoni, Nori G

2008-02-01

Menadione (MEN) inhibits intestinal calcium absorption by a mechanism not completely understood. The aim of this work was to find out the role of mitochondria in this inhibitory mechanism. Hence, normal chicks treated with one i.p. dose of MEN were studied in comparison with controls. Intestinal calcium absorption was measured by the in situ ligated intestinal segment technique. GSH, oxidoreductase activities from the Krebs cycle and enzymes of the antioxidant system were measured in isolated mitochondria. Mitochondrial membrane potential was measured by a flow cytometer technique. DNA fragmentation and cytochrome c localization were determined by immunocytochemistry. Data indicate that in 30 min, MEN decreases intestinal Ca(2+) absorption, which returns to the control values after 10 h. GSH was only decreased for half an hour, while the activity of malate dehydrogenase and alpha-ketoglutarate dehydrogenase was diminished for 48 h. Mn(2+)-superoxide dismutase activity was increased in 30 min, whereas the activity of catalase and glutathione peroxidase remained unaltered. DNA fragmentation and cytochrome c release were maximal in 30 min, but were recovered after 15 h. In conclusion, MEN inhibits intestinal Ca(2+) absorption by mitochondrial dysfunction as revealed by GSH depletion and alteration of the permeability triggering the release of cytochrome c and DNA fragmentation.

Fetal midgut volvulus: report of eight cases.

PubMed

Sciarrone, A; Teruzzi, E; Pertusio, A; Bastonero, S; Errante, G; Todros, T; Viora, E

2016-01-01

To evaluate whether prenatal diagnosis of intestinal midgut volvulus (a rare condition due to the small bowel loops twisting) can improve the prognosis of the newborns. In our Prenatal Diagnosis Center, eight cases of intestinal volvulus observed between 2007 and 2014 were retrospectively considered. Ultrasonographic signs can be direct and specific (whirlpool sign, coffee bean sign) or indirect and non-specific (abdominal mass, dilated bowel loops, pseudocysts, ascites, polyhydramnios). Prenatal diagnosis was performed at 20-34 weeks of gestation. All newborns were exposed to an emergency surgery: the major complication was due to cystic fibrosis. An early suspicion of intestinal volvulus allows the clinician to refer the patient to a tertiary center so to confirm the diagnosis and perform an appropriate follow-up in order to identify the proper time of delivery. The prognosis of the babies with prenatal intestinal volvulus depends on the length of the segment involved, on the level of intestinal obstruction, on the presence of meconium peritonitis and on the gestational age at birth. Our experience, according with the literature, suggests that ascites and absence of abdominal peristalsis are ultrasonographic signs that, in the third trimester of pregnancy, correctly lead to an immediate delivery intervention.

The role of curcumin on intestinal oxidative stress, cell proliferation and apoptosis after ischemia/reperfusion injury in rats.

PubMed

Yucel, Ahmet Fikret; Kanter, Mehmet; Pergel, Ahmet; Erboga, Mustafa; Guzel, Ahmet

2011-12-01

The aim of this study was to demonstrate the role of curcumin on oxidative stress, cell proliferation and apoptosis in the rat intestinal mucosa after ischemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into three groups: sham, I/R and I/R+ curcumin; each group contain 10 animals. Sham group animals underwent laparotomy without I/R injury. After I/R groups animals underwent laparotomy, 1 h of superior mesenteric artery ligation were followed by 1 h of reperfusion. In the curcumin group, 3 days before I/R, curcumin (100 mg/kg) was administered by gastric gavage. All animals were sacrificed at the end of reperfusion and intestinal tissues samples were obtained for biochemical and histopathological investigation in all groups. Curcumin treatment significantly decreased the elevated tissue malondialdehyde levels and increased of reduced superoxide dismutase, and glutathione peroxidase enzyme activities in intestinal tissues samples. I/R caused severe histopathological injury including mucosal erosions and villous congestion and hemorrhage. Curcumin treatment significantly attenuated the severity of intestinal I/R injury, with inhibiting of I/R-induced apoptosis and cell proliferation. These results suggest that curcumin treatment has a protective effect against intestinal damage induced by intestinal I/R. This protective effect is possibly due to its ability to inhibit I/R-induced oxidative stress, apoptosis and cell proliferation.

Anti-inflammatory and antioxidant effects of infliximab in a rat model of intestinal ischemia/reperfusion injury.

PubMed

Pergel, Ahmet; Kanter, Mehmet; Yucel, Ahmet Fikret; Aydin, Ibrahim; Erboga, Mustafa; Guzel, Ahmet

2012-11-01

The aim of this study was to investigate the possible protective effects of infliximab on oxidative stress, cell proliferation and apoptosis in the rat intestinal mucosa after ischemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into three groups: sham, I/R and I/R+ infliximab; each group comprised 10 animals. Sham group animals underwent laparotomy without I/R injury. I/R groups after undergoing laparotomy, 1 hour of superior mesenteric artery ligation occurred, which was followed by 1 hour of reperfusion. In the infliximab group, 3 days before I/R, infliximab (3 mg/kg) was administered intravenously. All animals were killed at the end of reperfusion and intestinal tissues samples were obtained for biochemical and histopathological investigation in all groups. To date, no biochemical and histopathological changes have been reported regarding intestinal I/R injury in rats due to infliximab treatment. Infliximab treatment significantly decreased the elevated tissue malondialdehyde levels and increased reduced superoxide dismutase and glutathione peroxidase enzyme activities in intestinal tissues samples. I/R caused severe histopathological injury including mucosal erosions, inflammatory cell infiltration, necrosis, hemorrhage, and villous congestion. Infliximab treatment significantly attenuated the severity of intestinal I/R injury, inhibiting I/R-induced apoptosis, and cell proliferation. Because of its anti-inflammatory and antioxidant effects, infliximab pretreatment may have protective effects on the experimental intestinal I/R model of rats.

In-situ intestinal rat perfusions for human Fabs prediction and BCS permeability class determination: Investigation of the single-pass vs. the Doluisio experimental approaches.

PubMed

Lozoya-Agullo, Isabel; Zur, Moran; Wolk, Omri; Beig, Avital; González-Álvarez, Isabel; González-Álvarez, Marta; Merino-Sanjuán, Matilde; Bermejo, Marival; Dahan, Arik

2015-03-01

Intestinal drug permeability has been recognized as a critical determinant of the fraction dose absorbed, with direct influence on bioavailability, bioequivalence and biowaiver. The purpose of this research was to compare intestinal permeability values obtained by two different intestinal rat perfusion methods: the single-pass intestinal perfusion (SPIP) model and the Doluisio (closed-loop) rat perfusion method. A list of 15 model drugs with different permeability characteristics (low, moderate, and high, as well as passively and actively absorbed) was constructed. We assessed the rat intestinal permeability of these 15 model drugs in both SPIP and the Doluisio methods, and evaluated the correlation between them. We then evaluated the ability of each of these methods to predict the fraction dose absorbed (Fabs) in humans, and to assign the correct BCS permeability class membership. Excellent correlation was obtained between the two experimental methods (r(2)=0.93). An excellent correlation was also shown between literature Fabs values and the predictions made by both rat perfusion techniques. Similar BCS permeability class membership was designated by literature data and by both SPIP and Doluisio methods for all compounds. In conclusion, the SPIP model and the Doluisio (closed-loop) rat perfusion method are both equally useful for obtaining intestinal permeability values that can be used for Fabs prediction and BCS classification. Copyright © 2015 Elsevier B.V. All rights reserved.

Murine Pancreatic Cancer Alters T Cell Activation and Apoptosis and Worsens Survival After Cecal Ligation and Puncture.

PubMed

Lyons, John D; Chen, Ching-Wen; Liang, Zhe; Zhang, Wenxiao; Chihade, Deena B; Burd, Eileen M; Farris, Alton B; Ford, Mandy L; Coopersmith, Craig

2018-06-08

Patients with cancer who develop sepsis have a markedly higher mortality than patients who were healthy prior to the onset of sepsis. Potential mechanisms underlying this difference have previously been examined in two preclinical models of cancer followed by sepsis. Both pancreatic cancer/pneumonia and lung cancer/cecal ligation and puncture (CLP) increase murine mortality, associated with alterations in lymphocyte apoptosis and intestinal integrity. However, pancreatic cancer/pneumonia decreases lymphocyte apoptosis and increases gut apoptosis while lung cancer/CLP increases lymphocyte apoptosis and decreases intestinal proliferation. These results cannot distinguish the individual roles of cancer versus sepsis since different models of each were used. We therefore created a new cancer/sepsis model to standardize each variable. Mice were injected with a pancreatic cancer cell line and three weeks later cancer mice and healthy mice were subjected to CLP. Cancer septic mice had a significantly higher 10-day mortality than previously healthy septic mice. Cancer septic mice had increased CD4 T cells and CD8 T cells, associated with decreased CD4 T cell apoptosis 24 hours after CLP. Further, splenic CD8+ T cell activation was decreased in cancer septic mice. In contrast, no differences were noted in intestinal apoptosis, proliferation or permeability, nor were changes noted in local bacterial burden, renal, liver or pulmonary injury. Cancer septic mice thus have consistently reduced survival compared to previously healthy septic mice, independent of the cancer or sepsis model utilized. Changes in lymphocyte apoptosis are common to cancer model and independent of sepsis model whereas gut apoptosis is common to sepsis model and independent of cancer model. The host response to the combination of cancer and sepsis is dependent, at least in part, on both chronic co-morbidity and acute illness.

Glutamine supplementation improves intestinal barrier function in a weaned piglet model of Escherichia coli infection.

PubMed

Ewaschuk, Julia B; Murdoch, Gordon K; Johnson, Ian R; Madsen, Karen L; Field, Catherine J

2011-09-01

The weaning period is associated with an increased prevalence of gastrointestinal infection in many species. Glutamine (Gln) has been shown to improve intestinal barrier function and immune function in both in vivo and in vitro models. The objective of the present study was to determine the effect of dietary Gln supplementation on intestinal barrier function and intestinal cytokines in a model of Escherichia coli infection. We randomised 21-d-old piglets (n 20) to nutritionally complete isonitrogenous diets with or without Gln (4·4 %, w/w) for 2 weeks. Intestinal loops were isolated from anaesthetised pigs and inoculated with either saline or one of the two E. coli (K88AC or K88 wild-type)-containing solutions. Intestinal tissue was studied for permeability, cytokine expression, fluid secretion and tight-junction protein expression. Animals receiving Gln supplementation had decreased potential difference (PD) and short-circuit current (I(sc)) in E. coli-inoculated intestinal loops (PD 0·628 (SEM 0·151) mV; I(sc) 13·0 (SEM 3·07) μA/cm(2)) compared with control-fed animals (PD 1·36 (SEM 0·227) mV; I(sc) 22·4 (SEM 2·24) μA/cm(2)). Intestinal tissue from control, but not from Gln-supplemented, animals responded to E. coli with a significant increase in mucosal cytokine mRNA (IL-1β, IL-6, transforming growth factor-β and IL-10). Tight-junction protein expression (claudin-1 and occludin) was reduced with exposure to E. coli in control-fed animals and was not influenced in Gln-supplemented piglets. Gln supplementation may be useful in reducing the severity of weaning-related gastrointestinal infections, by reducing the mucosal cytokine response and altering intestinal barrier function.

Principles of Chromosome Architecture Revealed by Hi-C.

PubMed

Eagen, Kyle P

2018-06-01

Chromosomes are folded and compacted in interphase nuclei, but the molecular basis of this folding is poorly understood. Chromosome conformation capture methods, such as Hi-C, combine chemical crosslinking of chromatin with fragmentation, DNA ligation, and high-throughput DNA sequencing to detect neighboring loci genome-wide. Hi-C has revealed the segregation of chromatin into active and inactive compartments and the folding of DNA into self-associating domains and loops. Depletion of CTCF, cohesin, or cohesin-associated proteins was recently shown to affect the majority of domains and loops in a manner that is consistent with a model of DNA folding through extrusion of chromatin loops. Compartmentation was not dependent on CTCF or cohesin. Hi-C contact maps represent the superimposition of CTCF/cohesin-dependent and -independent folding states. Copyright © 2018 Elsevier Ltd. All rights reserved.

Steatorrhoea in rats with an intestinal cul-de-sac

PubMed Central

Hoet, P. P.; Eyssen, H.

1964-01-01

Steatorrhoea in rats with an intestinal cul-de-sac is mainly due to malabsorption of alimentary fats but faecal lipids of endogenous origin are also increased. Steatorrhoea depends on the site of the blind loop in the small intestine and is mainly caused by bacterial proliferation in the lumen of the gut. The aetiological role of Gram-positive anaerobic microbes, especially Clostridium welchii, is suggested. ImagesFIG. 3FIG. 4FIG. 5FIG. 6 PMID:14209913

Hemodynamic and permeability characteristics of acute experimental necrotizing enterocolitis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, M.J.; Adams, J.; Gu, X.A.

1990-10-01

We examined the local hemodynamic response of intestinal loops during acute necrotizing enterocolitis (NEC) in anesthetized rabbits. NEC was induced in ileal loops by transmural injection of a solution containing casein (10 mg/ml) and calcium gluconate (50 mg/ml) acidified to pH 4.0 with propionic or acetic acid. Control loops received casein only (pH 5.0). Mucosal damage was quantified by the blood-to-lumen movement of (51Cr)EDTA, fluid shifts into the lumen, and histology. Mean arterial pressure and loop blood flow were steady over the 3-hr period, loop fluid volume decreased, and there was no evidence of necrosis or epithelial damage. In loopsmore » receiving acidified casein and calcium gluconate, there was an immediate dramatic increase in loop blood flow that returned to baseline by 50 min. In addition, loop fluid volume was dramatically increased, necrosis was noted in the form of blunting and loss of villi, and sevenfold increase in (51Cr)EDTA permeability was evident. Administration of CV 1808 (30 mg/kg/hr), a selective adenosine2 agonist, which maintained and elevated loop blood flow throughout the 3 hr protocol, failed to alter the changes in loop fluid volume or prevent necrosis. Histamine levels in loop fluid levels were significantly elevated 20-30 min after NEC induction when compared to saline controls, indicating an early activation of mucosal defenses with this luminal insult. Thus, this model of NEC is characterized by a transient, acute hyperemia, increased intestinal permeability, and histamine release. As mucosal damage was independent of ischemia and could not be prevented by vasodilatory therapy, this model supports the clinical findings that NEC is correlated with luminal factors related to feeding and independent of cardiovascular stress.« less

Method for creating ideal tissue fusion in soft-tissue structures using radio frequency (RF) energy.

PubMed

Shields, Chelsea A; Schechter, David A; Tetzlaff, Phillip; Baily, Ali L; Dycus, Sean; Cosgriff, Ned

2004-01-01

Bipolar radiofrequency (RF) energy can successfully seal vascular structures up to 7 mm by fusing collagen and elastin in the lumen. Valleylab has created a system to expand this technology beyond vessel sealing with the development of a closed-loop, feedback-control RF generator that closely monitors tissue fusion. This generator, operating with a loop time of approximately 250 micros, continuously adjusts energy output, creating optimized soft-tissue fusion through structural protein amalgamation. In the first study, RF energy was applied to canine lung using the new-generation generator and lung-prototype device. A lobectomy was completed, sealing the lobar bronchus, parenchyma, and pulmonary vasculature. Chronic performance of the seals was evaluated at necropsy on postoperative days 7 and 14. In a second study, RF energy was applied to porcine small intestine using the same closed-loop generator and anastomosis prototype device. Acute tissue fusion was assessed qualitatively for hemostasis and seal quality. Terminal tissue evaluation was completed on postoperative day 7 and analyzed histopathologically. Histopathology confirmed acute and chronic tissue fusion in both the lung and intestine. Normal pathological healing was substantiated by angiogenesis, granulation, and proliferation of fibroblasts. Preliminary studies using canine lung and porcine small intestine demonstrate the potential of this closed-loop generator for soft-tissue amalgamation. Advanced monitoring capabilities make this fusion system applicable in many soft-tissue structures with adequate collagen and elastin. Further investigation of potential surgical applications needs to be completed.

Meckel's diverticulum incarcerated in a transmesocolic internal hernia

PubMed Central

Wu, Si-Yuan; Ho, Meng-Hsing; Hsu, Sheng-Der

2014-01-01

Intestinal obstruction is a common complication associated with Meckel’s diverticulum in adults. The diverticulum itself or its fibrous band can lead to an intestinal volvulus, intussusceptions, or closed-loop obstructions, which require surgery. The incarceration of Meckel’s diverticulum in either inguinal or femoral hernia sacs (Littre’s hernia) is another, less common, etiology underlying intestinal obstruction. This case report describes a 45-year-old man who had an obstruction associated with a Meckel’s diverticulum that passed through a congenital defect in the mesocolon into the right subphrenic space. The patient, who had not undergone abdominal surgery previously, came to the emergency room with acute onset of intermittent epigastric pain and abdominal distention. Computed tomography images showed the presence of a segment of the small bowel and a diverticulum in the right subphrenic space and paracolic gutter. The twisted mesentery and the dilated loops of the proximal small bowel were indicative of an intestinal volvulus and obstruction. Meckel’s diverticulum complicated by a transmesocolic internal hernia was diagnosed, and this condition was confirmed during emergency surgery. The patient’s postoperative recovery was uneventful. This case report highlights another presentation of Meckel’s diverticulum, that is, in combination with a transmesocolic internal hernia. This etiology may lead to an intestinal volvulus and necessitate early surgery. PMID:25309093

Positive Regulatory Control Loop between Gut Leptin and Intestinal GLUT2/GLUT5 Transporters Links to Hepatic Metabolic Functions in Rodents

PubMed Central

Sakar, Yassine; Nazaret, Corinne; Lettéron, Philippe; Ait Omar, Amal; Avenati, Mathilde; Viollet, Benoît; Ducroc, Robert; Bado, André

2009-01-01

Background and Aims The small intestine is the major site of absorption of dietary sugars. The rate at which they enter and exit the intestine has a major effect on blood glucose homeostasis. In this study, we determine the effects of luminal leptin on activity/expression of GLUT2 and GLUT5 transporters in response to sugars intake and analyse their physiological consequences. Methodology Wistar rats, wild type and AMPKα2 −/− mice were used. In vitro and in vivo isolated jejunal loops were used to quantify transport of fructose and galactose in the absence and the presence of leptin. The effects of fructose and galactose on gastric leptin release were determined. The effects of leptin given orally without or with fructose were determined on the expression of GLUT2/5, on some gluconeogenesis and lipogenic enzymes in the intestine and the liver. Principal Findings First, in vitro luminal leptin activating its receptors coupled to PKCβII and AMPKα, increased insertion of GLUT2/5 into the brush-border membrane leading to enhanced galactose and fructose transport. Second in vivo, oral fructose but not galactose induced in mice a rapid and potent release of gastric leptin in gastric juice without significant changes in plasma leptin levels. Moreover, leptin given orally at a dose reproducing comparable levels to those induced by fructose, stimulated GLUT5-fructose transport, and potentiated fructose-induced: i) increase in blood glucose and mRNA levels of key gluconeogenesis enzymes; ii) increase in blood triglycerides and reduction of mRNA levels of intestinal and hepatic Fasting-induced adipocyte factor (Fiaf) and iii) increase in SREBP-1c, ACC-1, FAS mRNA levels and dephosphorylation/activation of ACC-1 in liver. Conclusion/Significance These data identify for the first time a positive regulatory control loop between gut leptin and fructose in which fructose triggers release of gastric leptin which, in turn, up-regulates GLUT5 and concurrently modulates metabolic functions in the liver. This loop appears to be a new mechanism (possibly pathogenic) by which fructose consumption rapidly becomes highly lipogenic and deleterious. PMID:19956534

Effect of γ-Cyclodextrin Inclusion Complex on the Absorption of R-α-Lipoic Acid in Rats

PubMed Central

Uchida, Ryota; Iwamoto, Kosuke; Nagayama, Suetada; Miyajima, Atsushi; Okamoto, Hinako; Ikuta, Naoko; Fukumi, Hiroshi; Terao, Keiji; Hirota, Takashi

2015-01-01

R-α-lipoic acid (RLA) is an endogenous organic acid, and works as a cofactor for mitochondrial enzymes and as a kind of antioxidant. Inclusion complexes of RLA with α-, β- or γ-cyclodextrins (CD) were prepared and orally administered as a suspension to rats. Among them, RLA/γ-CD showed the highest plasma exposure, and its area under the plasma concentration-time curve (AUC) of RLA was 2.2 times higher than that after oral administration of non-inclusion RLA. On the other hand, the AUC after oral administration of non-inclusion RLA and RLA/γ-CD to pylorus-ligated rats did not differ. However, the AUC after intraduodenal administration of RLA/γ-CD was 5.1 times higher than that of non-inclusion RLA, and was almost comparable to the AUC after intraduodenal administration of RLA-Na solution. Furthermore, the AUC after intraduodenal administration of RLA/γ-CD was not affected by biliary ligation or co-administration of an amylase inhibitor. These findings demonstrated that RLA was absorbed from the small intestine effectively when orally administered as a γ-CD inclusion complex, which could be easily dissolved in the lumen of the intestine. In conclusion, γ-CD inclusion complex is an appropriate formulation for supplying RLA as a drug or nutritional supplement with respect to absorption. PMID:25946345

Trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife: A pilot animal study

PubMed Central

Jiang, Sheng-Jun; Shi, Hong; Swar, Gyanendra; Wang, Hai-Xia; Liu, Xiao-Jing; Wang, Yong-Guang

2013-01-01

AIM: To investigate the feasibility and safety of Natural orifice trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife in a non-survival porcine model. METHODS: Pure natural orifice transluminal endoscopic surgery (NOTES) cholecystectomy was performed on three non-survival pigs, by transumbilical approach, using a water-jet hybrid-knife. Under general anesthesia, the following steps detailed the procedure: (1) incision of the umbilicus followed by the passage of a double-channel flexible endsocope through an overtube into the peritoneal cavity; (2) establishment of pneumoperitoneum; (3) abdominal exploration; (4) endoscopic cholecystectomy: dissection of the gallbladder performed using water jet equipment, ligation of the cystic artery and duct conducted using nylon loops; and (5) necropsy with macroscopic evaluation. RESULTS: Transumbilical endoscopic cholecystectomy was successfully completed in the first and third pig, with minor bleedings. The dissection times were 137 and 42 min, respectively. The total operation times were 167 and 69 min, respectively. And the lengths of resected specimen were 6.5 and 6.1 cm, respectively. Instillation of the fluid into the gallbladder bed produced edematous, distended tissue making separation safe and easy. Reliable ligation using double nylon loops insured the safety of cutting between the loops. There were no intraoperative complications or hemodynamic instability. Uncontrolled introperative bleeding occurred in the second case, leading to the operation failure. CONCLUSION: Pure NOTES trans-umbilical cholecystectomy with a water-jet hybrid-knife appears to be feasible and safe. Further investigation of this technique with long-term follow-up in animals is needed to confirm the preliminary observation. PMID:24187461

Trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife: a pilot animal study.

PubMed

Jiang, Sheng-Jun; Shi, Hong; Swar, Gyanendra; Wang, Hai-Xia; Liu, Xiao-Jing; Wang, Yong-Guang

2013-10-28

To investigate the feasibility and safety of Natural orifice trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife in a non-survival porcine model. Pure natural orifice transluminal endoscopic surgery (NOTES) cholecystectomy was performed on three non-survival pigs, by transumbilical approach, using a water-jet hybrid-knife. Under general anesthesia, the following steps detailed the procedure: (1) incision of the umbilicus followed by the passage of a double-channel flexible endoscope through an overtube into the peritoneal cavity; (2) establishment of pneumoperitoneum; (3) abdominal exploration; (4) endoscopic cholecystectomy: dissection of the gallbladder performed using water jet equipment, ligation of the cystic artery and duct conducted using nylon loops; and (5) necropsy with macroscopic evaluation. Transumbilical endoscopic cholecystectomy was successfully completed in the first and third pig, with minor bleedings. The dissection times were 137 and 42 min, respectively. The total operation times were 167 and 69 min, respectively. And the lengths of resected specimen were 6.5 and 6.1 cm, respectively. Instillation of the fluid into the gallbladder bed produced edematous, distended tissue making separation safe and easy. Reliable ligation using double nylon loops insured the safety of cutting between the loops. There were no intraoperative complications or hemodynamic instability. Uncontrolled introperative bleeding occurred in the second case, leading to the operation failure. Pure NOTES trans-umbilical cholecystectomy with a water-jet hybrid-knife appears to be feasible and safe. Further investigation of this technique with long-term follow-up in animals is needed to confirm the preliminary observation.

A girl with spina bifida, an extra leg, and ectopic intestinal loops--a "foetus in foetu" or a whim of the neural crest?

PubMed

Lende, G; Wendemu, W; Mørk, S; Wester, K

2007-10-01

This article describes a girl with an extra leg attached to her lower back, combined with a spina bifida and a myelomeningocele. Despite lacking sensory or motor functions, the leg grew proportionately with the rest of the body. The bony structures were almost normal. A cross section showed fat tissue with some centrally situated blood vessels, nerve bundles, and muscular fragments. Proximally, an isolated colon loop was found. The extra leg and intestine respected the dorsal fascia, without connection with the peritoneal or retroperitoneal compartments. The finding is discussed with reference to existing hypotheses for limb formation.

Positive selection of the peripheral B cell repertoire in gut-associated lymphoid tissues

PubMed Central

Rhee, Ki-Jong; Jasper, Paul J.; Sethupathi, Periannan; Shanmugam, Malathy; Lanning, Dennis; Knight, Katherine L.

2005-01-01

Gut-associated lymphoid tissues (GALTs) interact with intestinal microflora to drive GALT development and diversify the primary antibody repertoire; however, the molecular mechanisms that link these events remain elusive. Alicia rabbits provide an excellent model to investigate the relationship between GALT, intestinal microflora, and modulation of the antibody repertoire. Most B cells in neonatal Alicia rabbits express VHn allotype immunoglobulin (Ig)M. Within weeks, the number of VHn B cells decreases, whereas VHa allotype B cells increase in number and become predominant. We hypothesized that the repertoire shift from VHn to VHa B cells results from interactions between GALT and intestinal microflora. To test this hypothesis, we surgically removed organized GALT from newborn Alicia pups and ligated the appendix to sequester it from intestinal microflora. Flow cytometry and nucleotide sequence analyses revealed that the VHn to VHa repertoire shift did not occur, demonstrating the requirement for interactions between GALT and intestinal microflora in the selective expansion of VHa B cells. By comparing amino acid sequences of VHn and VHa Ig, we identified a putative VH ligand binding site for a bacterial or endogenous B cell superantigen. We propose that interaction of such a superantigen with VHa B cells results in their selective expansion. PMID:15623575

Post-cholecystectomy biliary injuries: one center experience.

PubMed

Fathy, Omar; Wahab, Mohamed Abdel; Hamdy, Emad; Elshoubary, Mohamed; Kandiel, Tharwat; Elraof, Ahmad Abd; Elhemaly, Mohamed; Salah, Tarek; Elhanafy, Ehab; Atef, Ehab; Sultan, Ahmad Mohamed; Elebiedy, Gamal; Anwar, Nabieh; Sultan, Ahmad

2011-01-01

Post-cholecystectomy bile duct injuries (BDIs) represent a challenge in diagnosis and management. From March 1995 to August 2009, 274 patients with post-cholecystectomy BDIs were managed at our center. All patients were subjected to laboratory tests, sonography, ERCP and MRCP. The management varied according to the type of injury. Seventy-one (25.9%) LC and 203 (74.1%) OC were performed; 8(2.9%) were detected intraoperatively; 270 patients were referred from other hospitals. From those discovered intraoperatively, 7 had hepatico-jejunostomy and one died from severe peritonitis; 11 (4%) presented with generalized and 112 (40.9%) with localized peritonitis. The leak site was the cystic duct (57 cases), accessory duct in the liver bed (5 cases), right hepatic duct (4 cases) and lateral tear in the CBD (12 cases). Endoscopic stenting was performed for all of them. The remaining 34 patients had a completely ligated distal duct and therefore had hepatico-jejunostomy Roux loop; 143 patients (52.2%) presented with early (79 cases) and late (64 cases) jaundice; 126 cases had hepatico-jejunostomy. The remaining 17 patients were treated by balloon dilatation. Endoscopic stenting can manage cases with cystic or accessory duct leak while, hepatico-jejunostomy Roux loop represents the golden procedure for management of transected or ligated CBD.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagino, Ko; Yokozawa, Junji; Sasaki, Yu

Highlights: Black-Right-Pointing-Pointer Insulin secretion was increased during the OGTT or IVGTT in mesenteric lymph duct-ligated rats. Black-Right-Pointing-Pointer Proliferation of islet {beta}-cells was upregulated in lymph duct-ligated rats. Black-Right-Pointing-Pointer Mesenteric lymph duct flow has a role in glucose metabolism. -- Abstract: Background and aims: It has been suggested that intestinal lymph flow plays an important role in insulin secretion and glucose metabolism after meals. In this study, we investigated the influence of ligation of the mesenteric lymph duct on glucose metabolism and islet {beta}-cells in rats. Methods: Male Sprague-Dawley rats (10 weeks old) were divided into two groups: one underwent ligationmore » of the mesenteric lymph duct above the cistern (ligation group), and the other underwent a sham operation (sham group). After 1 and 2 weeks, fasting plasma concentrations of glucose, insulin, triglyceride, glucose-dependent insulinotropic polypeptide (GIP), and the active form of glucagon-like peptide-1 (GLP-1) were measured. At 2 weeks after the operation, the oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT) were performed. After the rats had been sacrificed, the insulin content of the pancreas was measured and the proliferation of {beta}-cells was assessed immunohistochemically using antibodies against insulin and Ki-67. Results: During the OGTT, the ligation group showed a significant decrease in the plasma glucose concentration at 120 min (p < 0.05) and a significant increase in the plasma insulin concentration by more than 2-fold at 15 min (p < 0.01). On the other hand, the plasma GIP concentration was significantly decreased at 60 min (p < 0.01) in the ligated group, while the active form of GLP-1 showed a significantly higher level at 90 min (1.7-fold; p < 0.05) and 120 min (2.5-fold; p < 0.01). During the IVGTT, the plasma insulin concentration in the ligation group was significantly higher at 2 min (more than 1.4-fold; p < 0.05). Immunohistochemistry showed that the ratios of {beta}-cell area/acinar cell area and {beta}-cell area/islet area, and also {beta}-cell proliferation, were significantly higher in the ligation group than in the sham group (p < 0.05, p < 0.01 and p < 0.01, respectively). The insulin content per unit wet weight of pancreas was also significantly increased in the ligation group (p < 0.05). Conclusions: In rats with ligation of the mesenteric lymph duct, insulin secretion during the OGTT or IVGTT was higher, and the insulin content and {beta}-cell proliferation in the pancreas were also increased. Our data show that mesenteric lymph duct flow has a role in glucose metabolism.« less

The synergistic necrohemorrhagic action of Clostridium perfringens perfringolysin and alpha toxin in the bovine intestine and against bovine endothelial cells

PubMed Central

2013-01-01

Bovine necrohemorrhagic enteritis is a major cause of mortality in veal calves. Clostridium perfringens is considered as the causative agent, but there has been controversy on the toxins responsible for the disease. Recently, it has been demonstrated that a variety of C. perfringens type A strains can induce necrohemorrhagic lesions in a calf intestinal loop assay. These results put forward alpha toxin and perfringolysin as potential causative toxins, since both are produced by all C. perfringens type A strains. The importance of perfringolysin in the pathogenesis of bovine necrohemorrhagic enteritis has not been studied before. Therefore, the objective of the current study was to evaluate the role of perfringolysin in the development of necrohemorrhagic enteritis lesions in calves and its synergism with alpha toxin. A perfringolysin-deficient mutant, an alpha toxin-deficient mutant and a perfringolysin alpha toxin double mutant were less able to induce necrosis in a calf intestinal loop assay as compared to the wild-type strain. Only complementation with both toxins could restore the activity to that of the wild-type. In addition, perfringolysin and alpha toxin had a synergistic cytotoxic effect on bovine endothelial cells. This endothelial cell damage potentially explains why capillary hemorrhages are an initial step in the development of bovine necrohemorrhagic enteritis. Taken together, our results show that perfringolysin acts synergistically with alpha toxin in the development of necrohemorrhagic enteritis in a calf intestinal loop model and we hypothesize that both toxins act by targeting the endothelial cells. PMID:23782465

Protective effect of aged garlic extract on the small intestinal damage of rats induced by methotrexate administration.

PubMed

Horie, T; Matsumoto, H; Kasagi, M; Sugiyama, A; Kikuchi, M; Karasawa, C; Awazu, S; Itakura, Y; Fuwa, T

1999-08-01

The methotrexate (MTX) administration to rats causes the damage of small intestine. The small intestinal damage was evaluated by measuring the intestinal permeability of the poorly absorbable compound, fluorescein isothiocyanate (FITC)-labeled dextran (average molecular weight, 4,400) (FD-4) using the in vitro everted intestine technique and by determining the FD-4 that appeared in plasma using the in situ closed loop intestine technique. The MTX administration to rats fed with the standard laboratory diet increased the small intestinal permeability of FD-4 due to the damage of the small intestine. Interestingly, the permeability of FD-4, when MTX was administered to rats fed with the aged garlic extract containing diet, was depressed almost to the level of control rats without the MTX treatment. The present study showed that the aged garlic extract protected the small intestine from the damage induced by the action of MTX on the crypt cells.

Alleviation by garlic of antitumor drug-induced damage to the intestine.

PubMed

Horie, T; Awazu, S; Itakura, Y; Fuwa, T

2001-03-01

Antitumour drugs such as methotrexate (MTX) and 5-fluorouracil (5-FU) induce intestinal damage. This is a serious side effect of cancer chemotherapy. The present studies examined whether or not aged garlic extract (AGE) protects against damage from these antitumor drugs. Both drugs were administered orally for 4 or 5 d to rats fed a standard laboratory diet with and without 2% AGE. The small intestinal absorption of the poorly absorbable compound, fluorescein isothiocyanate--labeled dextran (FD-4; average molecular weight, 4400) was used to evaluate the damage to the intestine using the in vitro everted intestine technique and the in situ intestinal loop technique. FD-4 absorption increased in the antitumour drug-treated rats fed the diet without garlic. Interestingly, FD-4 absorption was depressed in rats fed the diet containing AGE. These results suggest that AGE may protect the small intestine of rats from antitumour drug-induced damage.

Blind Loop Syndrome

MedlinePlus

... be caused by: Complications of abdominal surgery, including gastric bypass for obesity and gastrectomy to treat peptic ulcers and stomach cancer Structural problems in and around your small intestine, ...

[Effect of somatostatin-14 in simple mechanical obstruction of the small intestine].

PubMed

Jimenez-Garcia, A; Ahmad Araji, O; Balongo Garcia, R; Nogales Munoz, A; Salguero Villadiego, M; Cantillana Martinez, J

1994-02-01

In order to investigate the properties of somatostatin-14 we studied an experimental model of simple mechanical and closed loop occlusion. Forty-eight New Zealand rabbits were assigned randomly to three groups of 16: group C (controls) was operated and treated with saline solution (4 cc/Kg/h); group A was operated and initially treated with saline solution and an equal dose of somatostatin-14 (3.5 micrograms/Kg/h; and group B was operated and treated in the same manner as group A, but later, 8 hours after the laparotomy. The animals were sacrificed 24 hours later; intestinal secretion was quantified, blood and intestinal fluid chemistries were performed and specimens of the intestine were prepared for histological examination. Descriptive statistical analysis of the results was performed with the ANOVA, a semi-quantitative test and the covariance test. Somatostatin-14 produced an improvement in the volume of intestinal secretion in the treated groups compared with the control group. The results were statistically significant in group B treated after an 8-hour delay: closed loop (ml): 6.40 +/- 1.12, 2.50 +/- 0.94, 1.85 +/- 0.83 and simple mechanical occlusion (ml): 175 +/- 33.05, 89.50 +/- 9.27, 57.18 +/- 21.23, p < 0.01 for groups C, A and B C, A and B respectively. Net secretion of Cl and Na ions was also improved, p < 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)

A Case of 2-Year-Old Child with Entero-Enteric Fistula Following Ingestion of 25 Magnets.

PubMed

Pogorelić, Zenon; Borić, Matija; Markić, Joško; Jukić, Miro; Grandić, Leo

Magnet ingestion usually does not cause serious complications, but in case of multiple magnet ingestion or ingestion of magnet with other metal it could cause intestinal obstruction, fistula formation or even perforation. We report case of intestinal obstruction and fistula formation following ingestion of 25 magnets in a 2-year-old girl. Intraoperatively omega shaped intestinal loop with fistula caused by two magnetic balls was found. Intestine trapped with magnetic balls was edematous and inflamed. Resection of intestinal segment was performed, followed by entero-enteric anastomosis. A total of 25 magnets were removed from resected intestine. Single magnet ingestion is treated as non-magnetic foreign body. Multiple magnet ingestion should be closely monitored and surgical approach could be the best option to prevent or to cure its complications.

Replication stress induces accumulation of FANCD2 at central region of large fragile genes

PubMed Central

Okamoto, Yusuke; Iwasaki, Watal M; Kugou, Kazuto; Takahashi, Kazuki K; Oda, Arisa; Sato, Koichi; Kobayashi, Wataru; Kawai, Hidehiko; Sakasai, Ryo; Takaori-Kondo, Akifumi; Yamamoto, Takashi; Kanemaki, Masato T; Taoka, Masato; Isobe, Toshiaki; Kurumizaka, Hitoshi; Innan, Hideki; Ohta, Kunihiro; Ishiai, Masamichi; Takata, Minoru

2018-01-01

Abstract During mild replication stress provoked by low dose aphidicolin (APH) treatment, the key Fanconi anemia protein FANCD2 accumulates on common fragile sites, observed as sister foci, and protects genome stability. To gain further insights into FANCD2 function and its regulatory mechanisms, we examined the genome-wide chromatin localization of FANCD2 in this setting by ChIP-seq analysis. We found that FANCD2 mostly accumulates in the central regions of a set of large transcribed genes that were extensively overlapped with known CFS. Consistent with previous studies, we found that this FANCD2 retention is R-loop-dependent. However, FANCD2 monoubiquitination and RPA foci formation were still induced in cells depleted of R-loops. Interestingly, we detected increased Proximal Ligation Assay dots between FANCD2 and R-loops following APH treatment, which was suppressed by transcriptional inhibition. Collectively, our data suggested that R-loops are required to retain FANCD2 in chromatin at the middle intronic region of large genes, while the replication stress-induced upstream events leading to the FA pathway activation are not triggered by R-loops. PMID:29394375

The reaction time of organ-forming substance in goldfish EGG and its relationship with mesodermal formation

NASA Astrophysics Data System (ADS)

Zhang, Shicui; Wu, Shangqin

1988-12-01

Fertilized goldfish eggs were dechorionated with a pair of forceps and were cut off along or a little above the equator into animal and vegetative parts at desired stages with a glass needle or ligated into two connected fragments before cleavage with baby hair loop. Some of the ligated eggs were detached by further fastening soon after ligation, and some released later at different stages (2-cell, 16-cell, 128-cell, 512-cell, mid-blastula) to let the organ-forming substance (OFS) enter the blastoderm. The cholinesterase (ChE) in the resulting embryos was assayed. The results are as follows. 1. All the 142 embryos developed from the animal hemispheres cut off or ligated off before cleavage gave rise to hyperblastula in which no ChE activity was observed. 2. All 50 embryos obtained from animal halves isolated at the 8-cell stage produced ChE. 3. Embryos developed from the eggs released before the 512-cell stage formed ChE, but the later the releasing of the hair knots, the smaller the number of ChE-producing embryos. 4. After the 512-cell stage (excluding this stage), neither ChE nor tissue differentiation occurred in the embryos developed from the unfastened eggs though their OFS flow was set free. Since ChE is thought to be a muscle-specific enzyme in the early developmental stage, it is concluded that the OFS in goldfish egg appears to be indispensable for the establishment of the mesoderm.

Influence of fentanyl and morphine on intestinal circulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tverskoy, M.; Gelman, S.; Fowler, K.C.

The influence of fentanyl and morphine on the intestinal circulation was evaluated in an isolated loop preparation in 37 dogs anesthetized with pentobarbital intravenously. Selected intestinal segments were pumped with aortic blood at a constant pressure of 100 mm Hg. A mixture of /sup 86/Rb and 9-micron spheres labeled with /sup 141/Ce was injected into the arterial cannula supplying the intestinal loop, while mesenteric venous blood was collected for activity counting. A strong correlation was found between the clearances of rubidium and microspheres (r = 0.97, P less than 0.0001), suggesting that the shunting of 9-micron spheres through the intestinesmore » reflects the shunting of blood through nonnutritive vessels. Intravenous fentanyl decreased oxygen uptake (O/sub 2/up), and vascular resistance (VR), and increased blood flow (BF), rubidium and microsphere clearances (Cl-Rb, Cl-Sph, respectively), and permeability--surface area product (PS) in a dose-related fashion. Intravenous morphine in a dose of 1 mg X kg-1 increased Cl-Rb (nutritive BF) without changes in total (nutritive and nonnutritive) BF. This increase in nutritive BF is probably related to morphine-induced histamine release. Morphine in a dose of 5 mg X kg-1 was accompanied by vasoconstriction that was completely abolished by alpha-adrenoceptor blockade. The data suggest that morphine-induced intestinal vasoconstriction is mediated via a release of epinephrine, apparently from the adrenal medulla. It is concluded that changes in the intestinal circulation during anesthesia with narcotics might play a certain role in the cardiovascular homeostasis during anesthesia and surgery. An increase in oxygen content in portal venous blood, resulting from a decrease in intestinal oxygen uptake, should facilitate hepatic oxygenation.« less

Intra-abdominal infection combined with intra-abdominal hypertension aggravates the intestinal mucosal barrier dysfunction.

PubMed

Li, Yuan; Ren, Jianan; Wu, Xiuwen; Li, Jieshou

2018-02-28

Some patients with intra-abdominal infection (IAI) may develop intra-abdominal hypertension (IAH) during treatment. The present study investigated the impact of IAI combined with IAH on the intestinal mucosal barrier in a rabbit model. Forty-eight New Zealand white rabbits were randomly divided into four groups: (i) IAI and IAH; (ii) IAI alone; (iii) IAH alone; and (iv) Control group. IAI model: cecal ligation and puncture for 48 h; IAH model: raised intra-abdominal pressure (IAP) of 20 mmHg for 4 h. Pathological changes in intestinal mucosa were confirmed by light and scanning electron microscopy. FITC-conjugated dextran (FITC-dextran) by gavage was used to measure intestinal mucosal permeability in plasma. Endotoxin, d-Lactate, and diamine oxidase (DAO) in plasma were measured to determine intestinal mucosal damage. Malonaldehyde (MDA), superoxide dismutase (SOD), and GSH in ileum tissues were measured to evaluate intestinal mucosal oxidation and reducing state. Histopathologic scores were significantly higher in the IAI and IAH group, followed by IAI alone, IAH alone, and the control group. FITC-dextran, d-Lactate, DAO, and endotoxin in plasma and MDA in ileum tissues had similar trends. GSH and SOD were significantly lowest the in IAI and IAH group. Occludin levels were lowest in the ileums of the IAI and IAH group. All differences were statistically significant ( P -values <0.001). IAI combined with IAH aggravates damage of the intestinal mucosal barrier in a rabbit model. The combined effects were significantly more severe compared with a single factor. IAI combined with IAH should be prevented and treated effectively. © 2018 The Author(s).

Comparative quantification of human intestinal bacteria based on cPCR and LDR/LCR

PubMed Central

Tang, Zhou-Rui; Li, Kai; Zhou, Yu-Xun; Xiao, Zhen-Xian; Xiao, Jun-Hua; Huang, Rui; Gu, Guo-Hao

2012-01-01

AIM: To establish a multiple detection method based on comparative polymerase chain reaction (cPCR) and ligase detection reaction (LDR)/ligase chain reaction (LCR) to quantify the intestinal bacterial components. METHODS: Comparative quantification of 16S rDNAs from different intestinal bacterial components was used to quantify multiple intestinal bacteria. The 16S rDNAs of different bacteria were amplified simultaneously by cPCR. The LDR/LCR was examined to actualize the genotyping and quantification. Two beneficial (Bifidobacterium, Lactobacillus) and three conditionally pathogenic bacteria (Enterococcus, Enterobacterium and Eubacterium) were used in this detection. With cloned standard bacterial 16S rDNAs, standard curves were prepared to validate the quantitative relations between the ratio of original concentrations of two templates and the ratio of the fluorescence signals of their final ligation products. The internal controls were added to monitor the whole detection flow. The quantity ratio between two bacteria was tested. RESULTS: cPCR and LDR revealed obvious linear correlations with standard DNAs, but cPCR and LCR did not. In the sample test, the distributions of the quantity ratio between each two bacterial species were obtained. There were significant differences among these distributions in the total samples. But these distributions of quantity ratio of each two bacteria remained stable among groups divided by age or sex. CONCLUSION: The detection method in this study can be used to conduct multiple intestinal bacteria genotyping and quantification, and to monitor the human intestinal health status as well. PMID:22294830

Comparative quantification of human intestinal bacteria based on cPCR and LDR/LCR.

PubMed

Tang, Zhou-Rui; Li, Kai; Zhou, Yu-Xun; Xiao, Zhen-Xian; Xiao, Jun-Hua; Huang, Rui; Gu, Guo-Hao

2012-01-21

To establish a multiple detection method based on comparative polymerase chain reaction (cPCR) and ligase detection reaction (LDR)/ligase chain reaction (LCR) to quantify the intestinal bacterial components. Comparative quantification of 16S rDNAs from different intestinal bacterial components was used to quantify multiple intestinal bacteria. The 16S rDNAs of different bacteria were amplified simultaneously by cPCR. The LDR/LCR was examined to actualize the genotyping and quantification. Two beneficial (Bifidobacterium, Lactobacillus) and three conditionally pathogenic bacteria (Enterococcus, Enterobacterium and Eubacterium) were used in this detection. With cloned standard bacterial 16S rDNAs, standard curves were prepared to validate the quantitative relations between the ratio of original concentrations of two templates and the ratio of the fluorescence signals of their final ligation products. The internal controls were added to monitor the whole detection flow. The quantity ratio between two bacteria was tested. cPCR and LDR revealed obvious linear correlations with standard DNAs, but cPCR and LCR did not. In the sample test, the distributions of the quantity ratio between each two bacterial species were obtained. There were significant differences among these distributions in the total samples. But these distributions of quantity ratio of each two bacteria remained stable among groups divided by age or sex. The detection method in this study can be used to conduct multiple intestinal bacteria genotyping and quantification, and to monitor the human intestinal health status as well.

Animal experimental studies using small intestine endoscope

PubMed Central

Liu, Jin-Hua; Liu, Dan-Yang; Wang, Li; Han, Li-Ping; Qi, Zhe-Yu; Ren, Hai-Jun; Feng, Yan; Luan, Feng-Ming; Mi, Liang-Tian; Shan, Shu-Mei

2017-01-01

AIM To assess the feasibility and safety of a novel enteroscope, negative-pressure suction endoscope in examining the small intestine of a porcine model. METHODS In vitro experiments in small intestinal loops from 20 pigs and in vivo experiments in 20 living pigs were conducted. RESULTS In in vitro experiments, a negative pressure of > 0.06 MPa was necessary for optimal visualization of the intestine, and this pressure did not cause gross or histological damage to the mucosa. For satisfactory examination of the small intestine in vivo, higher negative pressure (> 1.00 MPa) was required. Despite this higher pressure, the small intestine did not show any gross or microscopic damage in the suctioned areas. The average time of examination in the living animals was 60 ± 7.67 min. The animals did not experience any apparent ill effects from the procedure. CONCLUSION Small intestine endoscope was safely performed within a reasonable time period and enabled complete visualization of the intestine in most cases. PMID:28611521

Enterocyte-specific epidermal growth factor prevents barrier dysfunction and improves mortality in murine peritonitis.

PubMed

Clark, Jessica A; Gan, Heng; Samocha, Alexandr J; Fox, Amy C; Buchman, Timothy G; Coopersmith, Craig M

2009-09-01

Systemic administration of epidermal growth factor (EGF) decreases mortality in a murine model of septic peritonitis. Although EGF can have direct healing effects on the intestinal mucosa, it is unknown whether the benefits of systemic EGF in peritonitis are mediated through the intestine. Here, we demonstrate that enterocyte-specific overexpression of EGF is sufficient to prevent intestinal barrier dysfunction and improve survival in peritonitis. Transgenic FVB/N mice that overexpress EGF exclusively in enterocytes (IFABP-EGF) and wild-type (WT) mice were subjected to either sham laparotomy or cecal ligation and puncture (CLP). Intestinal permeability, expression of the tight junction proteins claudins-1, -2, -3, -4, -5, -7, and -8, occludin, and zonula occludens-1; villus length; intestinal epithelial proliferation; and epithelial apoptosis were evaluated. A separate cohort of mice was followed for survival. Peritonitis induced a threefold increase in intestinal permeability in WT mice. This was associated with increased claudin-2 expression and a change in subcellular localization. Permeability decreased to basal levels in IFABP-EGF septic mice, and claudin-2 expression and localization were similar to those of sham animals. Claudin-4 expression was decreased following CLP but was not different between WT septic mice and IFABP-EGF septic mice. Peritonitis-induced decreases in villus length and proliferation and increases in apoptosis seen in WT septic mice did not occur in IFABP-EGF septic mice. IFABP-EGF mice had improved 7-day mortality compared with WT septic mice (6% vs. 64%). Since enterocyte-specific overexpression of EGF is sufficient to prevent peritonitis-induced intestinal barrier dysfunction and confers a survival advantage, the protective effects of systemic EGF in septic peritonitis appear to be mediated in an intestine-specific fashion.

Attenuated portal hypertension in germ-free mice: Function of bacterial flora on the development of mesenteric lymphatic and blood vessels.

PubMed

Moghadamrad, Sheida; McCoy, Kathy D; Geuking, Markus B; Sägesser, Hans; Kirundi, Jorum; Macpherson, Andrew J; De Gottardi, Andrea

2015-05-01

Intestinal bacterial flora may induce splanchnic hemodynamic and histological alterations that are associated with portal hypertension (PH). We hypothesized that experimental PH would be attenuated in the complete absence of intestinal bacteria. We induced prehepatic PH by partial portal vein ligation (PPVL) in germ-free (GF) or mice colonized with altered Schaedler's flora (ASF). After 2 or 7 days, we performed hemodynamic measurements, including portal pressure (PP) and portosystemic shunts (PSS), and collected tissues for histomorphology, microbiology, and gene expression studies. Mice colonized with intestinal microbiota presented significantly higher PP levels after PPVL, compared to GF, mice. Presence of bacterial flora was also associated with significantly increased PSS and spleen weight. However, there were no hemodynamic differences between sham-operated mice in the presence or absence of intestinal flora. Bacterial translocation to the spleen was demonstrated 2 days, but not 7 days, after PPVL. Intestinal lymphatic and blood vessels were more abundant in colonized and in portal hypertensive mice, as compared to GF and sham-operated mice. Expression of the intestinal antimicrobial peptide, angiogenin-4, was suppressed in GF mice, but increased significantly after PPVL, whereas other angiogenic factors remained unchanged. Moreover, colonization of GF mice with ASF 2 days after PPVL led to a significant increase in intestinal blood vessels, compared to controls. The relative increase in PP after PPVL in ASF and specific pathogen-free mice was not significantly different. In the complete absence of gut microbial flora PP is normal, but experimental PH is significantly attenuated. Intestinal mucosal lymphatic and blood vessels induced by bacterial colonization may contribute to development of PH. © 2015 by the American Association for the Study of Liver Diseases.

[Intrauterine intestinal volvulus].

PubMed

Gawrych, Elzbieta; Chojnacka, Hanna; Wegrzynowski, Jerzy; Rajewska, Justyna

2009-07-01

Intrauterine intestinal volvulus is an extremely rare case of acute congenital intestinal obstruction. The diagnosis is usually possible in the third trimester of a pregnancy. Fetal midgut volvulus is most likely to be recognized by observing a typical clockwise whirlpool sign during color Doppler investigation. Multiple dilated intestinal loops with fluid levels are usually visible during the antenatal ultrasound as well. Physical and radiographic findings in the newborn indicate intestinal obstruction and an emergency surgery is required. The authors describe intrauterine volvulus in 3 female newborns in which surgical treatment was individualized. The decision about primary or delayed anastomosis after resection of the gangrenous part of the small bowel was made at the time of the surgery and depended on the general condition of the newborn, as well as presence or absence of meconium peritonitis. Double loop jejunostomy was performed in case of two newborns, followed by a delayed end-to-end anastomosis. In case of the third newborn, good blood supply of the small intestine after untwisting and 0.25% lignocaine injections into mesentery led to the assumption that the torsion was not complete and ischemia was reversible. In the two cases of incomplete rotation the cecum was sutured to the left abdominal wall to prevent further twisting. The postoperative course was uneventful and oral alimentation caused no problems. Physical development of all these children has been normal (current age: 1-2 years) and the parents have not observed any disorders or problems regarding passage of food through the alimentary canal. Prompt antenatal diagnosis of this surgical emergency and adequate choice of intervention may greatly reduce mortality due to intrauterine volvulus.

Imaging diagnosis--muscular hypertrophy of the small intestine and pseudodiverticula in a horse.

PubMed

Navas De Solís, Cristobal; Biscoe, Elisabeth W; Lund, Caleb M; Labbe, Karyn; Muñoz, Juan; Farnsworth, Kelly

2015-01-01

A 14-year-old Thoroughbred gelding was presented for chronic colic and weight loss. Transcutaneous and transrectal abdominal ultrasonography revealed distended, thickened small intestine with primary thickening of the muscularis and a focally more thickened loop with an echoic structure crossing the wall from the mucosa to the serosa. Visualization of diffuse thickening of the muscularis (muscular hypertrophy of the small intestine) and a focal lesion (pseudodiverticulum) helped clinicians make informed decisions. This case illustrates the importance of transabdominal and transrectal ultrasonography in horses with chronic colic and the relevance of considering the abnormalities in layering pattern of the intestinal wall. © 2014 American College of Veterinary Radiology.

Positive selection of the peripheral B cell repertoire in gut-associated lymphoid tissues.

PubMed

Rhee, Ki-Jong; Jasper, Paul J; Sethupathi, Periannan; Shanmugam, Malathy; Lanning, Dennis; Knight, Katherine L

2005-01-03

Gut-associated lymphoid tissues (GALTs) interact with intestinal microflora to drive GALT development and diversify the primary antibody repertoire; however, the molecular mechanisms that link these events remain elusive. Alicia rabbits provide an excellent model to investigate the relationship between GALT, intestinal microflora, and modulation of the antibody repertoire. Most B cells in neonatal Alicia rabbits express V(H)n allotype immunoglobulin (Ig)M. Within weeks, the number of V(H)n B cells decreases, whereas V(H)a allotype B cells increase in number and become predominant. We hypothesized that the repertoire shift from V(H)n to V(H)a B cells results from interactions between GALT and intestinal microflora. To test this hypothesis, we surgically removed organized GALT from newborn Alicia pups and ligated the appendix to sequester it from intestinal microflora. Flow cytometry and nucleotide sequence analyses revealed that the V(H)n to V(H)a repertoire shift did not occur, demonstrating the requirement for interactions between GALT and intestinal microflora in the selective expansion of V(H)a B cells. By comparing amino acid sequences of V(H)n and V(H)a Ig, we identified a putative V(H) ligand binding site for a bacterial or endogenous B cell superantigen. We propose that interaction of such a superantigen with V(H)a B cells results in their selective expansion.

Intraintestinal administration of ulinastatin protects against sepsis by relieving intestinal damage.

PubMed

Yang, Bingchang; Gao, Min; Wang, Kangkai; Jiang, Yu; Peng, Yue; Zhang, Huali; Yang, Mingshi; Xiao, Xianzhong

2017-05-01

Intravenous administration of ulinastatin (UTI), a broad spectral protease inhibitor, has been used on an experimental basis with severe sepsis patients in Asia. However, the effects of intraintestinal administration of UTI on intestinal and multiple organ damage in sepsis have not been reported. In this study, we established a sepsis model in rats using cecal ligation and puncture and compared the effects of intraintestinal administration of UTI through an artificial fistula of duodenum and intraperitoneal administration of UTI on the pathophysiological changes of sepsis. It was found that intraintestinal administration of UTI (1) significantly improved the survival of septic rats, (2) significantly reduced the serum levels of tumor necrosis factor-α, interleukin-1β, interleukin-6 as well as intestinal injury biomarkers diamine oxidase, D-lactic acid, and fluorescein isothiocyanate-dextran 4, and (3) significantly reduced intestinal microscopic and ultrastructural damage of septic rats. In addition, the protective effects of intraintestinal administration of UTI were significantly better than those of intraperitoneal administration of UTI. Overall, the present study for the first time revealed that intraintestinal administration of protease inhibitor UTI could reduce systemic inflammatory responses and multiple organ dysfunction in rats with sepsis by inhibiting autodigestion of intestinal wall due to proteases and provided new research ideas and experimental evidences for treatment of sepsis by intraintestinal administration of UTI. Copyright © 2016. Published by Elsevier Inc.

Translocation of Candida albicans is related to the blood flow of individual intestinal villi.

PubMed

Gianotti, L; Alexander, J W; Fukushima, R; Childress, C P

1993-08-01

Splanchnic ischemia is associated with increased bacterial translocation, but previous observations showed that translocation of Candida albicans did not occur uniformly among individual intestinal villi. This study was performed to investigate the relationship between the degree of Candida translocation and the microcirculation of individual villi. Thiry-Vella intestinal loops were created in eight guinea pigs. One week later, the distal aorta and right carotid artery were cannulated, and systemic blood pressure was recorded throughout the entire experiment. C. albicans (1 x 10(10)) was introduced into the Thiry-Vella loop, and the animals underwent a 40% full-thickness burn. Systolic hypotension was observed in the first 75 minutes postburn; then the systemic blood pressure returned to a normal range. Four hours after burn, 8 x 10(7) microspheres (10 microns) were injected into the aorta. The animals were sacrificed, and the Thiry-Vella loops were harvested and processed for light microscopy. At the microscopic level, within each villus, both the number of beads trapped in the arterioles and the number of Candida translocated into the enterocytes were counted. An inverse linear correlation between number of beads and number of translocated yeast per individual villus was found (r = -0.78; P < 0.005). These data provide further evidence that blood flow is an important determinant of the magnitude of microbial translocation, even within individual villi.

A case of child death caused by intestinal volvulus following magnetic toy ingestion.

PubMed

Olczak, Mieszko; Skrzypek, Ewa

2015-05-01

An 8-year boy was admitted to the ER of one of Warsaw's pediatric hospitals with a history of having bloody vomiting the day before. During admission the boy collapsed and lost consciousness. CPR was unsuccessful. On medico-legal autopsy, two foreign objects (small magnetic spheres--0.5 cm in diameter) were found in two different places in the small and large intestines and were notably attracted magnetically one to another. A loop of approximately 1-m length with features of small intestinal hemorrhagic necrosis and small intestinal mechanical obstruction was found. The cause of death was intestinal volvulus and small intestinal mechanical obstruction caused by ingestion of foreign objects (two neodymium magnets). Most likely these small magnetic spheres were part of a popular toy, the safety of which, lately, has been widely discussed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Studies on Inhibition of Intestinal Absorption of Radioactive Strontium

PubMed Central

Skoryna, Stanley C.; Paul, T. M.; Edward, Deirdre Waldron

1964-01-01

A method is reported which permits selective suppression of absorption of radioactive strontium from ingested food material, permitting the calcium to be available to the body. Studies were carried out in vivo by injection of Sr89 and Ca45 in the presence of inert carrier into ligated intestinal segments in rats, and the amount of absorption was measured by standard monitoring techniques. The pattern of absorption of both ions is very similar but the rate of absorption is different. It was found that the polyelectrolyte, sodium alginate, obtained from brown algae (Phaeophyceae), injected simultaneously with radiostrontium effectively reduces the absortion of Sr89 from all segments of the intestine by as much as 50-80% of the control values. No significant reduction in absorption of Ca45 was observed in equivalent concentrations. The reduction in blood levels of Sr89 and in bone uptake corresponded to the absorption pattern. The difference in the effect on strontium and calcium absorption may be due to differences in the binding capacity of sodium alginate from the two metal ions under the conditions present in vivo. PMID:14180534

Blind loop syndrome

MedlinePlus

Treatment most often starts with antibiotics for the excess bacteria growth, along with vitamin B12 supplements. If antibiotics are not effective, surgery may be needed to help food flow through the intestines.

[Treatment of postoperative abdominal hernias with polypropylene endoprosthesis].

PubMed

Chakhvadze, B Iu; Nakashidze, D Kh

2009-06-01

The results of the surgical treatment of 82 patients with postoperative abdominal hernias were analysed. All of the patients underwent surgery with polypropylene endoprosthesis. The choice of a hernioplasty method depended on relative volume of postoperative hernia. Middle-sized hernias were indications for reconstructive surgery (complete adaptation of muscular and aponeurotic layers was maintained). The large and gigantic hernias were indications for correcting surgery (specified diastasis of muscular and aponeurotic layers was maintained). In case of lacking of peritoneum (30 patients) greater omentum was used for isolation of the net from intestinal loops. It is concluded that greater omentum provides good extraperitonisation of transplant from intestinal loop and prevents complications due to contact of net with abdominal organs. Postoperative complications mainly were local and seen in 29% cases. There were no lethal outcomes.

Early immune response following Salmonella enterica subspecies enterica serovar Typhimurium infection in porcine jejunal gut loops

PubMed Central

Meurens, François; Berri, Mustapha; Auray, Gael; Melo, Sandrine; Levast, Benoît; Virlogeux-Payant, Isabelle; Chevaleyre, Claire; Gerdts, Volker; Salmon, Henri

2009-01-01

Salmonella enterica subspecies enterica serovar Typhimurium, commonly called S. Typhimurium, can cause intestinal infections in humans and various animal species such as swine. To analyze the host response to Salmonella infection in the pig we used an in vivo gut loop model, which allows the analysis of multiple immune responses within the same animal. Four jejunal gut-loops were each inoculated with 3×108 cfu of S. Typhimurium in 3 one-month-old piglets and mRNA expressions of various cytokines, chemokines, transcription factors, antimicrobial peptides, toll like and chemokine receptors were assessed by quantitative real-time PCR in the Peyer’s patch and the gut wall after 24 h. Several genes such as the newly cloned CCRL1/CCX-CKR were assessed for the first time in the pig at the mRNA level. Pro-inflammatory and T-helper type-1 (Th1) cytokine mRNA were expressed at higher levels in infected compared to non-infected control loops. Similarly, some B cell activation genes, NOD2 and toll like receptor 2 and 4 transcripts were more expressed in both tissues while TLR5 mRNA was down-regulated. Interestingly, CCL25 mRNA expression as well as the mRNA expressions of its receptors CCR9 and CCRL1 were decreased both in the Peyer’s patch and gut wall suggesting a potential Salmonella strategy to reduce lymphocyte homing to the intestine. In conclusion, these results provide insight into the porcine innate mucosal immune response to infection with entero-invasive microorganisms such as S. Typhimurium. In the future, this knowledge should help in the development of improved prophylactic and therapeutic approaches against porcine intestinal S. Typhimurium infections. PMID:18922229

Potential probiotic attributes of a new strain of Bacillus coagulans CGMCC 9951 isolated from healthy piglet feces.

PubMed

Gu, Shao-Bin; Zhao, Li-Na; Wu, Ying; Li, Shi-Chang; Sun, Jian-Rui; Huang, Jing-Fang; Li, Dan-Dan

2015-06-01

A new strain of Bacillus coagulans CGMCC 9551, which has a broad range of antibacterial activities against six main pathogenic bacteria including Escherichia coli O8, Staphylococcus aureus, Salmonella enterica subsp. enterica serovar enteritidis, Streptococcus suis, Listeria monocytogenes and Pasteurella multocida, was isolated from healthy piglet feces. In adhesion assay, the isolate exhibited a stronger adhesion to pig intestinal mucus than that of B. subtilis JT143 and L. acidophilus LY24 respectively isolated from BioPlus(®)2B and FloraFIT(®) Probiotics (P < 0.05). The adhesion activity reached 44.5 ± 3.2, 48.9 ± 2.6, 42.6 ± 3.3 and 37.6 ± 2.4% to jejunum, ileum, transverse colon and sigmoid colon, separately. The survival rate of B. coagulans CGMCC 9551 was reduced by only 20% at 4 h exposure under 0.9% w/v bile salt. The strain was fully resistant to pH 2 for 2 h with 90.1 ± 3.5% survival and susceptible to 15 antibiotics commonly used in veterinary medicine. Additionally, the bacteria showed amylase, protease and cellulase activities. The safety assessment demonstrated the lack of toxicity potential in B. coagulans CGMCC 9551 by ligated rabbit ileal loop assay, acute and subchronic toxicity test. These results implied that that the new strain of B. coagulans CGMCC 9951 isolated from healthy piglet feces has promising probiotic characteristics and offers desirable opportunities for its successful commercialization as one excellent candidate probiotic.

The contribution of gastric digestion and ingestion of amino acids on the postprandial rise in oxygen consumption, heart rate and growth of visceral organs in pythons.

PubMed

Enok, Sanne; Simonsen, Lasse Stærdal; Wang, Tobias

2013-05-01

To investigate the contribution of gastric and intestinal processes to the postprandial rise in metabolism in pythons (Python regius), we measured oxygen consumption after ligation of the pyloric sphincter to prevent the chyme from entering the intestine. Pyloric blockade reduced the postprandial rise in metabolism during the first 18h after ingestion of mice amounting to 18% of the snake's body mass by 60%. In another series of the experiments, we showed that infusion of amino acids directly into the stomach or the intestine elicited similar metabolic responses. This indicates a lower gastric contribution to the SDA response than previously reported. To include an assessment of the gastric contribution to the postprandial cardiovascular response, we also measured blood and heart rate. While heart rate increased during digestion in snakes with pyloric blockade, there was no rise in the double-blocked heart rates compared to fasting controls. Thus, the non-adrenergic-non-cholinergic factor that stimulates heart rate during digestion does not stem from the stomach. Finally, there was no growth of the visceral organs in response to digestion when chyme was prevented from reaching the intestine. Copyright © 2013 Elsevier Inc. All rights reserved.

Intestinal secretion of immunoglobulins and antibodies to Escherichia coli in the pig

PubMed Central

Porter, P.; Noakes, D. E.; Allen, W. D.

1970-01-01

Immunoglobulins and antibodies against Escherichia coli 0141 have been studied in porcine intestinal secretions obtained from Thiry Vella loops prepared in the mid jejunum of 4 animals. The molecular size of the secreted immunoglobulins were investigated by gel filtration and sucrose density gradient ultra-centrifugation. Intestinal IgM was found to have 7S characteristics and intestinal IgA mainly 11S characteristics similar to secretory IgA isolated from porcine milk. Immune inhibition studies with rabbit anti-IgA-globulin serum produced complete elimination of E. coli 0141 antibodies detected by direct haemagglutination. In one animal incomplete antibody assayed by antiglobulin haemagglutination was identified in fractions associated with IgM and IgG. Immunofluorescent studies were made to correlate immunoglobulins in the small intestinal tissue with weaning. ImagesFIG. 1FIG. 2FIG. 7 PMID:4193669

How securely is the testicular artery occluded in the spermatic cord by using a ligature?

PubMed

Rijkenhuizen, A B M; Sommerauer, S; Fasching, M; Velde, K; Peham, C

2013-09-01

There are no studies on the ideal ligature technique for the spermatic cord. To compare the maximal resistance pressure in the testicular artery and the maximal tensile forces to produce failure of 2 different ligature techniques used for ligation of the equine spermatic cord. The capabilities of 2 types of ligatures, single knot loop and double knot loop, were assessed using a pressure-resistance test in testicular arteries and with an in vitro mechanical evaluation of the tensile strength by single cycle-to-failure testing. In the pressure-resistance test, the mean ± s.d. peak force at failure of the single knot loop was 354.4 ± 91.7 mmHg and for the double knot loop 303.2 ± 62.0 mmHg. There was no significant difference between the maximal load to failure of the single knot loop and double knot loop technique. The pressure needed for rupture was significantly higher (P = 0.001) than for leakage. The maximal tensile force at failure of the single knot loop was significantly higher than the double knot loop (P = 0.028). There was no significant difference in load elongation properties to failure between the single knot loop and double knot loop. Although no significant differences were obtained in the pressure-resistance test, the single knot loop sustained significantly greater load to failure than the double knot loop in single cycle-to-failure testing. Based on these findings, it would appear that the performance of the single knot loop should be superior to the double knot loop. Both ligature techniques are able to withstand the normal physiological intravascular pressure. The single knot loop has the greater breaking strength of the 2 ligatures tested and is less time consuming to perform and may therefore have advantages during equine castration. © 2012 EVJ Ltd.

Cyclooxygenase-2 Deficiency Leads to Intestinal Barrier Dysfunction and Increased Mortality During Polymicrobial Sepsis 1

PubMed Central

Fredenburgh, Laura E.; Velandia, Margarita M. Suarez; Ma, Jun; Olszak, Torsten; Cernadas, Manuela; Englert, Joshua A.; Chung, Su Wol; Liu, Xiaoli; Begay, Cynthia; Padera, Robert F.; Blumberg, Richard S.; Walsh, Stephen R.; Baron, Rebecca M.; Perrella, Mark A.

2011-01-01

Sepsis remains the leading cause of death in critically ill patients despite modern advances in critical care. Intestinal barrier dysfunction may lead to secondary bacterial translocation and the development of the multiple organ dysfunction syndrome during sepsis. Cyclooxygenase-2 (COX-2) is highly upregulated in the intestine during sepsis and we hypothesized that it may be critical in the maintenance of intestinal epithelial barrier function during peritonitis-induced polymicrobial sepsis. COX-2−/− and COX-2+/+ BALB/c mice underwent cecal ligation and puncture (CLP) or sham surgery. Mice chimeric for COX-2 were derived by bone marrow transplantation and underwent CLP. C2BBe1 cells, an intestinal epithelial cell line, were treated with the COX-2 inhibitor NS-398, PGD2, or vehicle and stimulated with cytokines. COX-2−/− mice developed exaggerated bacteremia and increased mortality compared with COX-2+/+ mice following CLP. Mice chimeric for COX-2 exhibited the recipient phenotype suggesting that epithelial COX-2 expression in the ileum attenuates bacteremia following CLP. Absence of COX-2 significantly increased epithelial permeability of the ileum and reduced expression of the tight junction proteins zonula occludens-1 (ZO-1), occludin, and claudin-1 in the ileum following CLP. Furthermore, PGD2 attenuated cytokine-induced hyperpermeability and ZO-1 downregulation in NS-398-treated C2BBe1 cells. Our findings reveal that absence of COX-2 is associated with enhanced intestinal epithelial permeability and leads to exaggerated bacterial translocation and increased mortality during peritonitis-induced sepsis. Taken together, our results suggest that epithelial expression of COX-2 in the ileum is a critical modulator of tight junction protein expression and intestinal barrier function during sepsis. PMID:21967897

Anti-inflammatory and antioxidant effects of infliximab on acute lung injury in a rat model of intestinal ischemia/reperfusion.

PubMed

Guzel, Ahmet; Kanter, Mehmet; Guzel, Aygul; Pergel, Ahmet; Erboga, Mustafa

2012-06-01

The purpose of this study was to investigate the role of infliximab on acute lung injury induced by intestinal ischemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into three groups: sham, I/R and I/R+ infliximab; each group contain 10 animals. Sham group animals underwent laparotomy without I/R injury. After I/R groups animals underwent laparotomy, 1 h of superior mesenteric artery ligation were followed by 1 h of reperfusion. In the infliximab group, 3 days before I/R, infliximab (3 mg/kg) was administered by intravenously. All animals were sacrificed at the end of reperfusion and lung tissues samples were obtained for biochemical and histopathological investigation in all groups. To date, no more biochemical and histopathological changes on intestinal I/R injury in rats by infliximab treatment have been reported. Infliximab treatment significantly decreased the elevated tissue malondialdehyde levels and increased of reduced superoxide dismutase, and glutathione peroxidase enzyme activities in lung tissues samples. Intestinal I/R caused severe histopathological injury including edema, hemorrhage, increased thickness of the alveolar wall and a great number of inflammatory cells that infiltrated the interstitium and alveoli. Infliximab treatment significantly attenuated the severity of intestinal I/R injury. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase and arise in the expression of surfactant protein D in lung tissue of acute lung injury induced by intestinal I/R with infliximab therapy. It was concluded that infliximab treatment might be beneficial in acute lung injury, therefore, shows potential for clinical use. Because of its anti-inflammatory and antioxidant effects, infliximab pretreatment may have protective effects in acute lung injury induced by intestinal I/R.

Naringin attenuates MLC phosphorylation and NF-κB activation to protect sepsis-induced intestinal injury via RhoA/ROCK pathway.

PubMed

Li, Zhiling; Gao, Ming; Yang, Bingchang; Zhang, Huali; Wang, Kangkai; Liu, Zuoliang; Xiao, Xianzhong; Yang, Mingshi

2018-07-01

Sepsis is commonly associated with excessive stimulation of host immune system and result in multi-organ failure dysfunction. Naringin has been reported to exhibit a variety of biological effects. The present study aimed to investigate the protective effect of naringin on sepsis-induced injury of intestinal barrier function in vivo and in vitro. Mice were randomly divided into 4 groups named sham (n = 20), CLP + vehicle (n = 20), CLP + NG (30 mg/kg) (n = 20) and CLP + NG (60 mg/kg) (n = 20) groups. Sepsis was induced by cecal ligation and puncture (CLP). H&E staining and transmission electron microscopy (TEM) were performed to observe intestinal mucosal morphology. ELISA was used to determine the intestinal permeability and inflammatory response in vivo and in vitro. Western blot and RhoA activity assay were performed to determine the levels of tight junction proteins and the activation of indicated signaling pathways. MTT assay was used to determine cell viability. Naringin improved survival rate of CLP mice and alleviated sepsis-induced intestinal mucosal injury. Furthermore, naringin improved impaired intestinal permeability and inhibited the release of TNF-α and IL-6, while increased IL-10 level in CLP mice and lipopolysaccharide (LPS)-stimulated MODE-K cells in a dose-dependent manner. Naringin increased the expression of tight junction proteins ZO-1 and claudin-1 via RhoA/ROCK/NF-κB/MLCK/MLC signaling pathway in vivo and in vitro. Naringin improved sepsis-induced intestinal injury via RhoA/ROCK/NF-κB/MLCK/MLC signaling pathway in vivo and in vitro. Copyright © 2018. Published by Elsevier Masson SAS.

Glucagon-like peptide-2 protects impaired intestinal mucosal barriers in obstructive jaundice rats

PubMed Central

Chen, Jun; Dong, Jia-Tian; Li, Xiao-Jing; Gu, Ye; Cheng, Zhi-Jian; Cai, Yuan-Kun

2015-01-01

AIM: To observe the protective effect of glucagon-like peptide-2 (GLP-2) on the intestinal barrier of rats with obstructive jaundice and determine the possible mechanisms of action involved in the protective effect. METHODS: Thirty-six Sprague-Dawley rats were randomly divided into a sham operation group, an obstructive jaundice group, and a GLP-2 group; each group consisted of 12 rats. The GLP-2 group was treated with GLP-2 after the day of surgery, whereas the other two groups were treated with the same concentration of normal saline. Alanine aminotransferase (ALT), total bilirubin, and endotoxin levels were recorded at 1, 3, 7, 10 and 14 d. Furthermore, on the 14th day, body weight, the wet weight of the small intestine, pathological changes of the small intestine and the immunoglobulin A (IgA) expressed by plasma cells located in the small intestinal lamina propria were recorded for each group. RESULTS: In the rat model, jaundice was obvious, and the rats’ activity decreased 4-6 d post bile duct ligation. Compared with the sham operation group, the obstructive jaundice group displayed increased yellow staining of abdominal visceral serosa, decreased small intestine wet weight, thinning of the intestinal muscle layer and villi, villous atrophy, uneven height, fusion, partial villous epithelial cell shedding, substantial inflammatory cell infiltration and significantly reduced IgA expression. However, no significant gross changes were noted between the GLP-2 and sham groups. With time, the levels of ALT, endotoxin and bilirubin in the GLP-2 group were significantly increased compared with the sham group (P < 0.01). The increasing levels of the aforementioned markers were more significant in the obstructive jaundice group than in the GLP-2 group (P < 0.01). CONCLUSION: GLP-2 reduces intestinal mucosal injuries in obstructive jaundice rats, which might be attributed to increased intestinal IgA and reduced bilirubin and endotoxin. PMID:25593463

Glucagon-like peptide-2 protects impaired intestinal mucosal barriers in obstructive jaundice rats.

PubMed

Chen, Jun; Dong, Jia-Tian; Li, Xiao-Jing; Gu, Ye; Cheng, Zhi-Jian; Cai, Yuan-Kun

2015-01-14

To observe the protective effect of glucagon-like peptide-2 (GLP-2) on the intestinal barrier of rats with obstructive jaundice and determine the possible mechanisms of action involved in the protective effect. Thirty-six Sprague-Dawley rats were randomly divided into a sham operation group, an obstructive jaundice group, and a GLP-2 group; each group consisted of 12 rats. The GLP-2 group was treated with GLP-2 after the day of surgery, whereas the other two groups were treated with the same concentration of normal saline. Alanine aminotransferase (ALT), total bilirubin, and endotoxin levels were recorded at 1, 3, 7, 10 and 14 d. Furthermore, on the 14(th) day, body weight, the wet weight of the small intestine, pathological changes of the small intestine and the immunoglobulin A (IgA) expressed by plasma cells located in the small intestinal lamina propria were recorded for each group. In the rat model, jaundice was obvious, and the rats' activity decreased 4-6 d post bile duct ligation. Compared with the sham operation group, the obstructive jaundice group displayed increased yellow staining of abdominal visceral serosa, decreased small intestine wet weight, thinning of the intestinal muscle layer and villi, villous atrophy, uneven height, fusion, partial villous epithelial cell shedding, substantial inflammatory cell infiltration and significantly reduced IgA expression. However, no significant gross changes were noted between the GLP-2 and sham groups. With time, the levels of ALT, endotoxin and bilirubin in the GLP-2 group were significantly increased compared with the sham group (P < 0.01). The increasing levels of the aforementioned markers were more significant in the obstructive jaundice group than in the GLP-2 group (P < 0.01). GLP-2 reduces intestinal mucosal injuries in obstructive jaundice rats, which might be attributed to increased intestinal IgA and reduced bilirubin and endotoxin.

Oral exposure to polystyrene nanoparticles affects iron absorption

NASA Astrophysics Data System (ADS)

Mahler, Gretchen J.; Esch, Mandy B.; Tako, Elad; Southard, Teresa L.; Archer, Shivaun D.; Glahn, Raymond P.; Shuler, Michael L.

2012-04-01

The use of engineered nanoparticles in food and pharmaceuticals is expected to increase, but the impact of chronic oral exposure to nanoparticles on human health remains unknown. Here, we show that chronic and acute oral exposure to polystyrene nanoparticles can influence iron uptake and iron transport in an in vitro model of the intestinal epithelium and an in vivo chicken intestinal loop model. Intestinal cells that are exposed to high doses of nanoparticles showed increased iron transport due to nanoparticle disruption of the cell membrane. Chickens acutely exposed to carboxylated particles (50 nm in diameter) had a lower iron absorption than unexposed or chronically exposed birds. Chronic exposure caused remodelling of the intestinal villi, which increased the surface area available for iron absorption. The agreement between the in vitro and in vivo results suggests that our in vitro intestinal epithelium model is potentially useful for toxicology studies.

Detection of intestinal obstruction by radionuclide scan: case report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chaudhuri, T.K.

1976-11-01

The value of /sup 99m/Technetium-pertechnetate abdomen scan has recently been established in the diagnosis of Meckel's diverticulum, intussusception, and inflamed appendix. The purpose of this paper is to report a case with small intestinal obstruction secondary to fibrous adhesions which resulted from a previous surgery, in whom a /sup 99m/Technetium-pertechnetate abdomen scan showed increased radionuclide concentration in the area of dilated loop of bowel proximal to the site of obstruction.

Epidermal growth factor treatment decreases mortality and is associated with improved gut integrity in sepsis.

PubMed

Clark, Jessica A; Clark, Andrew T; Hotchkiss, Richard S; Buchman, Timothy G; Coopersmith, Craig M

2008-07-01

Epidermal growth factor (EGF) is a cytoprotective peptide that has healing effects on the intestinal mucosa. We sought to determine whether systemic administration of EGF after the onset of sepsis improved intestinal integrity and decreased mortality. FVB/N mice were subjected to either sham laparotomy or 2 x 23 cecal ligation and puncture (CLP). Septic mice were further randomized to receive injection of either 150 microg kg(-1) d(-1) (i.p.) EGF or 0.9% saline (i.p.). Circulating EGF levels were decreased after CLP compared with sham animals but were unaffected by giving exogenous EGF treatment. In contrast, intestinal EGF levels increased after CLP and were further augmented by exogenous EGF treatment. Intestinal EGF receptor was increased after CLP, whether assayed by immunohistochemistry, real-time polymerase chain reaction, or Western blot, and exogenous EGF treatment decreased intestinal EGF receptor. Villus length decreased 2-fold between sham and septic animals, and EGF treatment resulted in near total restitution of villus length. Sepsis decreased intestinal proliferation and increased intestinal apoptosis. This was accompanied by increased expression of the proapoptotic proteins Bid and Fas-associated death domain, as well as the cyclin-dependent kinase inhibitor p21 cip1/waf Epidermal growth factor treatment after the onset of sepsis restored both proliferation and apoptosis to levels seen in sham animals and normalized expression of Bid, Fas-associated death domain, and p21 cip1/waf . To determine whether improvements in gut homeostasis were associated with a decrease in sepsis-induced mortality, septic mice with or without EGF treatment after CLP were followed 7 days for survival. Mortality decreased from 60% to 30% in mice treated with EGF after the onset of sepsis (P < 0.05). Thus, EGF may be a potential therapeutic agent for the treatment of sepsis in part due to its ability to protect intestinal integrity.

Epidermal growth factor treatment decreases mortality and is associated with improved gut integrity in sepsis

PubMed Central

Clark, Jessica A.; Clark, Andrew T.; Hotchkiss, Richard S.; Buchman, Timothy G.; Coopersmith, Craig M.

2007-01-01

Epidermal growth factor (EGF) is a cytoprotective peptide that has healing effects on the intestinal mucosa. We sought to determine whether systemic administration of EGF following the onset of sepsis improved intestinal integrity and decreased mortality. FVB/N mice were subjected to either sham laparotomy or 2×23 cecal ligation and puncture (CLP). Septic mice were further randomized to receive intraperitoneal injection of either 150 μg/kg/day EGF or 0.9% saline. Circulating EGF levels were decreased following CLP compared to sham animals but were unaffected by giving exogenous EGF treatment. In contrast, intestinal EGF levels increased following CLP, and were further augmented by exogenous EGF treatment. Intestinal EGF-receptor (EGF-R) was increased following CLP whether assayed by immunohistochemistry, real-time PCR or western blot, and exogenous EGF treatment decreased intestinal EGF-R. Villus length decreased 2-fold between sham and septic animals, and EGF treatment resulted in near total restitution of villus length. Sepsis decreased intestinal proliferation and increased intestinal apoptosis. This was accompanied by increased expression of the pro-apoptotic proteins Bid and FADD, as well as the cyclin-dependent kinase inhibitor p21cip1/waf. EGF treatment after the onset of sepsis restored both proliferation and apoptosis to levels seen in sham animals and normalized expression of Bid, FADD, and p21cip1/waf. To determine whether improvements in gut homeostasis were associated with a decrease in sepsis-induced mortality, septic mice with or without EGF treatment after CLP were followed seven days for survival. Mortality decreased from 60% to 30% in mice treated with EGF after the onset of sepsis (p<0.05). EGF may thus be a potential therapeutic agent for the treatment of sepsis, in part due to its ability to protect intestinal integrity. PMID:18004230

A Positive Regulatory Loop between a Wnt-Regulated Non-coding RNA and ASCL2 Controls Intestinal Stem Cell Fate.

PubMed

Giakountis, Antonis; Moulos, Panagiotis; Zarkou, Vasiliki; Oikonomou, Christina; Harokopos, Vaggelis; Hatzigeorgiou, Artemis G; Reczko, Martin; Hatzis, Pantelis

2016-06-21

The canonical Wnt pathway plays a central role in stem cell maintenance, differentiation, and proliferation in the intestinal epithelium. Constitutive, aberrant activity of the TCF4/β-catenin transcriptional complex is the primary transforming factor in colorectal cancer. We identify a nuclear long non-coding RNA, termed WiNTRLINC1, as a direct target of TCF4/β-catenin in colorectal cancer cells. WiNTRLINC1 positively regulates the expression of its genomic neighbor ASCL2, a transcription factor that controls intestinal stem cell fate. WiNTRLINC1 interacts with TCF4/β-catenin to mediate the juxtaposition of its promoter with the regulatory regions of ASCL2. ASCL2, in turn, regulates WiNTRLINC1 transcriptionally, closing a feedforward regulatory loop that controls stem cell-related gene expression. This regulatory circuitry is highly amplified in colorectal cancer and correlates with increased metastatic potential and decreased patient survival. Our results uncover the interplay between non-coding RNA-mediated regulation and Wnt signaling and point to the diagnostic and therapeutic potential of WiNTRLINC1. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Meal-stimulated release of methionine-enkephalin into the canine jejunal lumen.

PubMed Central

Money, S R; Petroianu, A; Gintzler, A R; Jaffe, B M

1988-01-01

Application of enkephalins to the luminal surface of the bowel augments intestinal absorption. However, to date, endogenous enkephalins have not been demonstrated within intestinal luminal fluid. To determine whether enkephalins are present in the intestinal lumen, five adult dogs had 25-cm chronic jejunal Thiry-Vella loops constructed. Dogs were studied in the awake, fasted state. Jejunal loops were perfused with isoosmotic, neutral Krebs buffer containing protease inhibitors. After basal sampling, the dogs received a high fat meat meal. Collections were made during the meal and for 60 min postprandially. Luminal met-enkephalin levels were determined by radioimmunoassay and confirmed by HPLC. HPLC separation of luminal samples demonstrated two immunoreactive peaks which co-eluted with pure met-enkephalin and met-enkephalin-sulfoxide. Basal met-enkephalin outputs averaged 52 +/- 13 ng/min. The meal significantly increased mean luminal met-enkephalin output to 137 +/- 71 ng/min. During the initial 20-min postprandial period, output remained elevated (180 +/- 73 ng/min), after which it returned to basal levels. We conclude that met-enkephalin is present in the jejunal lumen, and that luminal release of this opioid is augmented by a meal. Images PMID:3343342

Myosin light chain kinase knockout improves gut barrier function and confers a survival advantage in polymicrobial sepsis.

PubMed

Lorentz, C Adam; Liang, Zhe; Meng, Mei; Chen, Ching-Wen; Yoseph, Benyam P; Breed, Elise R; Mittal, Rohit; Klingensmith, Nathan J; Farris, Alton B; Burd, Eileen M; Koval, Michael; Ford, Mandy L; Coopersmith, Craig M

2017-06-07

Sepsis-induced intestinal hyperpermeability is mediated by disruption of the epithelial tight junction, which is closely associated with the peri-junctional actin-myosin ring. Myosin light chain kinase (MLCK) phosphorylates the myosin regulatory light chain, resulting in increased permeability. The purpose of this study was to determine whether genetic deletion of MLCK would alter gut barrier function and survival from sepsis. MLCK -/- and wild type (WT) mice were subjected to cecal ligation and puncture and assayed for both survival and mechanistic studies. Survival was significantly increased in MLCK -/- mice (95% vs. 24%, p<0.0001). Intestinal permeability increased in septic WT mice compared to unmanipulated mice. In contrast, permeability in septic MLCK -/- mice was similar to that seen in unmanipulated animals. Improved gut barrier function in MLCK -/- mice was associated with increases in the tight junction mediators ZO-1 and claudin 15 without alterations in claudin 1, 2, 3, 4, 5, 7, 8, 13, occludin or JAM-A. Other components of intestinal integrity (apoptosis, proliferation and villus length) were unaffected by MLCK deletion as were local peritoneal inflammation and distant lung injury. Systemic IL-10 was decreased greater than 10-fold in MLCK -/- mice; however, survival was similar between septic MLCK -/- mice given exogenous IL-10 or vehicle. These data demonstrate that deletion of MLCK improves survival following sepsis, associated with normalization of intestinal permeability and selected tight junction proteins.

Robotic Low Ligation of the Inferior Mesenteric Artery for Rectal Cancer Using the Firefly Technique.

PubMed

Bae, Sung Uk; Min, Byung Soh; Kim, Nam Kyu

2015-07-01

By integrating intraoperative near infrared fluorescence imaging into a robotic system, surgeons can identify the vascular anatomy in real-time with the technical advantages of robotics that is useful for meticulous lymphovascular dissection. Herein, we report our initial experience of robotic low ligation of the inferior mesenteric artery (IMA) with real-time identification of the vascular system for rectal cancer using the Firefly technique. The study group included 11 patients who underwent a robotic total mesorectal excision with preservation of the left colic artery for rectal cancer using the Firefly technique between July 2013 and December 2013. The procedures included five low anterior resections and six ultra-low anterior resections with loop ileostomy. The median total operation time was 327 min (226-490). The low ligation time was 10 min (6-20), and the time interval between indocyanine green injection and division of the sigmoid artery was 5 min (2-8). The estimated blood loss was 200 mL (100-500). The median time to soft diet was 4 days (4-5), and the median length of stay was 7 days (5-9). Three patients developed postoperative complications; one patients developed anal stricture, one developed ileus, and one developed non-complicated intraabdominal fluid collection. The median total number of lymph nodes harvested was 17 (9-29). Robotic low ligation of the IMA with real-time identification of the vascular system for rectal cancer using the Firefly technique is safe and feasible. This technique can allow for precise lymph node dissection along the IMA and facilitate the identification of the left colic branch of the IMA.

Developments in Methods for Measuring the Intestinal Absorption of Nanoparticle-Bound Drugs

PubMed Central

Liu, Wei; Pan, Hao; Zhang, Caiyun; Zhao, Liling; Zhao, Ruixia; Zhu, Yongtao; Pan, Weisan

2016-01-01

With the rapid development of nanotechnology, novel drug delivery systems comprising orally administered nanoparticles (NPs) have been paid increasing attention in recent years. The bioavailability of orally administered drugs has significant influence on drug efficacy and therapeutic dosage, and it is therefore imperative that the intestinal absorption of oral NPs be investigated. This review examines the various literature on the oral absorption of polymeric NPs, and provides an overview of the intestinal absorption models that have been developed for the study of oral nanoparticles. Three major categories of models including a total of eight measurement methods are described in detail (in vitro: dialysis bag, rat gut sac, Ussing chamber, cell culture model; in situ: intestinal perfusion, intestinal loops, intestinal vascular cannulation; in vivo: the blood/urine drug concentration method), and the advantages and disadvantages of each method are contrasted and elucidated. In general, in vitro and in situ methods are relatively convenient but lack accuracy, while the in vivo method is troublesome but can provide a true reflection of drug absorption in vivo. This review summarizes the development of intestinal absorption experiments in recent years and provides a reference for the systematic study of the intestinal absorption of nanoparticle-bound drugs. PMID:27455239

Intestine-specific overexpression of IL-10 improves survival in polymicrobial sepsis.

PubMed

Rajan, Saju; Vyas, Dinesh; Clark, Andrew T; Woolsey, Cheryl A; Clark, Jessica A; Hotchkiss, Richard S; Buchman, Timothy G; Coopersmith, Craig M

2008-04-01

Targeted IL-10 therapy improves survival in preclinical models of critical illness, and intestine-specific IL-10 decreases inflammation in models of chronic Inflammatory disease. We therefore sought to determine whether intestine-specific overexpression of IL-10 would improve survival in sepsis. Transgenic mice that overexpress IL-10 in their gut epithelium (Fabpi-IL-10 mice) and wild-type (WT) littermates (n = 127) were subjected to cecal ligation and puncture with a 27-gauge needle. The 7-day survival rate was 45% in transgenic animals and 30% in WT animals (P < or = 0.05). Systemic levels of IL-10 were undetectable in both groups of animals under basal conditions and were elevated to a similar degree in septic animals regardless of whether they expressed the transgene. Local parameter of injury, including gut epithelial apoptosis, intestinal permeability, peritoneal lavage cytokines, and stimulated cytokines from intraepithelial lymphocytes, were similar between transgenic and WT mice. However, in stimulated splenocytes, proinflammatory cytokines monocyte chemoattractant protein 1 (189 +/- 43 vs. 40 +/- 8 pg/mL) and IL-6 (116 +/- 28 vs. 34 +/- 9 pg/mL) were lower in Fabpi-IL-10 mice than WT littermates despite the intestine-specific nature of the transgene (P < 0.05). Cytokine levels were similar in blood and bronchoalveolar lavage fluid between the 2 groups, as were circulating LPS levels. Transgenic mice also had lower white blood cell counts associated with lower absolute neutrophil counts (0.5 +/- 0.1 vs. 1.0 +/- 0.2 10(3)/mm3; P < 0.05). These results indicate that gut-specific overexpression of IL-10 improves survival in a murine model of sepsis, and interactions between the intestinal epithelium and the systemic immune system may play a role in conferring this survival advantage.

Intestine-specific overexpression of IL-10 improves survival in polymicrobial sepsis

PubMed Central

Rajan, Saju; Vyas, Dinesh; Clark, Andrew T; Woolsey, Cheryl A; Clark, Jessica A; Hotchkiss, Richard S; Buchman, Timothy G; Coopersmith, Craig M

2007-01-01

Targeted Interleukin (IL)-10 therapy improves survival in preclinical models of critical illness, and intestine-specific IL-10 decreases inflammation in models of chronic inflammatory disease. We therefore sought to determine whether intestine-specific overexpression of IL-10 would improve survival in sepsis. Transgenic mice that overexpress IL-10 in their gut epithelium (Fabpi-IL-10 mice) and wild type (WT) littermates (n=127) were subjected to cecal ligation and puncture with a 27-gauge needle. Seven-day survival was 45% in transgenic animals and 30% in WT animals (p≤0.05). Systemic levels of IL-10 were undetectable in both groups of animals under basal conditions and were elevated to a similar degree in septic animals, regardless of whether they expressed the transgene. Local parameters of injury including gut epithelial apoptosis, intestinal permeability, peritoneal lavage cytokines and stimulated cytokines from intraepithelial lymphocytes were similar between transgenic and wildtype mice. However, in stimulated splenocytes, pro-inflammatory cytokines MCP-1 (189 ± 43 pg/ml vs. 40 ± 8 pg/ml) and IL-6 (116 ± 28 pg/ml vs. 34 ± 9 pg/ml) were lower in Fabpi-IL-10 mice than WT littermates despite the intestine-specific nature of the transgene (p<0.05). Cytokine levels were similar in blood and bronchoalveolar lavage fluid between the two groups as were circulating LPS levels. Transgenic mice also had lower white blood cell counts, associated with lower absolute neutrophil counts (0.5 ± 0.1 103/mm3 vs. 1.0 ± 0.2 103/mm3, p<0.05). These results indicate that gut-specific overexpression of IL-10 improves survival in a murine model of sepsis, and interactions between the intestinal epithelium and the systemic immune system may play a role in conferring this survival advantage. PMID:17998890

[Pathogenic activity modulation of Escherichia coli TL+ toxin with an isolated protein of Giardia intestinalis and a synthetic peptide].

PubMed

Jiménez-Cardoso, E; Eligio-García, L; Jiménez-Cardoso, J M; Angeles-Anguiano, E; Tobilla-Mercado, J M; Castañeda, G

2001-01-01

It is know that a protein from Giardia intestinalis works as a substrate for V. cholerae and Escherichia coli. The toxic activity of both activates protein G form intestinal mucosa with a pathogenic activity results. In the present study, the pathogenic activity of subunit A of Vibrio cholerae toxin (ADP-ribosyltranferase) using isolated fragments from: Giardia intestinalis and a synthetic peptide were used as modulators in vivo. Adult Neo Zealand males rabbits with ileal loop were prepared and different mixtures of heat labile enterotoxin obtained from Escherichia coli H10407 and ARF protein isolated by electrofocusing from Giardia intestinalis Portland I were inoculated in the loops. The toxin activity was evaluated by luminal liquid secretion and cyclic AMP concentration in tissues (each loop). ADP ribosyltranferase activity was modulated, due to a decreased of luminal secretion and cAMP in tissues. Such results were seen when synthetic peptide and subunit A from Vibrio cholerae were used. The ADP ribosyltranferase activity of heat labile Escherichia coli and Vibrio cholerae toxins were modified by in vitro and in vivo interaction with ARF protein, which modified pathogenic effect over rabbits intestinal epithelium.

Torsion and volvulus of the transverse and descending colon in a German shepherd dog.

PubMed

Halfacree, Z J; Beck, A L; Lee, K C L; Lipscomb, V J

2006-08-01

A German shepherd dog was presented two months after surgery for correction of acute gastric dilatation volvulus. The dog had been diagnosed with exocrine pancreatic insufficiency. Radiographs revealed marked gaseous distension of one loop of intestine with a generalised increase in intestinal gas content. A 360 degrees anticlockwise rotation of the descending and transverse colon, around the longitudinal axis of the mesocolon, was diagnosed at exploratory coeliotomy. The transverse and descending colon appeared uniformly necrotic and an end-to-end colo-colic resection and anastomosis was performed. The dog initially made satisfactory postoperative progress but was euthanased on the third postoperative day after it developed an intestinal intussusception.

Intestinal obstruction caused by omphalomesenteric duct remnant: usefulness of laparoscopy.

PubMed

Bueno Lledó, J; Serralta Serra, A; Planeéis Roig, M; Dobón Giménez, F; Ibáñez Palacín, F; Rodero Rodero, R

2003-10-01

The anomalies related to omphalomesenteric duct remnant constitute an uncommon cause of intestinal obstruction, of which Meckel"s diverticulum and its variants represent the most important clinical presentation. In most cases they are asymptomatic and usually affect young patients. When symptomatic, they usually present episodes of gastrointestinal bleeding or acute abdomen syndromes caused by strangulation of intestinal loops as a result of fibrous intraabdominal remnants or inflammation produced by the diverticulum. In most cases, the unexpected presence of these alterations makes intraoperative diagnosis necessary. Treatment is surgical and consists in exeresis of the diverticulum or the fibrous band causing the clinical picture. We report two cases of persistence of the vitelline duct resolved by laparoscopic approach.

Absorption-enhancing effects of gemini surfactant on the intestinal absorption of poorly absorbed hydrophilic drugs including peptide and protein drugs in rats.

PubMed

Alama, Tammam; Kusamori, Kosuke; Katsumi, Hidemasa; Sakane, Toshiyasu; Yamamoto, Akira

2016-02-29

In general, the intestinal absorption of small hydrophilic molecules and macromolecules like peptides, after oral administration is very poor. Absorption enhancers are considered to be one of the most promising agents to enhance the intestinal absorption of drugs. In this research, we focused on a gemini surfactant, a new type of absorption enhancer. The intestinal absorption of drugs, with or without sodium dilauramidoglutamide lysine (SLG-30), a gemini surfactant, was examined by an in situ closed-loop method in rats. The intestinal absorption of 5(6)-carboxyfluorescein (CF) and fluorescein isothiocyanate-dextrans (FDs) was significantly enhanced in the presence of SLG-30, such effect being reversible. Furthermore, the calcium levels in the plasma significantly decreased when calcitonin was co-administered with SLG-30, suggestive of the increased intestinal absorption of calcitonin. In addition, no significant increase in the of lactate dehydrogenase (LDH) activity or in protein release from the intestinal epithelium was observed in the presence of SLG-30, suggestive of the safety of this compound. These findings indicate that SLG-30 is an effective absorption-enhancer for improving the intestinal absorption of poorly absorbed drugs, without causing serious damage to the intestinal epithelium. Copyright © 2015 Elsevier B.V. All rights reserved.

The pancreas responds to remote damage and systemic stress by secretion of the pancreatic secretory proteins PSP/regI and PAP/regIII.

PubMed

Reding, Theresia; Palmiere, Cristian; Pazhepurackel, Clinsyjos; Schiesser, Marc; Bimmler, Daniel; Schlegel, Andrea; Süss, Ursula; Steiner, Sabrina; Mancina, Leandro; Seleznik, Gitta; Graf, Rolf

2017-05-02

In patients with infection and sepsis serum levels of Pancreatic Stone protein/regenerating protein I (PSP) are highly elevated. The origin of PSP during these conditions is presumably the pancreas, however, an intestinal origin cannot be excluded. Similarly, pancreatitis-associated protein (PAP) was identified in the pancreas. These proteins were also localized in intestinal organs. Here we aim to elucidate the bio-distribution of PSP and PAP in animal models of sepsis and in healthy humans. PSP and PAP responded to remote lesions in rats although the pancreatic response was much more pronounced than the intestinal. Tissue distribution of PSP demonstrated a 100-fold higher content in the pancreas compared to any other organ while PAP was most abundant in the small intestine. Both proteins responded to CLP or sham operation in the pancreas. PSP also increased in the intestine during CLP. The distribution of PSP and PAP in human tissue mirrored the distribution in the murine models. Distribution of PSP and PAP was visualized by immunohistochemistry. Rats and mice underwent midline laparotomies followed by mobilization of tissue and incision of the pancreatic duct or duodenum. Standard cecum-ligation-puncture (CLP) procedures or sham laparotomies were performed. Human tissue extracts were analyzed for PSP and PAP. The pancreas reacts to remote lesions and septic insults in mice and rats with increased PSP synthesis, while PAP is selectively responsive to septic events. Furthermore, our results suggest that serum PSP in septic patients is predominantly derived through an acute phase response of the pancreas.

Segmental-dependent permeability throughout the small intestine following oral drug administration: Single-pass vs. Doluisio approach to in-situ rat perfusion.

PubMed

Lozoya-Agullo, Isabel; Zur, Moran; Beig, Avital; Fine, Noa; Cohen, Yael; González-Álvarez, Marta; Merino-Sanjuán, Matilde; González-Álvarez, Isabel; Bermejo, Marival; Dahan, Arik

2016-12-30

Intestinal drug permeability is position dependent and pertains to a specific point along the intestinal membrane, and the resulted segmental-dependent permeability phenomenon has been recognized as a critical factor in the overall absorption of drug following oral administration. The aim of this research was to compare segmental-dependent permeability data obtained from two different rat intestinal perfusion approaches: the single-pass intestinal perfusion (SPIP) model and the closed-loop (Doluisio) rat perfusion method. The rat intestinal permeability of 12 model drugs with different permeability characteristics (low, moderate, and high, as well as passively and actively absorbed) was assessed in three small intestinal regions: the upper jejunum, mid-small intestine, and the terminal ileum, using both the SPIP and the Doluisio experimental methods. Excellent correlation was evident between the two approaches, especially in the upper jejunum (R 2 =0.95). Significant regional-dependent permeability was found in half of drugs studied, illustrating the importance and relevance of segmental-dependent intestinal permeability. Despite the differences between the two methods, highly comparable results were obtained by both methods, especially in the medium-high P eff range. In conclusion, the SPIP and the Doluisio method are both equally useful in obtaining crucial segmental-dependent intestinal permeability data. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis of protein in intestinal cells exposed to cholera toxin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, J.W.; Berg, W.D. Jr.; Coppenhaver, D.H.

1987-11-01

The mechanism by which cyclic adenosine monophosphate (AMP), formed by intestinal epithelial cells in response to cholera toxin, ultimately results in alterations in water and electrolyte transport is poorly understood. Several studies have indicated that inhibitors of transcription or translation block much of the transport of ions and water in the intestine and edema formation in tissue elicited by cholera toxin. Data presented in this study confirmed the inhibitory effects of cycloheximide on cholera toxin-induced fluid accumulation in the rabbit intestinal loop model. Neither cycloheximide nor actinomycin D altered the amount of cyclic AMP that accumulated in intestinal cells andmore » Chinese hamster ovary cells exposed to cholera toxin. An increase in (/sup 3/H) leucine incorporation was readily demonstrable in intestinal epithelial cells from rabbits challenged with Vibrio cholerae. Similarly, intestinal epithelial cells incubated with cholera toxin for 4 hr synthesized substantially more protein than controls as determined by relative incorporation of (/sup 35/S) methionine. Most of the new protein synthesized in response to cholera toxin was membrane associated and of high molecular weight. The possible significance of the toxin-induced protein relative to cholera pathogenesis was discussed.« less

K99 antigen-positive enterotoxigenic Escherichia coli from piglets with diarrhea in Sweden.

PubMed Central

Smyth, C J; Olsson, E; Moncalvo, C; Söderlind, O; Orskov, F; Orskov, I

1981-01-01

K88 antigen-negative enterotoxigenic Escherichia coli and non-enterotoxigenic strains isolated from piglets with diarrhea were examined for K99 antigen by agglutination tests after growth on Minca-IsoVitaleX (BBL Microbiology Systems, Cockeysville, Md.) agar medium. Of 64 K88-negative enterotoxigenic strains from as many piglets, 17 were found to be K99 positive. Of these, 10 were Swedish and 7 were of Norwegian origin. All 17 produced heat-stable enterotoxin detectable in the infant mouse assay, but only 2 gave positive ligated loop tests in 3- to 7-week-old piglets. Ligated loop tests in 5- to 12-day-old piglets were positive for each of the 15 K99-positive strains tested. Each of the Swedish K99-positive isolates was from a piglet of lesser than or equal to 7 days of age. One piglet harboring a K99-positive strain also harbored an O141:K88 enterotoxigenic strain producing only heat-stable enterotoxin. Five of the Swedish piglets yielding K99-positive isolates were from dams vaccinated wih a multicomponent bacterial vaccine containing K88 antigen. The K99 strains were O:K:H serotyped. The O serogroups represented were O8, O9, O64, O101, and O140. None of the 101 non-enterotoxigenic porcine isolates, representing 42 serogroups and non-O-groupable and rough strains, was found to be K99 positive. The findings indicate that so-called class 2 or atypical porcine enterotoxigenic E. coli should be routinely examined for the presence of K99 antigen. PMID:7009634

Endothelial binding of beta toxin to small intestinal mucosal endothelial cells in early stages of experimentally induced Clostridium perfringens type C enteritis in pigs.

PubMed

Schumacher, V L; Martel, A; Pasmans, F; Van Immerseel, F; Posthaus, H

2013-07-01

Beta toxin (CPB) is known to be an essential virulence factor in the development of lesions of Clostridium perfringens type C enteritis in different animal species. Its target cells and exact mechanism of toxicity have not yet been clearly defined. Here, we evaluate the suitability of a neonatal piglet jejunal loop model to investigate early lesions of C. perfringens type C enteritis. Immunohistochemically, CPB was detected at microvascular endothelial cells in intestinal villi during early and advanced stages of lesions induced by C. perfringens type C. This was first associated with capillary dilatation and subsequently with widespread hemorrhage in affected intestinal segments. CPB was, however, not demonstrated on intestinal epithelial cells. This indicates a tropism of CPB toward endothelial cells and suggests that CPB-induced endothelial damage plays an important role in the early stages of C. perfringens type C enteritis in pigs.

Retained Capsule Endoscope.

PubMed

Aihole, Jayalaxmi S; Vishnumurthy, G S; Babu, M Narendra

2016-11-15

Capsule endoscopy was invented to visualize the entire small intestine in a non- invasive manner in adults. 1 y, 9 mo-old boy presented with generalized edema for last 3 months. His routine investigations, including the upper gastrointestinal endoscopy, colonoscopy, and contrast enhanced computed tomography scan (CECT) were normal. In view of clinical suspicion of protein losing enteropathy, we planned capsule endoscopy. The capsule was not passed even after 3 weeks. Laparoscopy revealed impacted capsule in a dilated intestinal loop proximal to an ileal stricuture. Capsule endoscopy should be used judiciously in children.

Gastroschisis in the rat model is associated with a delayed maturation of intestinal pacemaker cells and smooth muscle cells.

PubMed

Midrio, P; Faussone-Pellegrini, M S; Vannucchi, M G; Flake, A W

2004-10-01

A pacemaker system is required for peristalsis generation. The interstitial cells of Cajal (ICC) are considered the intestinal pacemaker, and are identified by expression of the c-kit gene--encoded protein. Gastroschisis is characterized by a severe gastrointestinal dysmotility in newborns. In spite of this clinical picture, few studies have focused on smooth muscle cells (SMC) morphology and none on ICC. Therefore, their morphology has been studied in fetuses at term in the rat model of gastroschisis. At 18.5 day's gestation (E18.5), 10 rat fetuses were killed, 10 underwent surgical creation of gastroschisis, and 10 underwent manipulation only. The small intestine of the latter 2 groups was harvested at E21.5. Specimens were processed for H&E, c-kit and actin (alpha smooth muscle antibody [alpha-SMA]) immunohistochemistry, and transmission electron microscopy (TEM). In the controls, SMC were c-kit+ and alpha-SMA+, with labeling intensity increasing by age. At E21.5, some cells around the Auerbach's plexus were more intensely c-kit+, and differentiating ICC were seen under TEM at this level. Gastroschisis fetuses had no c-kit+ cells referable to ICC. In the more damaged loops, SMC were very faintly c-kit+ and alpha-SMA+. Under TEM, there were few differentiated SMC and no presumptive ICC. In the less-damaged loops, SMC were faintly c-kit+ and alpha-SMA+ and had ultrastructural features intermediate between those of E18.5 and E21.5 controls; ICC were very immature. ICC and SMC differentiation is delayed in gastroschisis with the most damaged loops showing the most incomplete picture. These findings might help in understanding the delayed onset of peristalsis and the variable time-course of the recover seen in babies affected by gastroschisis.

Small bowel obstruction by an anomalous congenital band.

PubMed

Nouira, F; Sarrai, N; Charieg, A; Jlidi, S; Chaouachi, B

2012-01-01

We report a case of a 3-year-old boy who presented with symptoms and signs of intestinal obstruction. The patient reported no previous history of abdominal surgery or trauma while clinical and radiographic examinations were not diagnostic. An open laparotomy was subsequently performed and the intraoperative findings were consistent with a congenital band extending from the antimesenteric wall of the jejunum to the root of mesentery. The band was ligated and divided with an uneventful postoperative course. Congenital bands are extremely rare. Their exact incidence is still unknown. This case, therefore, represents an unusual surgical problem in a child in which the diagnosis was clinically unexpected.

Regulators of Intestinal Epithelial Migration in Sepsis.

PubMed

Meng, Mei; Klingensmith, Nathan J; Liang, Zhe; Lyons, John D; Fay, Katherine T; Chen, Ching-Wen; Ford, Mandy L; Coopersmith, Craig M

2018-02-08

The gut is a continuously renewing organ, with cell proliferation, migration and death occurring rapidly under basal conditions. Since the impact of critical illness on cell movement from crypt base to villus tip is poorly understood, the purpose of this study was to determine how sepsis alters enterocyte migration. Wild type, transgenic and knockout mice were injected with 5-bromo-2'deoxyuridine (BrdU) to label cells in S phase before and after the onset of cecal ligation and puncture and were sacrificed at pre-determined endpoints to determine distance proliferating cells migrated up the crypt-villus unit. Enterocyte migration rate was decreased from 24-96 hours following sepsis. BrdU was not detectable on villi 6 days after sham laparotomy, meaning all cells had migrated the length of the gut and been exfoliated into its lumen. However, BrdU positive cells were detectable on villi 10 days after sepsis. Multiple components of gut integrity altered enterocyte migration. Sepsis decreased crypt proliferation, which further slowed enterocyte transit as mice injected with BrdU after the onset of sepsis (decreased proliferation) had slower migration than mice injected with BrdU prior to the onset of sepsis (normal proliferation). Decreasing intestinal apoptosis via gut-specific overexpression of Bcl-2 prevented sepsis-induced slowing of enterocyte migration. In contrast, worsened intestinal hyperpermeability by genetic deletion of JAM-A increased enterocyte migration. Sepsis therefore significantly slows enterocyte migration, and intestinal proliferation, apoptosis and permeability all affect migration time, which can potentially be targeted both genetically and pharmacologically.

A comparative anchorage control study between conventional and self-ligating bracket systems using differential moments.

PubMed

de Almeida, Marcio Rodrigues; Herrero, Francisco; Fattal, Amine; Davoody, Amirparviz R; Nanda, Ravindra; Uribe, Flavio

2013-11-01

To compare the efficiency in anchorage preservation of conventional and self-ligating brackets after the extraction of first maxillary premolars using differential moment mechanics. Thirty-eight patients requiring extraction of maxillary first premolars and maximum anchorage during space closure were evaluated based on bracket type. Group 1, comprising 23 patients, was bonded with preadjusted conventional brackets (CBs) with a slot of 0.022-inch × 0.030-inch. Group 2 comprised 15 patients who were bonded with 0.022 inch preadjusted self-ligating brackets (SLBs). Patients in both groups received a nickel titanium (NiTi) intrusion arch and a 150 g NiTi closing coil spring for separate canine retraction, followed by a continuous mushroom loop archwire to retract the incisors. Lateral cephalograms were available at the start of treatment (T1) and at the completion of space closure (T2). Statistical comparisons were performed with paired and unpaired Student's t-tests. No significant differences were found between the groups in maxillary molars anchorage loss (3.87 ± 1.35 mm and 3.65 ± 1.73 mm for the CB and SLB groups, respectively). Only the mean vertical movement of the tip of the incisor was significantly different between the groups (CB  =  -0.92 ± 1.46 mm; SLB  =  0.56 ± 1.65 mm). There were no significant differences in the amount of anchorage loss of the maxillary first molars between SLB and CB systems during space closure using differential moments.

pH-regulated metal-ligand switching in the HM loop of ATP7A: a new paradigm for metal transfer chemistry.

PubMed

Kline, Chelsey D; Gambill, Benjamin F; Mayfield, Mary; Lutsenko, Svetlana; Blackburn, Ninian J

2016-08-01

Cuproproteins such as PHM and DBM mature in late endosomal vesicles of the mammalian secretory pathway where changes in vesicle pH are employed for sorting and post-translational processing. Colocation with the P1B-type ATPase ATP7A suggests that the latter is the source of copper and supports a mechanism where selectivity in metal transfer is achieved by spatial colocation of partner proteins in their specific organelles or vesicles. In previous work we have suggested that a lumenal loop sequence located between trans-membrane helices TM1 and TM2 of the ATPase, and containing five histidines and four methionines, acts as an organelle-specific chaperone for metallation of the cuproproteins. The hypothesis posits that the pH of the vesicle regulates copper ligation and loop conformation via a mechanism which involves His to Met ligand switching induced by histidine protonation. Here we report the effect of pH on the HM loop copper coordination using X-ray absorption spectroscopy (XAS), and show via selenium substitution of the Met residues that the HM loop undergoes similar conformational switching to that found earlier for its partner PHM. We hypothesize that in the absence of specific chaperones, HM motifs provide a template for building a flexible, pH-sensitive transfer site whose structure and function can be regulated to accommodate the different active site structural elements and pH environments of its partner proteins.

Comparative effectiveness and safety of indomethacin versus ibuprofen for the treatment of patent ductus arteriosus

PubMed Central

Gulack, Brian C.; Laughon, Matthew M.; Clark, Reese H.; Sankar, Meera N.; Hornik, Christoph P.; Smith, P. Brian

2015-01-01

Background Patent ductus arteriosus (PDA) is common in extremely premature infants and associated with increased morbidity and mortality. Medical management of PDA uses either indomethacin or ibuprofen. Despite numerous studies, uncertainty exists as to which drug is safer or more effective; we sought to fill this knowledge gap. Methods We identified infants <28 weeks gestational age discharged from neonatal intensive care units included in the Pediatrix Medical Group Clinical Data Warehouse between 2006 and 2012 who were treated with indomethacin or ibuprofen between postnatal day 2 and 14. Infants treated with both drugs or infants with a congenital malformation were excluded. We used multivariable logistic regression to determine the association of indomethacin versus ibuprofen on clinical outcomes. Results Of 6349 patients who met study criteria, 1177 (19%) received ibuprofen and 5172 (81%) received indomethacin. The median gestational age was 25 weeks (interquartile range 24–26), and 2894 (46%) infants were <750 g at birth. On unadjusted analysis, infants who received ibuprofen had significantly higher incidences of death prior to discharge, surgical ligation of the PDA prior to discharge, death or spontaneous intestinal perforation within 7 days of therapy, death or surgical ligation of the PDA prior to discharge, and an elevated creatinine within 7 days of treatment. However, on multivariable analysis, no significant differences in outcomes were observed (odds ratio for death/PDA ligation for ibuprofen vs. indomethacin = 1.12 [95% CI 0.91–1.39]). Conclusions We observed similar effectiveness and safety profiles for indomethacin and ibuprofen in the medical management of PDA in premature infants. PMID:26386610

Epidermal growth factor improves intestinal integrity and survival in murine sepsis following chronic alcohol ingestion

PubMed Central

Klingensmith, Nathan J.; Yoseph, Benyam P.; Liang, Zhe; Lyons, John D.; Burd, Eileen M.; Margoles, Lindsay M.; Koval, Michael; Ford, Mandy L.; Coopersmith, Craig M.

2016-01-01

Epidermal growth factor (EGF) is a cytoprotective protein that improves survival in preclinical models of sepsis through its beneficial effects on intestinal integrity. Alcohol use disorder worsens intestinal integrity and is associated with increased morbidity and mortality in critical illness. We sought to determine whether chronic alcohol ingestion alters the host response to systemic administration of EGF in sepsis. Six week old FVB/N mice were randomized to receive 20% alcohol or water for 12 weeks. All mice then underwent cecal ligation and puncture (CLP) to induce polymicrobial sepsis. Mice were then randomized to receive either intraperitoneal injection of EGF (150 μg/kg/day) or normal saline. Water-fed mice given EGF mice had decreased seven-day mortality compared to water-fed mice (18% vs. 55%). Alcohol-fed mice given EGF also had decreased seven day mortality compared to alcohol-fed mice (48% vs. 79%). Notably, while systemic EGF improved absolute survival to a similar degree in both water-fed and alcohol-fed mice, mortality was significantly higher in alcohol+EGF mice compared to water+EGF mice. Compared to water-fed septic mice, alcohol-fed septic mice had worsened intestinal integrity with intestinal hyperpermeability, increased intestinal epithelial apoptosis, decreased proliferation and shorter villus length. Systemic administration of EGF to septic alcohol-fed mice decreased intestinal permeability compared to septic alcohol-fed mice given vehicle, with increased levels of the tight junction mediators claudin-5 and JAM-A. Systemic administration of EGF to septic alcohol-fed mice also decreased intestinal apoptosis with an improvement in the Bax/Bcl-2 ratio. EGF also improved both crypt proliferation and villus length in septic alcohol-fed mice. EGF administration resulted in lower levels of both pro- and anti-inflammatory cytokines MCP-1, TNF and IL-10 in alcohol-fed mice. EGF is therefore effective at improving both intestinal integrity and mortality following sepsis in mice with chronic alcohol ingestion. However, the efficacy of EGF in sepsis is blunted in the setting of chronic alcohol ingestion, as intestinal integrity and mortality in alcohol-fed mice given EGF improves animals to levels seen in water-fed mice given vehicle but does not approach levels seen in water-fed mice given EGF. PMID:27465753

Epidermal Growth Factor Improves Intestinal Integrity and Survival in Murine Sepsis Following Chronic Alcohol Ingestion.

PubMed

Klingensmith, Nathan J; Yoseph, Benyam P; Liang, Zhe; Lyons, John D; Burd, Eileen M; Margoles, Lindsay M; Koval, Michael; Ford, Mandy L; Coopersmith, Craig M

2017-02-01

Epidermal growth factor (EGF) is a cytoprotective protein that improves survival in preclinical models of sepsis through its beneficial effects on intestinal integrity. Alcohol use disorder worsens intestinal integrity and is associated with increased morbidity and mortality in critical illness. We sought to determine whether chronic alcohol ingestion alters the host response to systemic administration of EGF in sepsis. Six-week-old FVB/N mice were randomized to receive 20% alcohol or water for 12 weeks. All mice then underwent cecal ligation and puncture to induce polymicrobial sepsis. Mice were then randomized to receive either intraperitoneal injection of EGF (150 μg/kg/day) or normal saline. Water-fed mice given EGF had decreased 7-day mortality compared with water-fed mice (18% vs. 55%). Alcohol-fed mice given EGF also had decreased 7-day mortality compared with alcohol-fed mice (48% vs. 79%). Notably, while systemic EGF improved absolute survival to a similar degree in both water-fed and alcohol-fed mice, mortality was significantly higher in alcohol+EGF mice compared with water+EGF mice. Compared with water-fed septic mice, alcohol-fed septic mice had worsened intestinal integrity with intestinal hyperpermeability, increased intestinal epithelial apoptosis, decreased proliferation and shorter villus length. Systemic administration of EGF to septic alcohol-fed mice decreased intestinal permeability compared with septic alcohol-fed mice given vehicle, with increased levels of the tight junction mediators claudin-5 and JAM-A. Systemic administration of EGF to septic alcohol-fed mice also decreased intestinal apoptosis with an improvement in the Bax/Bcl-2 ratio. EGF also improved both crypt proliferation and villus length in septic alcohol-fed mice. EGF administration resulted in lower levels of both pro- and anti-inflammatory cytokines monocyte chemoattractant protein-1, tumor necrosis factor, and interleukin 10 in alcohol-fed mice. EGF is therefore effective at improving both intestinal integrity and mortality following sepsis in mice with chronic alcohol ingestion. However, the efficacy of EGF in sepsis is blunted in the setting of chronic alcohol ingestion, as intestinal integrity and mortality in alcohol-fed mice given EGF improves animals to levels seen in water-fed mice given vehicle but does not approach levels seen in water-fed mice given EGF.

[Acute pancreatitis and afferent loop syndrome. Case report].

PubMed

Barajas-Fregoso, Elpidio Manuel; Romero-Hernández, Teodoro; Macías-Amezcua, Michel Dassaejv

2013-01-01

The afferent syndrome loop is a mechanic obstruction of the afferent limb before a Billroth II or Roux-Y reconstruction, secondary in most of case to distal or subtotal gastrectomy. Clinical case: Male 76 years old, with antecedent of cholecystectomy, gastric adenocarcinoma six years ago, with subtotal gastrectomy and Roux-Y reconstruction. Beginning a several abdominal pain, nausea and vomiting, abdominal distension, without peritoneal irritation sings. Amylase 1246 U/L, lipase 3381 U/L. Computed Tomography with thickness wall and dilatation of afferent loop, pancreas with diffuse enlargement diagnostic of acute pancreatitis secondary an afferent loop syndrome. The afferent loop syndrome is presented in 0.3%-1% in all cases with Billroth II reconstruction, with a mortality of up to 57%, the obstruction lead accumulation of bile, pancreatic and intestinal secretions, increasing the pressure and resulting in afferent limb, bile conduct and Wirsung conduct dilatation, triggering an inflammatory response that culminates in pancreatic inflammation. The severity of the presentation is related to the degree and duration of the blockage.

Decreased activity and expression of intestinal oligopeptide transporter PEPT1 in rats with hyperthyroidism in vivo.

PubMed

Ashida, Kayoko; Katsura, Toshiya; Saito, Hideyuki; Inui, Ken-ichi

2004-06-01

To examine the effect of thyroid hormone status on PEPT1 in vivo, the activity and expression of PEPT1 in the small intestine were examined in euthyroid and hyperthyroid rats. Hyperthyroidism was induced by treating rats with L-thyroxine (12 mg/L) in the drinking water for 21 days. Transport activity was measured by everted small intestinal preparations and in situ intestinal loop technique. Expressions of PEPT1 mRNA and protein were evaluated by competitive polymerase chain reaction and Western blotting, respectively. The uptake of [14C]glycylsarcosine by everted small intestinal preparations was significantly decreased in hyperthyroid rats, whereas that of methyl-alpha-D-[14C(U)]-glucopyranoside was not altered. Kinetic analysis showed that the Vmax value for [14C]glycylsarcosine uptake was significantly decreased in hyperthyroid rats, whereas the Km value was not affected. The mean portal vein concentrations after intrajejunal administration of [14C]glycylsarcosine were also decreased in hyperthyroid rats. Moreover, hyperthyroidism caused a significant decrease in the expression of PEPT1 mRNA in the small intestine, whereas the expression of Na+/glucose cotransporter (SGLT1) mRNA was not changed. The level of PEPT1 protein was also decreased in the small intestine of hyperthyroid rats. These results indicate that in hyperthyroid rats, the activity and expression of PEPT1 were decreased in the small intestine.

IL-33 promotes an innate immune pathway of intestinal tissue protection dependent on amphiregulin-EGFR interactions.

PubMed

Monticelli, Laurel A; Osborne, Lisa C; Noti, Mario; Tran, Sara V; Zaiss, Dietmar M W; Artis, David

2015-08-25

The barrier surfaces of the skin, lung, and intestine are constantly exposed to environmental stimuli that can result in inflammation and tissue damage. Interleukin (IL)-33-dependent group 2 innate lymphoid cells (ILC2s) are enriched at barrier surfaces and have been implicated in promoting inflammation; however, the mechanisms underlying the tissue-protective roles of IL-33 or ILC2s at surfaces such as the intestine remain poorly defined. Here we demonstrate that, following activation with IL-33, expression of the growth factor amphiregulin (AREG) is a dominant functional signature of gut-associated ILC2s. In the context of a murine model of intestinal damage and inflammation, the frequency and number of AREG-expressing ILC2s increases following intestinal injury and genetic disruption of the endogenous AREG-epidermal growth factor receptor (EGFR) pathway exacerbated disease. Administration of exogenous AREG limited intestinal inflammation and decreased disease severity in both lymphocyte-sufficient and lymphocyte-deficient mice, revealing a previously unrecognized innate immune mechanism of intestinal tissue protection. Furthermore, treatment with IL-33 or transfer of ILC2s ameliorated intestinal disease severity in an AREG-dependent manner. Collectively, these data reveal a critical feedback loop in which cytokine cues from damaged epithelia activate innate immune cells to express growth factors essential for ILC-dependent restoration of epithelial barrier function and maintenance of tissue homeostasis.

Role of interleukin 10 in norfloxacin prevention of luminal free endotoxin translocation in mice with cirrhosis.

PubMed

Gómez-Hurtado, Isabel; Moratalla, Alba; Moya-Pérez, Ángela; Peiró, Gloria; Zapater, Pedro; González-Navajas, José M; Giménez, Paula; Such, José; Sanz, Yolanda; Francés, Rubén

2014-10-01

Bacterial endotoxin is present in patients with advanced cirrhosis and can induce an immunogenic response without an overt infection. Norfloxacin is a gram-negative bactericidal drug able to maintain low endotoxin levels and stimulate IL-10 production. We aimed at investigating the role of IL-10 in decreasing endotoxin absorption in cirrhotic mice treated with norfloxacin. Cirrhosis was induced by carbon tetrachloride or bile duct ligation in wild type and IL10-deficient mice with or without norfloxacin prior to an intragastrical administration of E. coli, K. pneumonia or E. faecalis. Spontaneous and induced bacterial translocation, free endotoxin and cytokine levels were evaluated in mesenteric lymph nodes. Intestinal permeability was followed by fluorimetry and barrier integrity markers were measured in disrupted intestinal samples. The inflammatory-modulating mechanism was characterized in purified intestinal mononuclear cells. Norfloxacin reduced spontaneous and induced MLN positive-cultures in wild type and IL-10-deficient animals. However, reduction of free endotoxin levels was associated with norfloxacin in wild type but not in IL-10-deficient mice. Wild type but not IL-10-deficient mice treated with norfloxacin significantly normalized intestinal permeability and improved gut barrier integrity markers. The toll-like receptor 4-mediated pro-inflammatory milieu was modulated by norfloxacin in a concentration-dependent manner in cultured intestinal mononuclear cells of wild type mice but not of IL-10-deficient mice. The restoration of IL-10 levels in IL-10-deficient animals reactivated the norfloxacin effect on inflammatory-modulation, gut barrier permeability, and luminal endotoxin absorption. Norfloxacin not only reduces gram-negative intestinal flora but also participates in an IL-10-driven modulation of gut barrier permeability, thus reducing luminal free endotoxin absorption in experimental cirrhosis. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Validity evidence for the Fundamentals of Laparoscopic Surgery (FLS) program as an assessment tool: a systematic review.

PubMed

Zendejas, Benjamin; Ruparel, Raaj K; Cook, David A

2016-02-01

The Fundamentals of Laparoscopic Surgery (FLS) program uses five simulation stations (peg transfer, precision cutting, loop ligation, and suturing with extracorporeal and intracorporeal knot tying) to teach and assess laparoscopic surgery skills. We sought to summarize evidence regarding the validity of scores from the FLS assessment. We systematically searched for studies evaluating the FLS as an assessment tool (last search update February 26, 2013). We classified validity evidence using the currently standard validity framework (content, response process, internal structure, relations with other variables, and consequences). From a pool of 11,628 studies, we identified 23 studies reporting validity evidence for FLS scores. Studies involved residents (n = 19), practicing physicians (n = 17), and medical students (n = 8), in specialties of general (n = 17), gynecologic (n = 4), urologic (n = 1), and veterinary (n = 1) surgery. Evidence was most common in the form of relations with other variables (n = 22, most often expert-novice differences). Only three studies reported internal structure evidence (inter-rater or inter-station reliability), two studies reported content evidence (i.e., derivation of assessment elements), and three studies reported consequences evidence (definition of pass/fail thresholds). Evidence nearly always supported the validity of FLS total scores. However, the loop ligation task lacks discriminatory ability. Validity evidence confirms expected relations with other variables and acceptable inter-rater reliability, but other validity evidence is sparse. Given the high-stakes use of this assessment (required for board eligibility), we suggest that more validity evidence is required, especially to support its content (selection of tasks and scoring rubric) and the consequences (favorable and unfavorable impact) of assessment.

Structural determinants of ligand binding in the ternary complex of human ileal bile acid binding protein with glycocholate and glycochenodeoxycholate obtained from solution NMR.

PubMed

Horváth, Gergő; Bencsura, Ákos; Simon, Ágnes; Tochtrop, Gregory P; DeKoster, Gregory T; Covey, Douglas F; Cistola, David P; Toke, Orsolya

2016-02-01

Besides aiding digestion, bile salts are important signal molecules exhibiting a regulatory role in metabolic processes. Human ileal bile acid binding protein (I-BABP) is an intracellular carrier of bile salts in the epithelial cells of the distal small intestine and has a key role in the enterohepatic circulation of bile salts. Positive binding cooperativity combined with site selectivity of glycocholate and glycochenodeoxycholate, the two most abundant bile salts in the human body, make human I-BABP a unique member of the family of intracellular lipid binding proteins. Solution NMR structure of the ternary complex of human I-BABP with glycocholate and glycochenodeoxycholate reveals an extensive network of hydrogen bonds and hydrophobic interactions stabilizing the bound bile salts. Conformational changes accompanying bile salt binding affects four major regions in the protein including the C/D, E/F and G/H loops as well as the helical segment. Most of these protein regions coincide with a previously described network of millisecond time scale fluctuations in the apo protein, a motion absent in the bound state. Comparison of the heterotypic doubly ligated complex with the unligated form provides further evidence of a conformation selection mechanism of ligand entry. Structural and dynamic aspects of human I-BABP-bile salt interaction are discussed and compared with characteristics of ligand binding in other members of the intracellular lipid binding protein family. The coordinates of the 10 lowest energy structures of the human I-BABP : GCDA : GCA complex as well as the distance restraints used to calculate the final ensemble have been deposited in the Brookhaven Protein Data Bank with accession number 2MM3. © 2015 FEBS.

Cholestasis‐induced adaptive remodeling of interlobular bile ducts

PubMed Central

Damle‐Vartak, Amruta; Richter, Beate; Dirsch, Olaf; Dahmen, Uta; Hammad, Seddik

2016-01-01

Cholestasis is a common complication in liver diseases that triggers a proliferative response of the biliary tree. Bile duct ligation (BDL) is a frequently used model of cholestasis in rodents. To determine which changes occur in the three‐dimensional (3D) architecture of the interlobular bile duct during cholestasis, we used 3D confocal imaging, surface reconstructions, and automated image quantification covering a period up to 28 days after BDL. We show a highly reproducible sequence of interlobular duct remodeling, where cholangiocyte proliferation initially causes corrugation of the luminal duct surface, leading to an approximately five‐fold increase in surface area. This is analogous to the function of villi in the intestine or sulci in the brain, where an expansion of area is achieved within a restricted volume. The increase in surface area is further enhanced by duct branching, branch elongation, and loop formation through self‐joining, whereby an initially relatively sparse mesh surrounding the portal vein becomes five‐fold denser through elongation, corrugation, and ramification. The number of connections between the bile duct and the lobular bile canalicular network by the canals of Hering decreases proportionally to the increase in bile duct length, suggesting that no novel connections are established. The diameter of the interlobular bile duct remains constant after BDL, a response that is qualitatively distinct from that of large bile ducts, which tend to enlarge their diameters. Therefore, volume enhancement is only due to net elongation of the ducts. Because curvature and tortuosity of the bile duct are unaltered, this enlargement of the biliary tree is caused by branching and not by convolution. Conclusion: BDL causes adaptive remodeling that aims at optimizing the intraluminal surface area by way of corrugation and branching. (Hepatology 2016;63:951–964) PMID:26610202

Influence of Route of Administration on Immediate and Extended Protection in Rats Immunized with Escherichia coli Heat-Labile Enterotoxin

PubMed Central

Klipstein, Frederick A.; Engert, Richard F.

1980-01-01

The effect of route of administration, dosage, and number of boosts employed during immunization with the polymyxin-release form of Escherichia coli heat-labile (LT) enterotoxin on the degree and duration of protection afforded was evaluated in rats which were challenged by the ligated loop technique. Increasing the boosting dosage by fivefold from 50 to 250 μg resulted in a marked increase in protection against challenge with toxin in rats immunized either just by the parenteral route (i.p./i.p.) or by a parenteral prime, followed by peroral boosts (i.p./p.o.) in rats pretreated with cimetidine to ablate gastric secretions; such was not the case, however, even with a 50-fold increase in dosage in rats immunized just by the peroral route (p.o./p.o.). Four weekly peroral boosts were required to achieve the strongest degree of protection. Increasing the boosting dosage also increased the degree of protection against challenge with viable LT+/ST− and LT+/ST+ strains (ST indicates heat-stable enterotoxin) in rats immunized by the i.p./p.o., but not by the i.p./i.p., route; no protection was evident against an LT−/ST+ strain. Protection was lost within 3 weeks after immunization in rats immunized by the i.p./i.p. route. In contrast, protection was extended over the 3-month observation period in those immunized by the i.p./p.o. route; the degree of protection was enhanced in rats which received an additional boost at 2 months. These observations establish the fact that immunization with LT is similar to that with cholera toxin in that arousal of the local immune intestinal response by means of peroral immunization provides maximal extended protection. PMID:6987180

EFFECT OF SIZE OF INTESTINAL DIVERSIONS IN OBESE PATIENTS WITH METABOLIC SYNDROME SUBMITTED TO GASTRIC BYPASS.

PubMed

Ramos, Rafael Jacques; Mottin, Cláudio Corá; Alves, Letícia Biscaino; Benzano, Daniela; Padoin, Alexandre Vontobel

There is no consensus on the ideal size of intestinal loops in gastric bypass of bariatric surgeries. To evaluate the metabolic outcome of patients submitted to gastric bypass with alimentary and biliopancreatic loops of different sizes. Was conducted a retrospective cohort study in diabetic obese patients (BMI≥35 kg/m2) with metabolic syndrome submitted to gastric bypass. The patients were divided into three groups according to the size of the intestinal loop: group 1, biliopancreatic limb 50 cm length and alimentary limb 100 cm length; group 2 , biliopancreatic limb 50 cm length and alimentary limb 150 cm length; and group 3, biliopancreatic limb 100 cm length and alimentary limb 150 cm length. The effect of gastric bypass with different sizes of intestinal loops in relation to the parameters that define metabolic syndrome was determined. Sixty-three patients were evaluated, and they had a mean age of 44.7±9.4 years. All were diabetics, with 62 (98.4%) being hypertensive and 51 (82.2%) dyslipidemic. The three groups were homogeneous in relation to the variables. In 24 months, there was a remission of systemic arterial hypertension in 65% of patients in group 1, 62.5% in group 2 and 68.4% in group 3. Remission of diabetes occurred in 85% of patients in group 1, 83% in group 2 and 84% in group 3. There was no statistical difference in %LEW between the groups, and waist measurements decreased in a homogeneous way in all groups. The size of loops also had no influence on the improvement in dyslipidemia. Variation in size of intestinal loops does not appear to influence improvement in metabolic syndrome in this group of patients. Não há consenso sobre o tamanho ideal das alças intestinais no bypass gástrico em Y-de-Roux em cirurgias bariátricas. Avaliar os desfechos metabólicos de pacientes submetidos ao bypass gástrico com alça intestinal alimentar e biliopancreática de tamanhos diferentes. Realizou-se coorte retrospectiva em pacientes obesos (IMC≥35 kg/m2) diabéticos com síndrome metabólica submetidos ao bypass gástrico em Y-de-Roux. Foram divididos em três grupos conforme a dimensão das alças intestinais: grupo 1, alça biliopancreática de 50 cm e alça alimentar de 100 cm; grupo 2, alça biliopancreática de 50 cm e alça alimentar de 150 cm e grupo 3, alça biliopancreática de 100 cm e alça alimentar de 150 cm. Foram avaliados os parâmetros que compõem a síndrome metabólica. Incluíram-se 63 pacientes, com média de idade de 44.7±9.4 anos. Todos eram diabéticos, 62 (98.4%) hipertensos e 51 (82.2%) dislipidêmicos. Os três grupos eram homogêneos em relação às variáveis estudadas. Em 24 meses houve remissão da hipertensão arterial sistêmica em 65% do grupo 1, 62.5% no grupo 2 e 68.4% no grupo 3. A remissão do diabete melito tipo 2 ocorreu em 85% dos pacientes do grupo 1, 83% no grupo 2, e 84% no grupo 3. Não houve diferença estatística na porcentagem de perda do excesso de peso entre os grupos e as medidas da cintura abdominal reduziram de forma homogênea em todos os grupos. A dimensão das alças também não influenciou na melhora da dislipidemia. A variação da dimensão das alças intestinais não influenciou na melhora da síndrome metabólica neste grupo de pacientes.

Aryl hydrocarbon receptor and intestinal immunity.

PubMed

Lamas, Bruno; Natividad, Jane M; Sokol, Harry

2018-04-07

Aryl hydrocarbon receptor (AhR) is a member of the basic helix-loop-helix-(bHLH) superfamily of transcription factors, which are associated with cellular responses to environmental stimuli, such as xenobiotics and oxygen levels. Unlike other members of bHLH, AhR is the only bHLH transcription factor that is known to be ligand activated. Early AhR studies focused on understanding the role of AhR in mediating the toxicity and carcinogenesis properties of the prototypic ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In recent years, however, it has become apparent that, in addition to its toxicological involvement, AhR is highly receptive to a wide array of endogenous and exogenous ligands, and that its activation leads to a myriad of key host physiological functions. In this study, we review the current understanding of the functions of AhR in the mucosal immune system with a focus on its role in intestinal barrier function and intestinal immune cells, as well as in intestinal homeostasis.

Role of Cannabinoids in Gastrointestinal Mucosal Defense and Inflammation

PubMed Central

Gyires, Klára; Zádori, Zoltán S.

2016-01-01

Modulating the activity of the endocannabinoid system influences various gastrointestinal physiological and pathophysiological processes, and cannabinoid receptors as well as regulatory enzymes responsible for the synthesis or degradation of endocannabinoids representing potential targets to reduce the development of gastrointestinal mucosal lesions, hemorrhage and inflammation. Direct activation of CB1 receptors by plant-derived, endogenous or synthetic cannabinoids effectively reduces both gastric acid secretion and gastric motor activity, and decreases the formation of gastric mucosal lesions induced by stress, pylorus ligation, nonsteroidal anti-inflammatory drugs (NSAIDs) or alcohol, partly by peripheral, partly by central mechanisms. Similarly, indirect activation of cannabinoid receptors through elevation of endocannabinoid levels by globally acting or peripherally restricted inhibitors of their metabolizing enzymes (FAAH, MAGL) or by inhibitors of their cellular uptake reduces the gastric mucosal lesions induced by NSAIDs in a CB1 receptor-dependent fashion. Dual inhibition of FAAH and cyclooxygenase enzymes induces protection against both NSAID-induced gastrointestinal damage and intestinal inflammation. Moreover, in intestinal inflammation direct or indirect activation of CB1 and CB2 receptors exerts also multiple beneficial effects. Namely, activation of both CB receptors was shown to ameliorate intestinal inflammation in various murine colitis models, to decrease visceral hypersensitivity and abdominal pain, as well as to reduce colitis-associated hypermotility and diarrhea. In addition, CB1 receptors suppress secretory processes and also modulate intestinal epithelial barrier functions. Thus, experimental data suggest that the endocannabinoid system represents a promising target in the treatment of inflammatory bowel diseases, and this assumption is also confirmed by preliminary clinical studies. PMID:26935536

Cell-specific effects of luminal acid, bicarbonate, cAMP, and carbachol on transporter trafficking in the intestine

PubMed Central

Jakab, Robert L.; Collaco, Anne M.

2012-01-01

Changes in intestinal luminal pH affect mucosal ion transport. The aim of this study was to compare how luminal pH and specific second messengers modulate the membrane traffic of four major ion transporters (CFTR, NHE3, NKCC1, and NBCe1) in rat small intestine. Ligated duodenal, jejunal, and ileal segments were infused with acidic or alkaline saline, 8-Br-cAMP, or the calcium agonist carbachol in vivo for 20 min. Compared with untreated intestine, lumen pH was reduced after cAMP or carbachol and increased following HCO3−-saline. Following HCl-saline, lumen pH was restored to control pH levels. All four secretory stimuli resulted in brush-border membrane (BBM) recruitment of CFTR in crypts and villi. In villus enterocytes, CFTR recruitment was coincident with internalization of BBM NHE3 and basolateral membrane recruitment of the bicarbonate transporter NBCe1. Both cAMP and carbachol recruited NKCC1 to the basolateral membrane of enterocytes, while luminal acid or HCO3− retained NKCC1 in intracellular vesicles. Luminal acid resulted in robust recruitment of CFTR and NBCe1 to their respective enterocyte membrane domains in the upper third of the villi; luminal HCO3− induced similar membrane changes lower in the villi. These findings indicate that each stimulus promotes a specific transporter trafficking response along the crypt-villus axis. This is the first demonstration that physiologically relevant secretory stimuli exert their actions in villus enterocytes by membrane recruitment of CFTR and NBCe1 in tandem with NHE3 internalization. PMID:22936272

Cell-specific effects of luminal acid, bicarbonate, cAMP, and carbachol on transporter trafficking in the intestine.

PubMed

Jakab, Robert L; Collaco, Anne M; Ameen, Nadia A

2012-10-15

Changes in intestinal luminal pH affect mucosal ion transport. The aim of this study was to compare how luminal pH and specific second messengers modulate the membrane traffic of four major ion transporters (CFTR, NHE3, NKCC1, and NBCe1) in rat small intestine. Ligated duodenal, jejunal, and ileal segments were infused with acidic or alkaline saline, 8-Br-cAMP, or the calcium agonist carbachol in vivo for 20 min. Compared with untreated intestine, lumen pH was reduced after cAMP or carbachol and increased following HCO(3)(-)-saline. Following HCl-saline, lumen pH was restored to control pH levels. All four secretory stimuli resulted in brush-border membrane (BBM) recruitment of CFTR in crypts and villi. In villus enterocytes, CFTR recruitment was coincident with internalization of BBM NHE3 and basolateral membrane recruitment of the bicarbonate transporter NBCe1. Both cAMP and carbachol recruited NKCC1 to the basolateral membrane of enterocytes, while luminal acid or HCO(3)(-) retained NKCC1 in intracellular vesicles. Luminal acid resulted in robust recruitment of CFTR and NBCe1 to their respective enterocyte membrane domains in the upper third of the villi; luminal HCO(3)(-) induced similar membrane changes lower in the villi. These findings indicate that each stimulus promotes a specific transporter trafficking response along the crypt-villus axis. This is the first demonstration that physiologically relevant secretory stimuli exert their actions in villus enterocytes by membrane recruitment of CFTR and NBCe1 in tandem with NHE3 internalization.

A RADIOAUTOGRAPHIC STUDY OF GLYCERIDE SYNTHESIS IN VIVO DURING INTESTINAL ABSORPTION OF FATS AND LABELED GLUCOSE

PubMed Central

Jersild, Ralph A.

1966-01-01

Radioautography was used to detect the synthesis of labeled glycerides in intestinal absorptive cells following injections of fatty chyme and glucose-6-H3 into ligated segments of upper jejunum of fasting rats. Absorption intervals ranged from 2 to 20 min. Labeling is evident throughout the cells in as short a time as 2 min. Most grains are present over droplets of absorbed fat beginning with those in the endoplasmic reticulum immediately subjacent to the terminal web. With longer absorption periods, frequent grains are present over accumulations of fat droplets in the Golgi cisternae and intercellular spaces. A similar pattern of grains is seen following absorption of either linoleic acid or safflower oil. By comparison, considerably less label is present in the cells when the fat is extracted with alcohol prior to radioautographic procedures, or when labeled glucose alone is absorbed. A significant incorporation of glucose label into newly synthesized glycerides is indicated and confirmed by scintillation counts on saponified lipid extracts. The grain distribution implies an involvement of the extreme apical endoplasmic reticulum in this synthesis. PMID:5971642

Upper Extremity Steal Syndrome Is Associated with Atherosclerotic Burden and Access Configuration.

PubMed

Kudlaty, Elizabeth A; Kendrick, Daniel E; Allemang, Matthew T; Kashyap, Vikram S; Wong, Virginia L

2016-08-01

Clinically significant steal syndrome occurs in a subset of dialysis patients with arteriovenous (AV) access. Factors associated with steal are poorly understood. Severe symptoms require access revision or sacrifice, potentially jeopardizing access options. Our objective was to review our dialysis access experience to identify factors associated with significant steal syndrome. We reviewed all adult patients undergoing their first permanent upper extremity access, AV fistula (AVF) or AV graft (AVG), between January 2008 and July 2011 at a single center. Medical, demographic, and access characteristics were collected from our electronic medical record and a local dialysis center's database. Patients who required correction of steal syndrome were compared with the larger access cohort. Statistical analysis included Fisher's exact test and χ(2) for noncontinuous variables and unpaired t-test for continuous variables. Of the 303 patients, 15 required correction for steal syndrome (8 of 232 AVF and 7 of 71 AVG). Eight were ligated; 2 were initially banded, then ligated; and 5 underwent distal revascularization with interval ligation. Coronary artery disease was more prevalent in steal syndrome patients (66.7% vs. 25%, P = 0.001); the same was found with peripheral arterial disease (40% vs. 13.8%, P = 0.02). Furthermore, more patients with steal syndrome were on clopidogrel for cardiovascular reasons (40% vs. 9%, P = 0.002). Steal syndrome only developed with AVF and AVG using brachial artery inflow. No cases of steal syndrome arose from radial/ulnar inflow (P = 0.03). All AVG with steal syndrome had a straight configuration; no looped AVG developed steal (P = 0.02). Other patient characteristics such as age, sex, race, hypertension, diabetes mellitus, congestive heart failure, cerebrovascular accident, cause of end-stage renal disease, and other medication history were not different between groups. Clinically significant steal syndrome is associated with disease in coronary and peripheral arterial beds. In addition, the use of brachial artery inflow and straight AVG configuration is associated with steal syndrome. Consideration should be given to construction of access using smaller forearm arteries and looped AVG configuration in patients with high risk for steal. In addition, such patients may require more vigilant monitoring for development of steal after access construction. Copyright © 2016 Elsevier Inc. All rights reserved.

Increased intestinal absorption in the rat caused by sodium lauryl sulphate, and its possible relation to the cAMP system.

PubMed

Briseid, G; Briseid, K; Kirkevold, K

1976-01-01

The increases in the absorption of ouabain, phenolsulphonphthalein and pralidoxime caused by 17 mM sodium lauryl sulphate (SLS) from jejunal loops of anaesthetized rats were significantly reduced if sodium and chloride (Briseid et al., 1974) or chloride and bicarbonate were replaced by other ions in the loop fluid. Separate substitutions of sodium, chloride of bicarbonate did not significantly alter the SLS-caused absorption, except that the substitution of choline for sodium reduced the absorption of pralidoxime, both in the presence and in the absence of SLS. The increases in the absorption of phenolsulphonphthalein and pralidoxime caused by SLS were potentiated by theophylline (25 mM) and reduced by imidazole (25 mM). The addition of dibutyryl cyclic AMP (2.5 mM) to the loop fluid increased this absorption of the test substances. This effect was reduced by imidazole, but under the experimental conditions it was not potentiated by theophylline. Determinations of cyclic AMP in the rat intestinal mucosa showed that the level of this substance was significantly higher in the presence than in the absence of SLS. The experimental conditions were as described for the absorption experiments. It is concluded that the data obtained support the idea of an increased level of cyclic AMP as the main basis for the effect of SLS on the absorption.

NF-κB regulates neuronal ankyrin-G via a negative feedback loop.

PubMed

König, Hans-Georg; Schwamborn, Robert; Andresen, Silke; Kinsella, Sinéad; Watters, Orla; Fenner, Beau; Prehn, Jochen H M

2017-02-09

The axon initial segment (AIS) is a neuronal compartment defined by ankyrin-G expression. We here demonstrate that the IKK-complex co-localizes and interacts with the cytoskeletal anchor protein ankyrin-G in immunoprecipitation and proximity-ligation experiments in cortical neurons. Overexpression of the 270 kDa variant of ankyrin-G suppressed, while gene-silencing of ankyrin-G expression increased nuclear factor-κB (NF-κB) activity in primary neurons, suggesting that ankyrin-G sequesters the transcription factor in the AIS. We also found that p65 bound to the ank3 (ankyrin-G) promoter sequence in chromatin immunoprecipitation analyses thereby increasing ank3 expression and ankyrin-G levels at the AIS. Gene-silencing of p65 or ankyrin-G overexpression suppressed ank3 reporter activity. Collectively these data demonstrate that p65/NF-κB controls ankyrin-G levels via a negative feedback loop, thereby linking NF-κB signaling with neuronal polarity and axonal plasticity.

Transcript Lifetime Is Balanced between Stabilizing Stem-Loop Structures and Degradation-Promoting Polyadenylation in Plant Mitochondria

PubMed Central

Kuhn, Josef; Tengler, Ulrike; Binder, Stefan

2001-01-01

To determine the influence of posttranscriptional modifications on 3′ end processing and RNA stability in plant mitochondria, pea atp9 and Oenothera atp1 transcripts were investigated for the presence and function of 3′ nonencoded nucleotides. A 3′ rapid amplification of cDNA ends approach initiated at oligo(dT)-adapter primers finds the expected poly(A) tails predominantly attached within the second stem or downstream of the double stem-loop structures at sites of previously mapped 3′ ends. Functional studies in a pea mitochondrial in vitro processing system reveal a rapid removal of the poly(A) tails up to termini at the stem-loop structure but little if any influence on further degradation of the RNA. In contrast 3′ poly(A) tracts at RNAs without such stem-loop structures significantly promote total degradation in vitro. To determine the in vivo identity of 3′ nonencoded nucleotides more accurately, pea atp9 transcripts were analyzed by a direct anchor primer ligation-reverse transcriptase PCR approach. This analysis identified maximally 3-nucleotide-long nonencoded extensions most frequently of adenosines combined with cytidines. Processing assays with substrates containing homopolymer stretches of different lengths showed that 10 or more adenosines accelerate RNA processivity, while 3 adenosines have no impact on RNA life span. Thus polyadenylation can generally stimulate the decay of RNAs, but processivity of degradation is almost annihilated by the stabilizing effect of the stem-loop structures. These antagonistic actions thus result in the efficient formation of 3′ processed and stable transcripts. PMID:11154261

Mechanisms of intestinal barrier dysfunction in sepsis

PubMed Central

Yoseph, Benyam P.; Klingensmith, Nathan J.; Liang, Zhe; Breed, Elise R.; Burd, Eileen M.; Mittal, Rohit; Dominguez, Jessica A.; Petrie, Benjamin; Ford, Mandy L.; Coopersmith, Craig M.

2016-01-01

Intestinal barrier dysfunction is thought to contribute to the development of multiple organ dysfunction syndrome in sepsis. Although there are similarities in clinical course following sepsis, there are significant differences in the host response depending on the initiating organism and time course of the disease, and pathways of gut injury vary widely in different preclinical models of sepsis. The purpose of this study was to determine whether the timecourse and mechanisms of intestinal barrier dysfunction are similar in disparate mouse models of sepsis with similar mortalities. FVB/N mice were randomized to receive cecal ligation and puncture (CLP) or sham laparotomy, and permeability was measured to fluoresceinisothiocyanate conjugated-dextran (FD-4) six to 48 hours later. Intestinal permeability was elevated following CLP at all timepoints measured, peaking at six to 12 hours. Tight junction proteins claudin 1, 2, 3, 4, 5, 7, 8, 13 and 15, JAM-A, occludin, and ZO-1 were than assayed by Western blot, real-time polymerase chain reaction, and immunohistochemistry 12 hours after CLP to determine potential mechanisms underlying increases in intestinal permeability. Claudin 2 and JAM-A were increased by sepsis whereas claudin-5 and occludin were decreased by sepsis. All other tight junction proteins were unchanged. A further timecourse experiment demonstrated that alterations in claudin-2 and occludin were detectable as early as 1 hour after the onset of sepsis. Similar experiments were then performed in a different group of mice subjected to Pseudomonas aeruginosa pneumonia. Mice with pneumonia had an increase in intestinal permeability similar in timecourse and magnitude to that seen in CLP. Similar changes in tight junction proteins were seen in both models of sepsis although mice subjected to pneumonia also had a marked decrease in ZO-1 not seen in CLP. These results indicate that two disparate, clinically relevant models of sepsis induce a significant increase in intestinal permeability mediated through a common pathway involving alterations in claudin 2, claudin 5, JAM-A and occludin although model-specific differences in ZO-1 were also identified. PMID:27299587

Mechanisms of Intestinal Barrier Dysfunction in Sepsis.

PubMed

Yoseph, Benyam P; Klingensmith, Nathan J; Liang, Zhe; Breed, Elise R; Burd, Eileen M; Mittal, Rohit; Dominguez, Jessica A; Petrie, Benjamin; Ford, Mandy L; Coopersmith, Craig M

2016-07-01

Intestinal barrier dysfunction is thought to contribute to the development of multiple organ dysfunction syndrome in sepsis. Although there are similarities in clinical course following sepsis, there are significant differences in the host response depending on the initiating organism and time course of the disease, and pathways of gut injury vary widely in different preclinical models of sepsis. The purpose of this study was to determine whether the timecourse and mechanisms of intestinal barrier dysfunction are similar in disparate mouse models of sepsis with similar mortalities. FVB/N mice were randomized to receive cecal ligation and puncture (CLP) or sham laparotomy, and permeability was measured to fluoresceinisothiocyanate conjugated-dextran (FD-4) six to 48 h later. Intestinal permeability was elevated following CLP at all timepoints measured, peaking at 6 to 12 h. Tight junction proteins claudin 1, 2, 3, 4, 5, 7, 8, 13, and 15, Junctional Adhesion Molecule-A (JAM-A), occludin, and ZO-1 were than assayed by Western blot, real-time polymerase chain reaction, and immunohistochemistry 12 h after CLP to determine potential mechanisms underlying increases in intestinal permeability. Claudin 2 and JAM-A were increased by sepsis, whereas claudin-5 and occludin were decreased by sepsis. All other tight junction proteins were unchanged. A further timecourse experiment demonstrated that alterations in claudin-2 and occludin were detectable as early as 1 h after the onset of sepsis. Similar experiments were then performed in a different group of mice subjected to Pseudomonas aeruginosa pneumonia. Mice with pneumonia had an increase in intestinal permeability similar in timecourse and magnitude to that seen in CLP. Similar changes in tight junction proteins were seen in both models of sepsis although mice subjected to pneumonia also had a marked decrease in ZO-1 not seen in CLP. These results indicate that two disparate, clinically relevant models of sepsis induce a significant increase in intestinal permeability mediated through a common pathway involving alterations in claudin 2, claudin 5, JAM-A, and occludin although model-specific differences in ZO-1 were also identified.

A complication to be aware of: hyperkalaemia following propranolol therapy for an infant with intestinal haemangiomatozis.

PubMed

Belen, Burcu; Oguz, Aynur; Okur, Arzu; Dalgic, Buket

2014-05-19

Infantile haemangiomas, benign vascular tumours seen in 4-10% of infants are characterised by their spontaneous remission following a 3-9 month period of dynamic growth. Propranolol has been reported to be used as a successful treatment of severe symptomatic infantile haemangiomas. Hyperkalaemia has not been recognised as a serious effect of propranolol since recently. Here, we would like to portray a 2-year-old male patient with intestinal haemangiomatosis who presented with severe hyperkalaemia and was successfully managed with hydration, loop diuretics, potassium binding granules, inhaler β-2 agonists and insulin. To date, this is the first case of intestinal haemangiomatosis complicated with severe hyperkalaemia. Our case suggested the idea of close monitorisation of potassium levels as well as haemodynamic status at the initialisation of the propranolol treatment. 2014 BMJ Publishing Group Ltd.

A complication to be aware of: hyperkalaemia following propranolol therapy for an infant with intestinal haemangiomatozis

PubMed Central

Belen, Burcu; Oguz, Aynur; Okur, Arzu; Dalgic, Buket

2014-01-01

Infantile haemangiomas, benign vascular tumours seen in 4–10% of infants are characterised by their spontaneous remission following a 3–9 month period of dynamic growth. Propranolol has been reported to be used as a successful treatment of severe symptomatic infantile haemangiomas. Hyperkalaemia has not been recognised as a serious effect of propranolol since recently. Here, we would like to portray a 2-year-old male patient with intestinal haemangiomatosis who presented with severe hyperkalaemia and was successfully managed with hydration, loop diuretics, potassium binding granules, inhaler β-2 agonists and insulin. To date, this is the first case of intestinal haemangiomatosis complicated with severe hyperkalaemia. Our case suggested the idea of close monitorisation of potassium levels as well as haemodynamic status at the initialisation of the propranolol treatment. PMID:24842358

Clostridium perfringens epsilon toxin increases the small intestinal permeability in mice and rats.

PubMed

Goldstein, Jorge; Morris, Winston E; Loidl, César Fabián; Tironi-Farinati, Carla; Tironi-Farinatti, Carla; McClane, Bruce A; Uzal, Francisco A; Fernandez Miyakawa, Mariano E

2009-09-18

Epsilon toxin is a potent neurotoxin produced by Clostridium perfringens types B and D, an anaerobic bacterium that causes enterotoxaemia in ruminants. In the affected animal, it causes oedema of the lungs and brain by damaging the endothelial cells, inducing physiological and morphological changes. Although it is believed to compromise the intestinal barrier, thus entering the gut vasculature, little is known about the mechanism underlying this process. This study characterizes the effects of epsilon toxin on fluid transport and bioelectrical parameters in the small intestine of mice and rats. The enteropooling and the intestinal loop tests, together with the single-pass perfusion assay and in vitro and ex vivo analysis in Ussing's chamber, were all used in combination with histological and ultrastructural analysis of mice and rat small intestine, challenged with or without C. perfringens epsilon toxin. Luminal epsilon toxin induced a time and concentration dependent intestinal fluid accumulation and fall of the transepithelial resistance. Although no evident histological changes were observed, opening of the mucosa tight junction in combination with apoptotic changes in the lamina propria were seen with transmission electron microscopy. These results indicate that C. perfringens epsilon toxin alters the intestinal permeability, predominantly by opening the mucosa tight junction, increasing its permeability to macromolecules, and inducing further degenerative changes in the lamina propria of the bowel.

Ion channel TRPV1-dependent activation of PTP1B suppresses EGFR-associated intestinal tumorigenesis

PubMed Central

de Jong, Petrus R.; Takahashi, Naoki; Harris, Alexandra R.; Lee, Jihyung; Bertin, Samuel; Jeffries, James; Jung, Michael; Duong, Jen; Triano, Amy I.; Lee, Jongdae; Niv, Yaron; Herdman, David S.; Taniguchi, Koji; Kim, Chang-Whan; Dong, Hui; Eckmann, Lars; Stanford, Stephanie M.; Bottini, Nunzio; Corr, Maripat; Raz, Eyal

2014-01-01

The intestinal epithelium has a high rate of turnover, and dysregulation of pathways that regulate regeneration can lead to tumor development; however, the negative regulators of oncogenic events in the intestinal epithelium are not fully understood. Here we identified a feedback loop between the epidermal growth factor receptor (EGFR), a known mediator of proliferation, and the transient receptor potential cation channel, subfamily V, member 1 (TRPV1), in intestinal epithelial cells (IECs). We found that TRPV1 was expressed by IECs and was intrinsically activated upon EGFR stimulation. Subsequently, TRPV1 activation inhibited EGFR-induced epithelial cell proliferation via activation of Ca2+/calpain and resulting activation of protein tyrosine phosphatase 1B (PTP1B). In a murine model of multiple intestinal neoplasia (ApcMin/+ mice), TRPV1 deficiency increased adenoma formation, and treatment of these animals with an EGFR kinase inhibitor reversed protumorigenic phenotypes, supporting a functional association between TRPV1 and EGFR signaling in IECs. Administration of a TRPV1 agonist suppressed intestinal tumorigenesis in ApcMin/+ mice, similar to — as well as in conjunction with — a cyclooxygenase-2 (COX-2) inhibitor, which suggests that targeting both TRPV1 and COX-2 has potential as a therapeutic approach for tumor prevention. Our findings implicate TRPV1 as a regulator of growth factor signaling in the intestinal epithelium through activation of PTP1B and subsequent suppression of intestinal tumorigenesis. PMID:25083990

Small intestinal bacterial overgrowth syndrome

PubMed Central

Bures, Jan; Cyrany, Jiri; Kohoutova, Darina; Förstl, Miroslav; Rejchrt, Stanislav; Kvetina, Jaroslav; Vorisek, Viktor; Kopacova, Marcela

2010-01-01

Human intestinal microbiota create a complex polymicrobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO). SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract. There are several endogenous defence mechanisms for preventing bacterial overgrowth: gastric acid secretion, intestinal motility, intact ileo-caecal valve, immunoglobulins within intestinal secretion and bacteriostatic properties of pancreatic and biliary secretion. Aetiology of SIBO is usually complex, associated with disorders of protective antibacterial mechanisms (e.g. achlorhydria, pancreatic exocrine insufficiency, immunodeficiency syndromes), anatomical abnormalities (e.g. small intestinal obstruction, diverticula, fistulae, surgical blind loop, previous ileo-caecal resections) and/or motility disorders (e.g. scleroderma, autonomic neuropathy in diabetes mellitus, post-radiation enteropathy, small intestinal pseudo-obstruction). In some patients more than one factor may be involved. Symptoms related to SIBO are bloating, diarrhoea, malabsorption, weight loss and malnutrition. The gold standard for diagnosing SIBO is still microbial investigation of jejunal aspirates. Non-invasive hydrogen and methane breath tests are most commonly used for the diagnosis of SIBO using glucose or lactulose. Therapy for SIBO must be complex, addressing all causes, symptoms and complications, and fully individualised. It should include treatment of the underlying disease, nutritional support and cyclical gastro-intestinal selective antibiotics. Prognosis is usually serious, determined mostly by the underlying disease that led to SIBO. PMID:20572300

Chronic Intestinal Pseudo-obstruction: Clinical and Manometric Characteristics in the Chilean Population

PubMed Central

de Arce, Edith Pérez; Landskron, Glauben; Hirsch, Sandra; Defilippi, Carlos; Madrid, Ana María

2017-01-01

Background/Aims Chronic intestinal pseudo-obstruction (CIPO) is a rare syndrome characterized by a failure of the propulsion of intraluminal contents and recurrent symptoms of partial bowel obstruction in the absence of mechanical obstruction. Regional variations of the intestinal compromise have been described. Intestinal manometry can indicate the pathophysiology and prognosis. Our objective is to establish the demographic and clinical characteristics of group Chilean patients and analyze the motility of the small intestine and its prognostic value. Methods Patients with symptoms of intestinal pseudo-obstruction with dilated bowel loops were included, in all of whom a manometry of the small intestine was performed using perfused catheters. Results Of the 64 patients included, 51 women (average age 41.5 ± 17.6 years), 54 primary and 10 secondary CIPO were included. Dilatation of the small intestine was the only finding in 38 patients; in the remaining, the compromise was associated with other segments, primarily the colon. Forty-nine patients underwent 65 surgeries, mainly exploratory laparotomies and colectomies. Intestinal manometry was performed on all patients; 4 “patterns” were observed: neuropathic (n = 26), myopathic (n = 3), mixed (n = 24), and a group without motor activity (n = 11). The most relevant findings were the complex migrating motor disorders and decreased frequency and propagation of contractions. The 9 patients who died had a severe myopathic compromise. Conclusions In our series, isolated small bowel compromise was the most common disorder. Neuropathic motor compromise was observed in most of the patients. Mortality was associated with severe myopathic compromise. PMID:27669829

Ontogenetic development of intestinal length and relationships to diet in an Australasian fish family (Terapontidae)

PubMed Central

2013-01-01

Background One of the most widely accepted ecomorphological relationships in vertebrates is the negative correlation between intestinal length and proportion of animal prey in diet. While many fish groups exhibit this general pattern, other clades demonstrate minimal, and in some cases contrasting, associations between diet and intestinal length. Moreover, this relationship and its evolutionary derivation have received little attention from a phylogenetic perspective. This study documents the phylogenetic development of intestinal length variability, and resultant correlation with dietary habits, within a molecular phylogeny of 28 species of terapontid fishes. The Terapontidae (grunters), an ancestrally euryhaline-marine group, is the most trophically diverse of Australia’s freshwater fish families, with widespread shifts away from animal-prey-dominated diets occurring since their invasion of fresh waters. Results Description of ontogenetic development of intestinal complexity of terapontid fishes, in combination with ancestral character state reconstruction, demonstrated that complex intestinal looping (convolution) has evolved independently on multiple occasions within the family. This modification of ontogenetic development drives much of the associated interspecific variability in intestinal length evident in terapontids. Phylogenetically informed comparative analyses (phylogenetic independent contrasts) showed that the interspecific differences in intestinal length resulting from these ontogenetic developmental mechanisms explained ~65% of the variability in the proportion of animal material in terapontid diets. Conclusions The ontogenetic development of intestinal complexity appears to represent an important functional innovation underlying the extensive trophic differentiation seen in Australia’s freshwater terapontids, specifically facilitating the pronounced shifts away from carnivorous (including invertebrates and vertebrates) diets evident across the family. The capacity to modify intestinal morphology and physiology may also be an important facilitator of trophic diversification during other phyletic radiations. PMID:23441994

Single paracostal approach to thoracic duct and cisterna chyli: experimental study and case series.

PubMed

Staiger, Benjamin A; Stanley, Bryden J; McAnulty, Jonathan F

2011-10-01

To-determine the feasibility of a single paracostal abdominal approach for thoracic duct ligation (TDL) and cisterna chyli ablation (CCA) in dogs with chylothorax. Observational study and prospective case series. Normal dogs (n = 5) and dogs with chylothorax (n = 8). A single paracostal approach with transdiaphragmatic extension for TDL and CCA was developed experimentally (n = 5) and used in 8 clinical cases with subtotal pericardectomy (SPE) performed in 4 dogs. Surgery time, complications, hospitalization time, outcome, and follow-up of clinical cases were recorded. Exposure of relevant anatomy was excellent; vital lymphatic staining facilitated identification of lymphatic structures. In clinical cases, mean surgery time for TDL + CCA was 136 minutes. Mean hospitalization time was 3.1 days. Seven of 8 cases survived, with 1 dog dying of heart failure shortly after discharge. One dog required a second (left) paracostal approach to ligate 2 more lymphatic vessels. On follow-up (median, 7 months; range, 2-20 months), there was complete resolution of chylothorax in 6 dogs. A single paracostal approach provides excellent exposure of cisterna chyli, caudal thoracic duct, and intestinal lymphatics. This approach eliminates the need for repositioning during combined TDL + CCA procedures and avoids an intercostal thoracotomy. © Copyright 2011 by The American College of Veterinary Surgeons.

Use of monoclonal antibodies developed against chicken coccidia (Eimeria) to study invasion and development of Eimeria reichenowi in Florida sandhill cranes (Grus canadensis).

PubMed

Augustine, P; Olsen, G; Danforth, H; Gee, G; Novilla, M

2001-03-01

Eimeria gruis and Eimeria reichenowi are common coccidial parasites of a number of species of cranes. Until recently, little was known about either the site for invasion or the dynamics of early development of the crane coccidia because of the difficulty of identifying sporozoites and early developmental stages of these parasites by conventional staining methods. In the present study, monoclonal antibodies (MAbs) elicited against Eimeria spp. of chickens and turkeys were found to cross-react with sporozoites and developmental stages of E. reichenowi in the tissues of Florida sandhill cranes (Grus canadensis). With these Mabs, E. reichenowi sporozoites were found in specimens taken at 6 hr postinoculation (PI) from just proximal to Meckel's diverticulum in the jejunum to the ileocecal juncture. Fewer were found in the ceca and rectum and none in the duodenal loop. At 24 hr PI, there were markedly fewer sporozoites and their location had shifted to the duodenum. No stages were seen in intestinal cells at 5 days PI (DPI), but trophozoites had developed in the liver and spleen. At 10 DPI, sexual stages were detected in the intestine from the duodenal loop through Meckel's diverticulum but not in other organs. By 14 DPI, numerous developmental stages were detected in the intestine (ceca and jejunum), liver, and lungs but not in the heart, kidney, or brain. The number, location, and maturity of the stages in the ceca differed markedly from those in the jejunum.

Use of monoclonal antibodies developed against chicken coccidia (Eimeria) to study invasion and development of Eimeria reichenowi in Florida sandhill cranes (Grus canadensis)

USGS Publications Warehouse

Augustine, P.C.; Olsen, Glenn H.; Danforth, H.D.; Gee, G.F.; Novilla, M.

2001-01-01

Eimeria gruis and Eimeria reichenowi are common coccidial parasites of a number of species of cranes. Until recently, little was known about either the site for invasion or the dynamics of early development of the crane coccidia because of the difficulty of identifying sporozoites and early developmental stages of these parasites by conventional staining methods. In the present study, monoclonal antibodies (MAbs) elicited against Eimeria spp. of chickens and turkeys were found to cross-react with sporozoites and developmental stages of E. reichenowi in the tissues of Florida sandhill cranes (Grus canadensis). With these Mabs, E. reichenowi sporozoites were found in specimens taken at 6 hr postinoculation (PI) from just proximal to Meckel's diverticulum in the jejunum to the ileocecal juncture. Fewer were found in the ceca and rectum and none in the duodenal loop. At 24 hr PI, there were markedly fewer sporozoites and their location had shifted to the duodenum. No stages were seen in intestinal cells at 5 days PI (DPI), but trophozoites had developed in the liver and spleen. At 10 DPI, sexual stages were detected in the intestine from the duodenal loop through Meckel's diverticulum but not in other organs. By 14 DPI, numerous developmental stages were detected in the intestine (ceca and jejunum), liver, and lungs but not in the heart, kidney, or brain. The number, location, and maturity of the stages in the ceca differed markedly from those in the jejunum.

Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice

PubMed Central

Zhou, Yu-Kun; Qin, Huan-Long; Zhang, Ming; Shen, Tong-Yi; Chen, Hong-Qi; Ma, Yan-Lei; Chu, Zhao-Xin; Zhang, Peng; Liu, Zhi-Hua

2012-01-01

AIM: To investigate the mechanisms of Lactobacillus plantarum (L. plantarum) action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats. METHODS: Forty rats were randomly divided into groups of sham-operation, bile duct ligation (BDL), BDL + L. plantarum, BDL + internal biliary drainage (IBD), and BDL + IBD + L. plantarum. Ten days after L. plantarum administration, blood and ileal samples were collected from the rats for morphological examination, and intestinal barrier function, liver function, intestinal oxidative stress and protein kinase C (PKC) activity measurement. The distribution and expression of the PKC and tight junction (TJ) proteins, such as occludin, zonula occludens-1, claudin-1, claudin-4, junction adhesion molecule-A and F-actin, were examined by confocal laser scanning microscopy, immunohistochemistry, Western blotting, real-time fluorescent quantitative polymerase chain reaction assay. RESULTS: L. plantarum administration substantially restored gut barrier, decreased enterocyte apoptosis, improved intestinal oxidative stress, promoted the activity and expression of protein kinase (BDL vs BDL + L. plantarum, 0.295 ± 0.007 vs 0.349 ± 0.003, P < 0.05; BDL + IBD vs BDL + IBD + L. plantarum, 0.407 ± 0.046 vs 0.465 ± 0.135, P < 0.05), and particularly enhanced the expression and phosphorylation of TJ proteins in the experimental obstructive jaundice (BDL vs BDL + L. plantarum, 0.266 ± 0.118 vs 0.326 ± 0.009, P < 0.05). The protective effect of L. plantarum was more prominent after internal biliary drainage ( BDL + IBD vs BDL + IBD + L. plantarum, 0.415 ± 0.105 vs 0.494 ± 0.145, P < 0.05). CONCLUSION: L. plantarum can decrease intestinal epithelial cell apoptosis, reduce oxidative stress, and prevent TJ disruption in biliary obstruction by activating the PKC pathway. PMID:22912548

Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice.

PubMed

Zhou, Yu-Kun; Qin, Huan-Long; Zhang, Ming; Shen, Tong-Yi; Chen, Hong-Qi; Ma, Yan-Lei; Chu, Zhao-Xin; Zhang, Peng; Liu, Zhi-Hua

2012-08-14

To investigate the mechanisms of Lactobacillus plantarum (L. plantarum) action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats. Forty rats were randomly divided into groups of sham-operation, bile duct ligation (BDL), BDL + L. plantarum, BDL + internal biliary drainage (IBD), and BDL + IBD + L. plantarum. Ten days after L. plantarum administration, blood and ileal samples were collected from the rats for morphological examination, and intestinal barrier function, liver function, intestinal oxidative stress and protein kinase C (PKC) activity measurement. The distribution and expression of the PKC and tight junction (TJ) proteins, such as occludin, zonula occludens-1, claudin-1, claudin-4, junction adhesion molecule-A and F-actin, were examined by confocal laser scanning microscopy, immunohistochemistry, Western blotting, real-time fluorescent quantitative polymerase chain reaction assay. L. plantarum administration substantially restored gut barrier, decreased enterocyte apoptosis, improved intestinal oxidative stress, promoted the activity and expression of protein kinase (BDL vs BDL + L. plantarum, 0.295 ± 0.007 vs 0.349 ± 0.003, P < 0.05; BDL + IBD vs BDL + IBD + L. plantarum, 0.407 ± 0.046 vs 0.465 ± 0.135, P < 0.05), and particularly enhanced the expression and phosphorylation of TJ proteins in the experimental obstructive jaundice (BDL vs BDL + L. plantarum, 0.266 ± 0.118 vs 0.326 ± 0.009, P < 0.05). The protective effect of L. plantarum was more prominent after internal biliary drainage ( BDL + IBD vs BDL + IBD + L. plantarum, 0.415 ± 0.105 vs 0.494 ± 0.145, P < 0.05). L. plantarum can decrease intestinal epithelial cell apoptosis, reduce oxidative stress, and prevent TJ disruption in biliary obstruction by activating the PKC pathway.

Transient, heat-induced thermal resistance in the small intestine of mouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hume, S.P.; Marigold, J.C.L.

Heat-induced thermal resistance has been investigated in mouse jejunum by assaying crypt survival 24 h after treatment. Hyperthermia was achieved by immersing an exteriorized loop of intestine in a bath of Krebs-Ringer solution. Two approaches have been used. In the first, thermal survival curves were obtained following single hyperthermal treatments at temperatures in the range 42 to 44/sup 0/C. Transient thermal resistance, inducted by a plateau in the crypt survival curve, developed during heating at temperatures around 42.5/sup 0/C after 60 to 80 min. In the second series of experiments, a priming heat treatment (40.0, 41.0, 41.5, or 42.0/sup 0/Cmore » for 60 min) was followed at varying intervals by a test treatment at 43.0/sup 0/C. A transient resistance to the second treatment was induced, the extent and time of development being dependent upon the priming treatment. Crypt survival curves for thermally resistant intestine showed an increase in thermal D/sub 0/ and a decrease in n compared with curves from previously unheated intestine.« less

Primary small intestine tumour as the cause of gastrointestinal tract occlusion.

PubMed

Fabiszewski, Arkadiusz; Brycht, Łukasz; Jackowski, Marek

2011-03-01

The following paper presents the case of a 40-year-old patient staying in our Clinic between 2 March 2010 and 12 March 2010 due to the symptoms of permeable occlusion of gastrointestinal tract. This is a patient with a several weeks' history of non-specific abdominal pain, vomiting and significant weight loss (ca 20 kg). Until recently he has not suffered from any serious illnesses. In the performed abdominal ultrasound, gastroscopy and colonoscopy no pathology was affirmed. CT scan with intravenous and oral contrast showed significantly widened intestinal loops with residual liquid matter in the stomach, duodenum and a part of the jejunum without any distinguishing pathological mass, and also single mesenteric lymph nodes and para-aortic nodes enlarged to the size of 12 mm. The patient was qualified for laparatomy. During the surgery, a 4-cm tumour of the jejunum, concentrically narrowing intestinal lumen was found. Segmental resection of the small intestine was performed with side to side anastomosis with the use of a linear stapler. Currently the general condition of the patient is good, without any ailments, and the patient is undergoing systemic treatment.

Disposition of lipid-based formulation in the intestinal tract affects the absorption of poorly water-soluble drugs.

PubMed

Iwanaga, Kazunori; Kushibiki, Toshihiro; Miyazaki, Makoto; Kakemi, Masawo

2006-03-01

Solvent Green 3 (SG), a model poorly water-soluble compound, was orally administered to rats with soybean oil emulsion or the Self-microemulsifying drug delivery system (SMEDDS) composed of Gelucire44/14. The bioavailability of SG after oral administration with SMEDDS was 1.7-fold higher than that with soybean oil emulsion. The intestinal absorption of lipid-based formulations themselves was evaluated by the in situ closed loop method. The effect of lipase and bile salt on their absorption was also evaluated. SMEDDS itself was rapidly absorbed in the intestine even in the absence of lipase and bile salt, and the absorption was increased by the addition of lipase and bile salt. On the other hand, no soybean oil emulsion was absorbed in the absence of lipase and bile salt. However, mixed micelle prepared from emulsion by incubating soybean oil emulsion with lipase and bile salt was rapidly absorbed through the intestine. Without lipase and bile salt, SG was not absorbed after administration with soybean oil emulsion. Therefore, we concluded that the degradation of soybean oil emulsion was needed for SG to be absorbed through the intestine. Furthermore, we investigated the intestinal absorption of SG after oral administration to rats whose chylomicron synthesis were inhibited by pretreatment with colchicine. Colchicine completely inhibited the intestinal absorption of SG after administration with each lipid-based formulation, suggesting that SG was absorbed from the intestine via a lymphatic route. Absorption of the dosage formulation should be paid attention when poorly water-soluble drugs are orally administered with lipid-based formulation.

Exploring new technologies to facilitate laparoscopic surgery: creating intestinal anastomoses without sutures or staples, using a radio-frequency-energy-driven bipolar fusion device.

PubMed

Smulders, J F; de Hingh, I H J T; Stavast, J; Jackimowicz, J J

2007-11-01

Intestinal anastomotic healing requires apposition of the collagen containing submucosal layers of the opposing intestinal walls, which is traditionally achieved by staples or sutures. Recently, a feedback-controlled bipolar sealing system (LigaSure) has been successfully introduced to seal and transect vessels. Since this technology depends on fusion of collagen fibres which are abundantly present in the intestinal wall, the possibility to create intestinal anastomoses using this technology was investigated in the present study. For this purpose a new-generation radiofrequency (RF) generator and a prototype of the Ligasure Anastomotic Device (LAD) have been developed. The generator incorporates a closed loop control system which monitors tissue fusion, compares it with a mathematical model of ideal fusion based on the density and compliance of intestinal tissue and adjusts energy output accordingly. In total 8 anastomoses were created in a porcine model (4 pigs, 2 anastomoses each) and healing was assessed by macroscopic and histological examination. All seals were macroscopic intact both immediate after creation and at sacrifice at the 7th postoperative day. Between operations, pigs appeared healthy and had normal intestinal passage. Histological examination of the anastomoses revealed undisturbed healing with granulation tissue, newly synthesised collagen in the submucosa and re-epithelialization at the borders of the seals. These results confirm the feasibility to create experimental intestinal anastomoses using LigaSure technology. This may be an important step towards the development of new laparoscopic equipment combining dissecting and reconstructive properties within one single instrument.

Intestinal alkaline phosphatase inhibits the proinflammatory nucleotide uridine diphosphate.

PubMed

Moss, Angela K; Hamarneh, Sulaiman R; Mohamed, Mussa M Rafat; Ramasamy, Sundaram; Yammine, Halim; Patel, Palak; Kaliannan, Kanakaraju; Alam, Sayeda N; Muhammad, Nur; Moaven, Omeed; Teshager, Abeba; Malo, Nondita S; Narisawa, Sonoko; Millán, José Luis; Warren, H Shaw; Hohmann, Elizabeth; Malo, Madhu S; Hodin, Richard A

2013-03-15

Uridine diphosphate (UDP) is a proinflammatory nucleotide implicated in inflammatory bowel disease. Intestinal alkaline phosphatase (IAP) is a gut mucosal defense factor capable of inhibiting intestinal inflammation. We used the malachite green assay to show that IAP dephosphorylates UDP. To study the anti-inflammatory effect of IAP, UDP or other proinflammatory ligands (LPS, flagellin, Pam3Cys, or TNF-α) in the presence or absence of IAP were applied to cell cultures, and IL-8 was measured. UDP caused dose-dependent increase in IL-8 release by immune cells and two gut epithelial cell lines, and IAP treatment abrogated IL-8 release. Costimulation with UDP and other inflammatory ligands resulted in a synergistic increase in IL-8 release, which was prevented by IAP treatment. In vivo, UDP in the presence or absence of IAP was instilled into a small intestinal loop model in wild-type and IAP-knockout mice. Luminal contents were applied to cell culture, and cytokine levels were measured in culture supernatant and intestinal tissue. UDP-treated luminal contents induced more inflammation on target cells, with a greater inflammatory response to contents from IAP-KO mice treated with UDP than from WT mice. Additionally, UDP treatment increased TNF-α levels in intestinal tissue of IAP-KO mice, and cotreatment with IAP reduced inflammation to control levels. Taken together, these studies show that IAP prevents inflammation caused by UDP alone and in combination with other ligands, and the anti-inflammatory effect of IAP against UDP persists in mouse small intestine. The benefits of IAP in intestinal disease may be partly due to inhibition of the proinflammatory activity of UDP.

Inhibitory effect and mechanism of acarbose combined with gymnemic acid on maltose absorption in rat intestine

PubMed Central

Luo, Hong; Wang, Le Feng; Imoto, Toshiaki; Hiji, Yasutake

2001-01-01

AIM: To compare the combinative and individual effect of acarbose and gymnemic acid (GA) on maltose absorption and hydrolysis in small intestine to determine whether nutrient control in diabetic care can be improved by combination of them. METHODS: The absorption and hydrolysis of maltose were studied by cyclic perfusion of intestinal loops in situ and motility of the intestine was recorded with the intestinal ring in vitro using Wistar rats. RESULTS: The total inhibitory rate of maltose absorption was improved by the combination of GA (0.1 g/L-1.0 g/L) and acarbose (0.1 mmol/L-2.0 mmol/L) throughout their effective duration (P < 0.05, U test of Mann-Whitney), although the improvement only could be seen at a low dosage during the first hour. With the combination, inhibitory duration of acarbose on maltose absorption was prolonged to 3 h and the inhibitory effect onset of GA was fastened to 15 min. GA suppressed the intestinal mobility with a good correlation (r = 0.98) to the inhibitory effect of GA on maltose absorption and the inhibitory effect of 2 mmol/L (high dose) acarbose on maltose hydrolysis was dual modulated by 1 g/L GA in vivo indicating that the combined effects involved the functional alteration of intestinal barriers. CONCLUSION: There are augmented effects of acarbose and GA, which involve pre-cellular and paracellular barriers. Diabetic care can be improved by employing the combination. PMID:11819725

Proteins with Novel Structure, Function and Dynamics

NASA Technical Reports Server (NTRS)

Pohorille, Andrew

2014-01-01

Recently, a small enzyme that ligates two RNA fragments with the rate of 10(exp 6) above background was evolved in vitro (Seelig and Szostak, Nature 448:828-831, 2007). This enzyme does not resemble any contemporary protein (Chao et al., Nature Chem. Biol. 9:81-83, 2013). It consists of a dynamic, catalytic loop, a small, rigid core containing two zinc ions coordinated by neighboring amino acids, and two highly flexible tails that might be unimportant for protein function. In contrast to other proteins, this enzyme does not contain ordered secondary structure elements, such as alpha-helix or beta-sheet. The loop is kept together by just two interactions of a charged residue and a histidine with a zinc ion, which they coordinate on the opposite side of the loop. Such structure appears to be very fragile. Surprisingly, computer simulations indicate otherwise. As the coordinating, charged residue is mutated to alanine, another, nearby charged residue takes its place, thus keeping the structure nearly intact. If this residue is also substituted by alanine a salt bridge involving two other, charged residues on the opposite sides of the loop keeps the loop in place. These adjustments are facilitated by high flexibility of the protein. Computational predictions have been confirmed experimentally, as both mutants retain full activity and overall structure. These results challenge our notions about what is required for protein activity and about the relationship between protein dynamics, stability and robustness. We hypothesize that small, highly dynamic proteins could be both active and fault tolerant in ways that many other proteins are not, i.e. they can adjust to retain their structure and activity even if subjected to mutations in structurally critical regions. This opens the doors for designing proteins with novel functions, structures and dynamics that have not been yet considered.

Replacing the Axial Ligand Tyrosine 75 or Its Hydrogen Bond Partner Histidine 83 Minimally Affects Hemin Acquisition by the Hemophore HasAp from Pseudomonas aeruginosa

PubMed Central

2015-01-01

Hemophores from Pseudomonas aeruginosa (HasAp), Serratia marcescens (HasAsm), and Yersinia pestis (HasAyp) bind hemin between two loops. One of the loops harbors conserved axial ligand Tyr75 (Y75 loop) in all three structures, whereas the second loop (H32 loop) contains axial ligand His32 in HasAp and HasAsm, but a noncoordinating Gln32 in HasAyp. Binding of hemin to the Y75 loop of HasAp or HasAsm causes a large rearrangement of the H32 loop that allows His32 coordination. The Q32 loop in apo-HasAyp is already in the closed conformation, such that binding of hemin to the conserved Y75 loop occurs with minimal structural rearrangement and without coordinative interaction with the Q32 loop. In this study, structural and spectroscopic investigations of the hemophore HasAp were conducted to probe (i) the role of the conserved Tyr75 loop in hemin binding and (ii) the proposed requirement of the His83–Tyr75 hydrogen bond to allow the coordination of hemin by Tyr75. High-resolution crystal structures of H83A holo-HasAp obtained at pH 6.5 (0.89 Å) and pH 5.4 (1.25 Å) show that Tyr75 remains coordinated to the heme iron, and that a water molecule can substitute for Nδ of His83 to interact with the Oη atom of Tyr75, likely stabilizing the Tyr75–Fe interaction. Nuclear magnetic resonance spectroscopy revealed that in apo-Y75A and apo-H83A HasAp, the Y75 loop is disordered, and that disorder propagates to nearby elements of secondary structure, suggesting that His83 Nδ–Tyr75 Oη interaction is important to the organization of the Y75 loop in apo-HasA. Kinetic analysis of hemin loading conducted via stopped-flow UV–vis and rapid-freeze-quench resonance Raman shows that both mutants load hemin with biphasic kinetic parameters that are not significantly dissimilar from those previously observed for wild-type HasAp. When the structural and kinetic data are taken together, a tentative model emerges, which suggests that HasA hemophores utilize hydrophobic, π–π stacking, and van der Waals interactions to load hemin efficiently, while axial ligation likely functions to slow hemin release, thus allowing the hemophore to meet the challenge of capturing hemin under inhospitable conditions and delivering it selectively to its cognate receptor. PMID:24625274

Efficacy, safety and mechanism of HP-β-CD-PEI polymers as absorption enhancers on the intestinal absorption of poorly absorbable drugs in rats.

PubMed

Zhang, Hailong; Huang, Xiaoyan; Zhang, Yongjing; Gao, Yang

2017-03-01

Oral bioavailability of some hydrophilic therapeutic macromolecules was very poor, thus leading to their limited application in clinic. To investigate the efficacy, safety and mechanism of HP-β-CD-PEI polymers on the intestinal absorption of some poorly absorbable drugs in rats. Effects of HP-β-CD-PEI polymers on the intestinal absorptions of drugs were investigated by an in situ closed loop method in rats. The safety of HP-β-CD-PEI polymer was evaluated by measurement of lactate dehydrogenase (LDH) activity and amount of protein released from rat intestinal perfusate. The absorption enhancing mechanisms were explored by the measurement of zeta potential, transepithelial electrical resistance (TEER) and in vitro transport of FD4 (a paracellular marker) across rat intestinal membranes, respectively. HP-β-CD-PEI polymers, especially HP-β-CD-PEI 1800 , demonstrated excellent absorption enhancing effects on drug absorption in a concentration-dependent manner and the enhancing effect was more efficient in the small intestine than that in the large intestine. Five percent (w/v) HP-β-CD-PEI 1800 obviously decreased the TEER, accompanied with increase in the intestinal transport of FD4, indicating that absorption enhancing actions of HP-β-CD-PEI polymers were possibly performed by loosening tight junctions of intestinal epithelium cells, thereby increasing drug permeation via a paracellular pathway. A good liner relationship between absorption enhancing effects of HP-β-CD-PEI polymers and their zeta potentials suggested the contribution of positive charge on the surface of these polymers to their absorption enhancing effects. HP-β-CD-PEI polymers might be potential and safe absorption enhancers for improving oral delivery of poorly absorbable macromolecules including peptides and proteins.

Dendrorchis pampae sp. n. (Digenea: Gorgoderidae) from Cynopoecilus melanotaenia (Cyprinodontiformes: Cynolebiidae) a killifish from southern Brazil, with an emended diagnosis of Dendrorchis.

PubMed

Monteiro, C M; Wendt, E W; Zebral, Y D

2018-04-15

A new species of Dendrorchis is described and compared with others in the genus. The parasites were found in the swim bladder of the annual killifish Cynopoecilus melanotaenia. Hosts were collected from a seasonal wetland in southern Brazil. The main characteristics of D. pampae are: genital pore in the intestinal bifurcation region elongate and lobed vitellaria uterine loops limited to the acetabular region and to the rear end of the body; and wide intestinal caeca. An emended diagnosis of the genus Dendrorchis includes the characteristics of the new species. This is the first record of an adult digenean in an annual killifish from South America.

Polyamidoamine dendrimers as novel potential absorption enhancers for improving the small intestinal absorption of poorly absorbable drugs in rats.

PubMed

Lin, Yulian; Fujimori, Takeo; Kawaguchi, Naoko; Tsujimoto, Yuiko; Nishimi, Mariko; Dong, Zhengqi; Katsumi, Hidemasa; Sakane, Toshiyasu; Yamamoto, Akira

2011-01-05

Effects of polyamidoamine (PAMAM) dendrimers on the intestinal absorption of poorly absorbable drugs were examined by an in situ closed loop method in rats. 5(6)-Carboxyfluorescein (CF), fluorescein isothiocyanate-dextrans (FDs) with various molecular weights, calcitonin and insulin were used as model drugs of poorly absorbable drugs. The absorption of CF, FD4 and calcitonin from the rat small intestine was significantly enhanced in the presence of PAMAM dendrimers. The absorption-enhancing effects of PAMAM dendrimers for improving the small intestinal absorption of CF were concentration and generation dependent and a maximal absorption-enhancing effect was observed in the presence of 0.5% (w/v) G2 PAMAM dendrimer. However, G2 PAMAM dendrimer had almost no absorption-enhancing effect on the small intestinal absorption of macromolecular drugs including FD10 and insulin. Overall, the absorption-enhancing effects of G2 PAMAM dendrimer in the small intestine decreased as the molecular weights of drug increased. However, G2 PAMAM dendrimer did not enhance the intestinal absorption of these drugs with different molecular weights in the large intestine. Furthermore, we evaluated the intestinal membrane damage with or without G2 PAMAM dendrimer. G2 PAMAM dendrimer (0.5% (w/v)) significantly increased the activities of lactate dehydrogenase (LDH) and the amounts of protein released from the intestinal membranes, but the activities and amounts of these toxic markers were less than those in the presence of 3% Triton X-100 used as a positive control. Moreover, G2 PAMAM dendrimer at concentrations of 0.05% (w/v) and 0.1% (w/v) did not increase the activities and amounts of these toxic markers. These findings suggested that PAMAM dendrimers at lower concentrations might be potential and safe absorption enhancers for improving absorption of poorly absorbable drugs from the small intestine. Copyright © 2010 Elsevier B.V. All rights reserved.

Bleeding from duodenal ulcer in a patient with bilio-pancreatic diversion.

PubMed

Garancini, Mattia; Luperto, Margherita; Delitala, Alberto; Maternini, Matteo; Uggeri, Franco

2011-12-01

Scopinaro's bilio-pancreatic diversion is considered as an acceptable malabsorptive surgical approach for the treatment of morbid obesity. We describe a case of acute recurrent gastro-intestinal bleeding in a patient with a previous Scopinaro's bilio-pancreatic diversion. At the first admission in our department, gastroscopy, colonoscopy, contrast-enhanced computerized tomography and angiography resulted negative for active bleeding. Hypovolemic shock indicated laparotomy and an intraoperative enteroscopy performed through a small enterotomy showed an ulcerative perforation sourced in an ischemic portion of a distended duodenal stump, with a bleeding branch of gastro-duodenal artery at the bottom. Hemorrhage was stopped with stitches. Two years later a new episode of duodenal bleeding associated with severe malnutrition occurred. A covered chronic ischemic perforation sustained by duodenal distension due to biliopancreatic limb sub-obstruction appeared to be the most probable etiology of the recurrent duodenal bleeding. The patient underwent again to laparotomy and adhesiolysis; hemorrhage was stopped by means of ligation of gastroduodenal artery and bilio-pancreatic diversion was converted into a standard Roux-en-Y gastroenterostomy with an entero-entero anastomosis 40 cm from the Treitz ligament in order to restore an anatomo-functional condition guaranteeing normal absorption and intestinal transit. After Scopinaro's bilio-pancreatic diversion duodenal bleeding can represent a rare serious presentation of biliopancreatic limb obstruction; because of the complex anatomical reconstruction performed during this intervention, the duodenum results unavailable during upper gastro-intestinal endoscopy, and if a duodenal bleeding is suspected laparotomy followed by enteroscopy represents an effective diagnostic approach.

Role of Gut Microbiota in Liver Disease.

PubMed

Brenner, David A; Paik, Yong-Han; Schnabl, Bernd

2015-01-01

Many lines of research have established a relationship between the gut microbiome and patients with liver disease. For example, patients with cirrhosis have increased bacteremia, increased blood levels of lipopolysaccharide, and increased intestinal permeability. Patients with cirrhosis have bacterial overgrowth in the small intestine. Selective intestinal decontamination with antibiotics is beneficial for patients with decompensated cirrhosis. In experimental models of chronic liver injury with fibrosis, several toll-like receptors (TLR) are required to make mice sensitive to liver fibrosis. The presumed ligand for the TLRs are bacterial products derived from the gut microbiome, and TLR knockout mice are resistant to liver inflammation and fibrosis. We and others have characterized the association between preclinical models of liver disease in mice with the microbial diversity in their gut microbiome. In each model, including intragastric alcohol, bile duct ligation, chronic carbon tetrachloride (CCl4), administration, and genetic obesity, there is a significant change in the gut microbiome from normal control mice. However, there is not a single clear bacterial strain or pattern that distinguish mice with liver injury from controlled mice. So how can the gut microbiota affect liver disease? We can identify at least 6 changes that would result in liver injury, inflammation, and/or fibrosis. These include: (1) changes in caloric yield of diet; (2) regulation of gut permeability to release bacterial products; (3) modulation of choline metabolism; (4) production of endogenous ethanol; (5) regulation of bile acid metabolism; and (6) regulation in lipid metabolism.

Caecal volvulus: a consequence of acute cholecystitis

PubMed Central

Anjum, Ghulam Ali; Jaberansari, Sarah; Habeeb, Kayode

2013-01-01

Caecal volvulus is an uncommon cause of closed loop intestinal obstruction which can lead to caecal gangrene and high mortality. Delay in diagnosis is one of the causes of this high mortality. Caecal volvulus is reported to be associated with previous abdominal surgery in most cases. We present the first reported case of caecal volvulus following/associated with acute cholecystitis. PMID:23749828

Endogenous molecular network reveals two mechanisms of heterogeneity within gastric cancer.

PubMed

Li, Site; Zhu, Xiaomei; Liu, Bingya; Wang, Gaowei; Ao, Ping

2015-05-30

Intratumor heterogeneity is a common phenomenon and impedes cancer therapy and research. Gastric cancer (GC) cells have generally been classified into two heterogeneous cellular phenotypes, the gastric and intestinal types, yet the mechanisms of maintaining two phenotypes and controlling phenotypic transition are largely unknown. A qualitative systematic framework, the endogenous molecular network hypothesis, has recently been proposed to understand cancer genesis and progression. Here, a minimal network corresponding to such framework was found for GC and was quantified via a stochastic nonlinear dynamical system. We then further extended the framework to address the important question of intratumor heterogeneity quantitatively. The working network characterized main known features of normal gastric epithelial and GC cell phenotypes. Our results demonstrated that four positive feedback loops in the network are critical for GC cell phenotypes. Moreover, two mechanisms that contribute to GC cell heterogeneity were identified: particular positive feedback loops are responsible for the maintenance of intestinal and gastric phenotypes; GC cell progression routes that were revealed by the dynamical behaviors of individual key components are heterogeneous. In this work, we constructed an endogenous molecular network of GC that can be expanded in the future and would broaden the known mechanisms of intratumor heterogeneity.

Endogenous molecular network reveals two mechanisms of heterogeneity within gastric cancer

PubMed Central

Li, Site; Zhu, Xiaomei; Liu, Bingya; Wang, Gaowei; Ao, Ping

2015-01-01

Intratumor heterogeneity is a common phenomenon and impedes cancer therapy and research. Gastric cancer (GC) cells have generally been classified into two heterogeneous cellular phenotypes, the gastric and intestinal types, yet the mechanisms of maintaining two phenotypes and controlling phenotypic transition are largely unknown. A qualitative systematic framework, the endogenous molecular network hypothesis, has recently been proposed to understand cancer genesis and progression. Here, a minimal network corresponding to such framework was found for GC and was quantified via a stochastic nonlinear dynamical system. We then further extended the framework to address the important question of intratumor heterogeneity quantitatively. The working network characterized main known features of normal gastric epithelial and GC cell phenotypes. Our results demonstrated that four positive feedback loops in the network are critical for GC cell phenotypes. Moreover, two mechanisms that contribute to GC cell heterogeneity were identified: particular positive feedback loops are responsible for the maintenance of intestinal and gastric phenotypes; GC cell progression routes that were revealed by the dynamical behaviors of individual key components are heterogeneous. In this work, we constructed an endogenous molecular network of GC that can be expanded in the future and would broaden the known mechanisms of intratumor heterogeneity. PMID:25962957

Inhibition of IKKß in enterocytes exacerbates sepsis-induced intestinal injury and worsens mortality

PubMed Central

Dominguez, Jessica A.; Samocha, Alexandr J.; Liang, Zhe; Burd, Eileen M.; Farris, Alton B.; Coopersmith, Craig M.

2013-01-01

Objective NF-kB is a critical regulator of cell survival genes and the host inflammatory response. The purpose of this study was to investigate the role of enterocyte-specific NF-kB in sepsis through selective ablation of IkB kinase (IKK)-ß. Design Prospective, randomized, controlled study. Setting Animal laboratories in university medical centers. Subjects and Interventions Mice lacking functional NF-kB in their intestinal epithelium (Vil-Cre/Ikkßf/Δ) and wild type (WT) mice were subjected to sham laparotomy or cecal ligation and puncture (CLP). Animals were sacrified at 24 hours or followed seven days for survival. Measurements and Main Results Septic WT mice had decreased villus length compared to sham mice while villus atrophy was further exacerbated in septic Vil-Cre/Ikkßf/Δ mice. Sepsis induced an increase in intestinal epithelial apoptosis compared to sham mice which was further exacerbated in Vil-Cre/Ikkßf/Δ mice. Sepsis induced intestinal hyperpermeability in WT mice compared to sham mice, which was further exacerbated in septic Vil-Cre/Ikkßf/Δ mice. This was associated with increased intestinal expression of claudin-2 in septic WT mice, which was further increased in septic Vil-Cre/Ikkßf/Δ mice. Both, pro-inflammatory and anti-inflammatory cytokines were increased in serum following CLP, and IL-10 and MCP-1 levels were higher in septic Vil-Cre/Ikkßf/Δ mice than septic WT mice. All septic mice were bacteremic, but no differences in bacterial load were identified between WT and Vil-Cre/Ikkßf/Δ mice. To determine the functional significance of these results, animals were followed for survival. Septic WT mice had lower mortality than septic Vil-Cre/Ikkßf/Δ mice (47% vs. 80%, p<0.05). Anti-TNF administration decreased intestinal apoptosis, permeability and mortality in WT septic mice and a similar improvement in intestinal integrity and survival were seen when anti-TNF was given to Vil-Cre/Ikkßf/Δ mice. Conclusions Enterocyte-specific NF-kB has a beneficial role in sepsis by partially preventing sepsis-induced increases in apoptosis and permeability, which are associated with worsening mortality. PMID:23939348

Site-Selective RNA Splicing Nanozyme: DNAzyme and RtcB Conjugates on a Gold Nanoparticle.

PubMed

Petree, Jessica R; Yehl, Kevin; Galior, Kornelia; Glazier, Roxanne; Deal, Brendan; Salaita, Khalid

2018-01-19

Modifying RNA through either splicing or editing is a fundamental biological process for creating protein diversity from the same genetic code. Developing novel chemical biology tools for RNA editing has potential to transiently edit genes and to provide a better understanding of RNA biochemistry. Current techniques used to modify RNA include the use of ribozymes, adenosine deaminase, and tRNA endonucleases. Herein, we report a nanozyme that is capable of splicing virtually any RNA stem-loop. This nanozyme is comprised of a gold nanoparticle functionalized with three enzymes: two catalytic DNA strands with ribonuclease function and an RNA ligase. The nanozyme cleaves and then ligates RNA targets, performing a splicing reaction that is akin to the function of the spliceosome. Our results show that the three-enzyme reaction can remove a 19 nt segment from a 67 nt RNA loop with up to 66% efficiency. The complete nanozyme can perform the same splice reaction at 10% efficiency. These splicing nanozymes represent a new promising approach for gene manipulation that has potential for applications in living cells.

Enzyme-adenylate structure of a bacterial ATP-dependent DNA ligase with a minimized DNA-binding surface.

PubMed

Williamson, Adele; Rothweiler, Ulli; Leiros, Hanna Kirsti Schrøder

2014-11-01

DNA ligases are a structurally diverse class of enzymes which share a common catalytic core and seal breaks in the phosphodiester backbone of double-stranded DNA via an adenylated intermediate. Here, the structure and activity of a recombinantly produced ATP-dependent DNA ligase from the bacterium Psychromonas sp. strain SP041 is described. This minimal-type ligase, like its close homologues, is able to ligate singly nicked double-stranded DNA with high efficiency and to join cohesive-ended and blunt-ended substrates to a more limited extent. The 1.65 Å resolution crystal structure of the enzyme-adenylate complex reveals no unstructured loops or segments, and suggests that this enzyme binds the DNA without requiring full encirclement of the DNA duplex. This is in contrast to previously characterized minimal DNA ligases from viruses, which use flexible loop regions for DNA interaction. The Psychromonas sp. enzyme is the first structure available for the minimal type of bacterial DNA ligases and is the smallest DNA ligase to be crystallized to date.

Late effects of intraoperative radiation therapy on retroperitoneal tissues, intestine, and bile duct in a large animal model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sindelar, W.F.; Tepper, J.E.; Kinslla, T.J.

1994-07-01

The late histopathological effects of intraoperative radiotherapy (IORT) on retroperitoneal tissues, intestine, and bile duct were investigated in dogs. Fourteen adult foxhounds were subjected to laparotomy and varying doses (0-45 Gy) of IORT (11 MeV electrons) delivered to retroperitoneal tissues including the great vessels and ureters, to a loop of defunctionalized small bowel, or to the extrahepatic bile duct. One control animal received an aortic transection and reanastomosis at the time of laparotomy; another control received laparotomy alone. This paper describes the late effects of single-fraction IORT occurring 3-5 years following treatment. Dogs receiving IORT to the retroperitoneum through amore » 4 X 15 cm portal showed few gross or histologic abnormalities at 20 Gy. At doses ranging from 30-45 Gy, radiation changes in normal tissues were consistently observed. Retroperitoneal fibrosis with encasement of the ureters and great vessels developed at doses {ge}30 Gy. Radiation changes were present in the aorta and vena cava at doses {ge}40 Gy. A 30 Gy dog developed an in-field malignant osteosarcoma at 3 years which invaded the vertebral column and compressed the spinal cord. A 40 Gy animal developed obstruction of the right ureter with fatal septic hydronephrosis at 4 years. Animals receiving IORT through a 5 cm IORT portal to an upper abdominal field which included a defunctionalized loop of small bowel, showed few gross or histologic abnormalities at a dose of 20 Gy. At 30 Gy, hyaline degeneration of the intestinal muscularis layer of the bowel occurred. At a dose of 45 Gy, internal intestinal fistulae developed. One 30 Gy animal developed right ureteral obstruction and hydronephrosis at 5 years. A dog receiving 30 Gy IORT through a 5 cm portal to the extrahepatic bile duct showed diffuse fibrosis through the gastroduodenal ligament. These canine studies contribute to the area of late tissue tolerance to IORT. 7 refs., 3 figs., 5 tabs.« less

Dipeptide transport and hydrolysis in isolated loops of rat small intestine: effects of stereospecificity.

PubMed Central

Lister, N; Sykes, A P; Bailey, P D; Boyd, C A; Bronk, J R

1995-01-01

1. Isolated jejunal loops of rat small intestine were perfused by a single pass of bicarbonate Krebs-Ringer solution containing either D- or L-phenylalanine or one of eight dipeptides formed from D- or L-alanine plus D- or L-phenylalanine. 2. At 0.5 mM L-phenylalanyl-L-alanine increased serosal phenylalanine appearance to forty times the control rate giving a value similar to that found with 0.5 mM free L-phenylalanine. No serosal dipeptide could be detected. 3. Perfusions with the two mixed dipeptides with N-terminal D-amino acids (D-alanyl-L-phenylalanine and D-phenylalanyl-L-alanine) gave rise to the appearance of intact dipeptides in the serosal secretions although there were substantial differences in their rates of absorption and subsequent hydrolysis. 4. L-Alanyl-D-phenylalanine was absorbed from the lumen three to five times as fast as L-phenylalanyl-D-alanine. At 1 mM L-alanyl-D-phenylalanine transferred D-phenylalanine across the epithelial layer at more than seven times the rate found with the same concentration of the free D-amino acid. 5. Perfusions with D-alanyl-D-phenylalanine or D-phenylalanyl-D-alanine showed that these two dipeptides are poor substrates for both transport and hydrolysis by the rat small intestine. 6. Analysis of mucosal tissue extracts after perfusion with the two mixed dipeptides with N-terminal D-amino acids revealed that both dipeptides were accumulated within the mucosa and suggested that exit across the basolateral membrane was rate limiting for transepithelial dipeptide transport. Images Figure 5 PMID:7602518

YghJ, the secreted metalloprotease of pathogenic E. coli induces hemorrhagic fluid accumulation in mouse ileal loop.

PubMed

Tapader, Rima; Bose, Dipro; Pal, Amit

2017-04-01

YghJ, also known as SslE (Secreted and surface associated lipoprotein) is a cell surface associated and secreted lipoprotein harbouring M60 metalloprotease domain. Though the gene is known to be conserved among both pathogenic and commensal Escherichia coli isolates, the expression and secretion of YghJ was found to be higher among diverse E. coli pathotypes. YghJ, secreted from intestinal pathogens such as enterotoxigenic E. coli (ETEC) and enteropathogenic E. coli (EPEC) has been demonstrated to possess mucinase activity and hence facilitates colonization of these enteric pathogens to intestinal epithelial cells. Importantly, YghJ is also reported to be secreted from extraintestinal pathogenic E. coli isolates. In our previous study we have shown that YghJ, purified from a neonatal septicemic E. coli isolate could trigger induction of various proinflammatory cytokines in vitro. This led us to investigate the role of YghJ in causing in vivo tissue hemorrhage. In the present study, we validate the earlier in vitro finding and have showed that YghJ can cause extensive tissue damage in mouse ileum and is also able to induce significant fluid accumulation in a dose dependent manner in a mouse ileal loop (MIL) assay. Hence, our present study not only confirms the pathogenic potential of YghJ in sepsis pathophysiology but also indicates the enterotoxic ability of YghJ which makes it an important virulence determinant of intestinal pathogenic E. coli. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of N(G)-nitro-L-arginine methyl ester on intestinal permeability following intestinal ischemia-reperfusion injury in a rat model.

PubMed

Luo, C C; Chen, H M; Chiu, C H; Lin, J N; Chen, J C

2001-07-01

Subclinical intestinal ischemia-reperfusion injury (IRI) causes an increase in mucosal permeability and may represent an early event in the pathogenesis of necrotizing enterocolitis in premature infants. Previous studies suggested that continuous, endogenous formation of nitric oxide (NO) maintains the mucosal integrity of the intestine, thus protecting the gut from injuries from blood-borne toxins and tissue-destructive mediators. This study was undertaken to assess whether the inhibition of NO production causes an increase in intestinal permeability in rats following IRI. Sprague-Dawley rats weighing 200-300 g were divided into 4 groups: (1) untreated group (normal control); (2) ischemia-reperfusion group; (3) early N(G)-nitro-L-arginine methyl ester (L-NAME), a specific inhibitor of NO production, treatment group, and (4) late L-NAME treatment group. Transient IRI was induced by 30-min occlusion, followed by reperfusion of the isolated ileal loop. The L-NAME was administered 15 min before and after mesenteric ischemia as a 25-mg/kg bolus. Fluorescein isothiocyanate-dextran (FITC-D) was used to quantitatively assess the alteration in mucosal permeability of the intestine. There was no significant increase in the portal vein FITC-D level among normal controls, ischemia-reperfusion group and late L-NAME-treated group, but there was an approximately 6-fold increase in the early L-NAME treatment group. The pathological features of the intestine following IRI include denudation of the villus epithelium and reduction of villus height, associated with marked inflammatory cell infiltration over the lamina propria. These results suggest that endogenous NO may play a role in the protecting intestinal integrity after IRI. Copyright 2001 S. Karger AG, Basel

Intestinal alkaline phosphatase inhibits the proinflammatory nucleotide uridine diphosphate

PubMed Central

Hamarneh, Sulaiman R.; Mohamed, Mussa M. Rafat; Ramasamy, Sundaram; Yammine, Halim; Patel, Palak; Kaliannan, Kanakaraju; Alam, Sayeda N.; Muhammad, Nur; Moaven, Omeed; Teshager, Abeba; Malo, Nondita S.; Narisawa, Sonoko; Millán, José Luis; Warren, H. Shaw; Hohmann, Elizabeth; Malo, Madhu S.; Hodin, Richard A.

2013-01-01

Uridine diphosphate (UDP) is a proinflammatory nucleotide implicated in inflammatory bowel disease. Intestinal alkaline phosphatase (IAP) is a gut mucosal defense factor capable of inhibiting intestinal inflammation. We used the malachite green assay to show that IAP dephosphorylates UDP. To study the anti-inflammatory effect of IAP, UDP or other proinflammatory ligands (LPS, flagellin, Pam3Cys, or TNF-α) in the presence or absence of IAP were applied to cell cultures, and IL-8 was measured. UDP caused dose-dependent increase in IL-8 release by immune cells and two gut epithelial cell lines, and IAP treatment abrogated IL-8 release. Costimulation with UDP and other inflammatory ligands resulted in a synergistic increase in IL-8 release, which was prevented by IAP treatment. In vivo, UDP in the presence or absence of IAP was instilled into a small intestinal loop model in wild-type and IAP-knockout mice. Luminal contents were applied to cell culture, and cytokine levels were measured in culture supernatant and intestinal tissue. UDP-treated luminal contents induced more inflammation on target cells, with a greater inflammatory response to contents from IAP-KO mice treated with UDP than from WT mice. Additionally, UDP treatment increased TNF-α levels in intestinal tissue of IAP-KO mice, and cotreatment with IAP reduced inflammation to control levels. Taken together, these studies show that IAP prevents inflammation caused by UDP alone and in combination with other ligands, and the anti-inflammatory effect of IAP against UDP persists in mouse small intestine. The benefits of IAP in intestinal disease may be partly due to inhibition of the proinflammatory activity of UDP. PMID:23306083

Silver ions-mediated conformational switch: facile design of structure-controllable nucleic acid probes.

PubMed

Wang, Yongxiang; Li, Jishan; Wang, Hao; Jin, Jianyu; Liu, Jinhua; Wang, Kemin; Tan, Weihong; Yang, Ronghua

2010-08-01

Conformationally constraint nucleic acid probes were usually designed by forming an intramolecular duplex based on Watson-Crick hydrogen bonds. The disadvantages of these approaches are the inflexibility and instability in complex environment of the Watson-Crick-based duplex. We report that this hydrogen bonding pattern can be replaced by metal-ligation between specific metal ions and the natural bases. To demonstrate the feasibility of this principle, two linear oligonucleotides and silver ions were examined as models for DNA hybridization assay and adenosine triphosphate detection. The both nucleic acids contain target binding sequences in the middle and cytosine (C)-rich sequences at the lateral portions. The strong interaction between Ag(+) ions and cytosines forms stable C-Ag(+)-C structures, which promises the oligonucleotides to form conformationally constraint formations. In the presence of its target, interaction between the loop sequences and the target unfolds the C-Ag(+)-C structures, and the corresponding probes unfolding can be detected by a change in their fluorescence emission. We discuss the thermodynamic and kinetic opportunities that are provided by using Ag(+) ion complexes instead of traditional Watson-Crick-based duplex. In particular, the intrinsic feature of the metal-ligation motif facilitates the design of functional nucleic acids probes by independently varying the concentration of Ag(+) ions in the medium.

[Study of the antireflux action of the Roux-en-Y jejunal loop in reconstruction after gastrectomy and nutritional status in the follow-up].

PubMed

Rea, Teresa; Bartolacci, Mauro; Leombruni, Edoardo; Brizzi, Felice; Picardi, Nicola

2005-01-01

The Roux-en-Y recostruction after total or subtotal gastrectomy for gastric cancer is frequently performed to prevent esophageal alkaline reflux. Also after total gastrectomy and end-to-side gastrojejunal anastomosis, as usual in former experience, the alkaline reflux can be efficaciously treated by conversion in an esophago-jejunal Roux-en-Y procedure. The main factor preventing reflux is the length of jejunal loop, at least of 35-40 cm. The recostruction with a Roux-en-Y jejunal loop offers the advantage to meet together two primary requirements: the restoration of digestive travel from esophagus to intestine, and the prevention of on alcaline reflux esophagitis, both with relevant simplicity and without a time-consuming surgical technique. Also as a consequence the postoperative morbidity is decreased. The obvious suitable requirement is a sufficient lenght of the jejunal loop for a reservoir of the ingested food and to oppose the antiperistaltic jejunal movements thanks to the effects of the new activated jejunal pace-maker.

Activation of AMPK Inhibits Cholera Toxin Stimulated Chloride Secretion in Human and Murine Intestine

PubMed Central

Hoekstra, Nadia; Collins, Danielle; Collaco, Anne; Baird, Alan W.; Winter, Desmond C.; Ameen, Nadia; Geibel, John P.; Kopic, Sascha

2013-01-01

Increased intestinal chloride secretion through chloride channels, such as the cystic fibrosis transmembrane conductance regulator (CFTR), is one of the major molecular mechanisms underlying enterotoxigenic diarrhea. It has been demonstrated in the past that the intracellular energy sensing kinase, the AMP-activated protein kinase (AMPK), can inhibit CFTR opening. We hypothesized that pharmacological activation of AMPK can abrogate the increased chloride flux through CFTR occurring during cholera toxin (CTX) mediated diarrhea. Chloride efflux was measured in isolated rat colonic crypts using real-time fluorescence imaging. AICAR and metformin were used to activate AMPK in the presence of the secretagogues CTX or forskolin (FSK). In order to substantiate our findings on the whole tissue level, short-circuit current (SCC) was monitored in human and murine colonic mucosa using Ussing chambers. Furthermore, fluid accumulation was measured in excised intestinal loops. CTX and forskolin (FSK) significantly increased chloride efflux in isolated colonic crypts. The increase in chloride efflux could be offset by using the AMPK activators AICAR and metformin. In human and mouse mucosal sheets, CTX and FSK increased SCC. AICAR and metformin inhibited the secretagogue induced rise in SCC, thereby confirming the findings made in isolated crypts. Moreover, AICAR decreased CTX stimulated fluid accumulation in excised intestinal segments. The present study suggests that pharmacological activation of AMPK effectively reduces CTX mediated increases in intestinal chloride secretion, which is a key factor for intestinal water accumulation. AMPK activators may therefore represent a supplemental treatment strategy for acute diarrheal illness. PMID:23935921

Changes in intestinal absorption of nutrients and brush border glycoproteins after total parenteral nutrition in rats.

PubMed Central

Miura, S; Tanaka, S; Yoshioka, M; Serizawa, H; Tashiro, H; Shiozaki, H; Imaeda, H; Tsuchiya, M

1992-01-01

The effect of total parenteral nutrition on nutrients absorption and glycoprotein changes of brush border membrane was examined in rat small intestine. In total parenteral nutrition rats, a marked decrease in activity of brush border enzymes was observed mainly in the proximal and middle segments of the intestine. Galactose perfusion of jejunal segment showed that hexose absorption was significantly inhibited, while intestinal absorption of glycine or dipeptide, glycylglycine was not significantly affected by total parenteral nutrition treatment. When brush border membrane glycoprotein profile was examined by [3H]-glucosamine or [3H]-fucose incorporation into jejunal loops, significant changes were observed in the glycoprotein pattern of brush border membrane especially in the high molecular weight range over 120 kDa after total parenteral nutrition treatment, suggesting strong dependency of glycoprotein synthesis on luminal substances. Molecular weight of sucrase isomaltase in brush border membrane detected by specific antibody showed no significant difference, however, in total parenteral nutrition and control rats. Also, molecular weight of specific sodium glucose cotransporter of intestinal brush border membrane detected by selective photoaffinity labelling was not altered in total parenteral nutrition rats. It may be that prolonged absence of oral food intake may produce significant biochemical changes in brush border membrane glycoprotein and absorptive capacity of small intestine, but these changes were not observed in all brush border membrane glycoproteins. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:1582592

Successful treatment of recurrent cholangitis by constructing a hepaticojejunostomy with long Roux-en-Y limb in a long-term surviving patient after a Whipple procedure for pancreatic adenocarcinoma.

PubMed

Tsalis, Konstantinos; Antoniou, Nikolaos; Koukouritaki, Zambia; Patridas, Dimitrios; Sakkas, Leonidas; Kyziridis, Dimitrios; Lazaridis, Charalampos

2014-08-20

Female, 74. Recurrent cholangitis. -. -. -. Gastroenterology and Hepatology. Unusual clinical course. Cholangitis may result from biliary obstruction (e.g., biliary or anastomotic stenosis, or foreign bodies) or occur in the presence of normal biliary drainage. Although reflux of intestinal contents into the biliary tree after hepaticojejunostomy appears to be a rare complication, it is important to emphasize that there are few available surgical therapeutic techniques. A 74-year-old woman presented to our hospital after 17 years of episodes of cholangitis. The patient had undergone a pancreatoduodenectomy (Whipple procedure) 18 years earlier due to pancreatic adenocarcinoma. The reconstruction was achieved through the sequential placement of pancreatic, biliary, and retrocolic gastric anastomosis into the same jejunal loop. The postoperative course was uneventful and the patient received adjuvant chemotherapy. Approximately 6 months after the initial operation, the patient started having episodes of cholangitis. Over the next 17 years she experienced several febrile episodes presumed to be secondary to cholangitis. A computing tomography (CT) scan of the abdomen revealed intrahepatic bile ducts partially filled with orally administered contrast material (Gastrografin). Magnetic resonance cholangiopancreatography (MRCP) showed dilatation of the left intrahepatic bile ducts. A percutaneous transhepatic cholangiography showed that the bilioenteric anastomosis was normal, without stenosis. Based on these findings, a diagnosis of a short loop between the hepaticojejunostomy and the gastrojejunostomy permitting the reflux of intestinal juice into the biliary tree was made. During the re-operation, a new hepaticojejunal anastomosis in a 100-cm long Roux-en-Y loop was performed to prevent the reflux of the intestinal fluid into the biliary tree. The patient was discharged on postoperative day 10. One year after the second procedure, the patient enjoys good health and has been free of fever and abdominal pain and has not received any antibiotic therapy. Lengthening the efferent Roux-en-Y limb should be considered as a therapeutic option when treating a patient with recurrent episodes of cholangitis after hepaticojejunostomy.

In vitro smooth muscle contractility before and after relief of experimental obstruction in the rat: application to the surgical management of ileal dilatation.

PubMed

Haraux, Elodie; Canarelli, Jean-Pierre; Khorsi, Hafida; Delanaud, Stéphane; Bach, Véronique; Gay-Quéheillard, Jérome

2014-03-01

Bowel dilatation occurs proximal to an obstruction and predisposes to intestinal dysmotility. The present study sought to determine whether or not changes in smooth muscle contractility and the thickness of the proximal, dilated bowel wall can be reversed following relief of the obstruction. Three groups of seven male Wistar rats were studied. In 8-week-old animals in a control group and a sham-operated group, a small segment of bowel (designated as R1 for controls and R2 for shams) was resected 5.0 cm from the cecum. In the third (operated) group, a narrow, isoperistaltic intestinal loop was created proximal to an end-to-end anastomosis of the ileum in 4-week-old animals. When these animals were 6 weeks old, the loop was re-anastomosed to the distal small bowel (after resection of the loop's distal portion, referred to as R3). Two weeks later, a small segment of bowel was resected proximal to the anastomosis (R4). We evaluated the thickness of the smooth muscle layers and the in vitro contractile responses of circular smooth muscle ileal strips (R1-R4) to electrical stimulation and pharmacological stimulation (with KCl, acetylcholine (ACh), substance P, N(G)-nitro-l-arginine methyl ester (L-NAME) and histamine). The amplitudes of contraction in response to electrical and Ach-mediated stimulation were higher for R3 than for R4 (P<0.001), R1 and R2 (both P<0.05). Compared with R1 and R2, the smooth muscle layer was three times as thick in R3 (P<0.001) and 2.5 times as thick in R4 (P<0.01). Our study provides evidence of the possible recovery of intestinal motility (in response to neurotransmitters involved in gut function) after the relief of an obstruction. If ileal motility can conceivably return to normal values, conservative surgical procedures in pediatric patients should be preferred (in order to leave a sufficient length of bowel and avoid short bowel syndrome). © 2013 Elsevier Inc. All rights reserved.

[[Estimation of bilio-oigestive and interintestinal anastomoses, formed in accordance to method of a high-frequency electric welding of tissues, in experiment].

PubMed

Hutsuliak, A I

2016-08-01

In the experiment on 50 rabbits cholecysto-entero and entero-entero anastomoses were formed on intestinal Roux loop. In 35 animals (the main group) a single layer evert- ing anastomoses by using high frequence (HF) electric welding method were formed, in 15 (the comparison group) single row suture anastomoses has been done. The anas- tomosis sufficiency were performed by using hydropressure, pneumopressure meth- ods and breakload test. It was established that all anastomoses formed by HF-electric welding method were passable and hermetic, also had strong sufficiency. Strength of weld joint in the postoperative period increased in a linear progression and after 3 weeks almost reached strength intact intestine (240-250 mm Hg).

Scallop DMT functions as a Ca2+ transporter.

PubMed

Toyohara, Haruhiko; Yamamoto, Sayuri; Hosoi, Masatomi; Takagi, Masaya; Hayashi, Isao; Nakao, Kenji; Kaneko, Shuji

2005-05-09

We identified a DMT (divalent metal transporter) homologous protein that functions as a Ca(2+) transporter. Scallop DMT cDNA encodes a 539-amino-acid protein with 12 putative membrane-spanning domains and has a consensus transport motif in the fourth extracellular loop. Since its mRNA is significantly expressed in the gill and intestine, it is assumed that scallop DMT transports Ca(2+) from seawater by the gill and from food by the intestine. Scallop DMT lacks the iron-responsive element commonly found in iron-regulatory proteins, suggesting that it is free of the post-transcriptional regulation from intracellular Fe(2+) concentration. Scallop DMT distinctly functions as a Ca(2+) transporter unlike other DMTs, however, it also transports Fe(2+) and Cd(2+) similar to them.

[Prevention of side effects and complications after operation for partial ileal bypass].

PubMed

Mirchuk, K K; Sedletskiĭ, Iu I

2014-01-01

Side effects and complications of the application of partial ileal bypass used for dislipidemia were analyzed in 162 patients with atherosclerosis. It was shown, that the partial ileal bypass operation could lead to the development of series of undesirable side effects such as diarrhea, hypovitaminosis B12, off-state intestine enteritis. The application of modification of partial ileal bypass such as formation of ileo-ileoanastomosis 5-6 cm long near ileocecal valve with the maintenance of its functions disposed the diarrhea and minimized the risk of the development of hypovitaminosis B12 after operation. It is possible to prevent the development of enteritis of off-state loop of the small intestine by using microanastomosis between off-state and functioning iliac intestine. The partial ileal bypass operation didn't influence on body weight, wouldn't increase the risk of stone formation in the gallbladder and kidneys. The risk of the development of hypovitaminosis B12 is minimal after operation.

Clinics in diagnostic imaging (171). Caecal volvulus with underlying intestinal malrotation.

PubMed

Ooi, Su Kai Gideon; Tan, Tien Jin; Ngu, James Chi Yong

2016-11-01

A 46-year-old Chinese woman with a history of cholecystectomy and appendicectomy presented to the emergency department with symptoms of intestinal obstruction. Physical examination revealed central abdominal tenderness but no clinical features of peritonism. Plain radiography of the abdomen revealed a grossly distended large bowel loop with the long axis extending from the right lower abdomen toward the epigastrium, and an intraluminal air-fluid level. These findings were suspicious for an acute caecal volvulus, which was confirmed on subsequent contrast-enhanced computed tomography (CT) of the abdomen and pelvis. CT demonstrated an abnormal positional relationship between the superior mesenteric vein and artery, indicative of an underlying intestinal malrotation. This case highlights the utility of preoperative imaging in establishing the diagnosis of an uncommon cause of bowel obstruction. It also shows the importance of recognising the characteristic imaging features early, so as to ensure appropriate and expedient management, thus reducing patient morbidity arising from complications. Copyright: © Singapore Medical Association.

Clinical, ultrasonographic, and pathologic findings in 70 camels (Camelus dromedarius) with Johne’s disease

PubMed Central

Tharwat, Mohamed; Al-Sobayil, Fahd; Ali, Ahmed; Hashad, Mahmoud; Buczinski, Sébastien

2012-01-01

This study evaluated the use of ultrasonography for the diagnosis of Johne’s disease in camels (Camelus dromedarius). Seventy camels with confirmed Johne’s disease were examined by ultrasonography and subsequent necropsy; 15 healthy camels were included as controls. The most outstanding findings were visible enlargement of the mesenteric lymph nodes in 52 (74%) camels. Lesions had either echogenic (26%; n = 18) or anechoic (69%; n = 48) capsule and the contents were either anechoic (21%; n = 15), echogenic (27%; n = 19), or heterogeneous (46%; n = 32). Clumps of echogenic tissue interspersed with fluid pockets were imaged between the intestinal loops in 9 (13%) camels. There was mild, moderate, or severe thickening and corrugation of the intestinal wall, excessive anechoic fluid in the abdominal cavity in 18 (26%) camels, increased hepatic brightness in 30 (43%) camels, and pericardial and pleural effusions in 22 (31%) camels. Sensitivity values for detecting intestinal lesions and enlarged mesenteric lymph nodes were 95% and 84%, respectively. PMID:23115369

Clinical, ultrasonographic, and pathologic findings in 70 camels (Camelus dromedarius) with Johne's disease.

PubMed

Tharwat, Mohamed; Al-Sobayil, Fahd; Ali, Ahmed; Hashad, Mahmoud; Buczinski, Sébastien

2012-05-01

This study evaluated the use of ultrasonography for the diagnosis of Johne's disease in camels (Camelus dromedarius). Seventy camels with confirmed Johne's disease were examined by ultrasonography and subsequent necropsy; 15 healthy camels were included as controls. The most outstanding findings were visible enlargement of the mesenteric lymph nodes in 52 (74%) camels. Lesions had either echogenic (26%; n = 18) or anechoic (69%; n = 48) capsule and the contents were either anechoic (21%; n = 15), echogenic (27%; n = 19), or heterogeneous (46%; n = 32). Clumps of echogenic tissue interspersed with fluid pockets were imaged between the intestinal loops in 9 (13%) camels. There was mild, moderate, or severe thickening and corrugation of the intestinal wall, excessive anechoic fluid in the abdominal cavity in 18 (26%) camels, increased hepatic brightness in 30 (43%) camels, and pericardial and pleural effusions in 22 (31%) camels. Sensitivity values for detecting intestinal lesions and enlarged mesenteric lymph nodes were 95% and 84%, respectively.

Organo-axial volvulus of the small intestine: radiological case report and consideration for its mechanism.

PubMed

Ishiguro, Toshitaka; Hiyama, Takashi; Nasu, Katsuhiro; Akashi, Yoshimasa; Minami, Manabu

2017-07-01

Gastrointestinal volvulus is mainly classified into two subtypes, mesentero-axial volvulus and organo-axial volvulus. The detailed imaging findings of organo-axial volvulus of the small intestine have never been reported as far as we know. In this article, we report a case of organo-axial volvulus of the small intestine, focusing on the computed tomography (CT) findings. An 80-year-old man was radiologically diagnosed as having organo-axial volvulus of the terminal ileum and it was confirmed by open surgery without adhesion or any other anatomical abnormalities. CT showed two specific findings, split-bowel sign and rotating-C sign, which we think reflect pathophysiologic features of organo-axial volvulus. We think the pathogenic mechanism of organo-axial volvulus can be explained by the convergence of the reversed-rotational twist following the formation of a twisted but non-obstructive circular loop, even if there is no adhesion. Radiologists should be aware that organo-axial volvulus can occur even in the small intestine, and in the case of small bowel obstruction with single transition point, the two pathophysiologic signs mentioned above must be looked for to diagnose the possibility of organo-axial volvulus.

Effects of a single dose of menadione on the intestinal calcium absorption and associated variables.

PubMed

Marchionatti, Ana M; Díaz de Barboza, Gabriela E; Centeno, Viviana A; Alisio, Arturo E; Tolosa de Talamoni, Nori G

2003-08-01

The effect of a single large dose of menadione on intestinal calcium absorption and associated variables was investigated in chicks fed a normal diet. The data show that 2.5 micro mol of menadione/kg of b.w. causes inhibition of calcium transfer from lumen-to-blood within 30 min. This effect seems to be related to oxidative stress provoked by menadione as judged by glutathione depletion and an increment in the total carbonyl group content produced at the same time. Two enzymes presumably involved in calcium transcellular movement, such as alkaline phosphatase, located in the brush border membrane, and Ca(2+)- pump ATPase, which sits in the basolateral membrane, were also inhibited. The enzyme inhibition could be due to alterations caused by the appearance of free hydroxyl groups, which are triggered by glutathione depletion. Addition of glutathione monoester to the duodenal loop caused reversion of the menadione effect on both intestinal calcium absorption and alkaline phosphatase activity. In conclusion, menadione shifts the balance of oxidative and reductive processes in the enterocyte towards oxidation causing deleterious effects on intestinal Ca(2+) absorption and associated variables, which could be prevented by administration of oral glutathione monoester.

Spontaneous remission of obstructive jaundice in rats: Selection of experimental models

PubMed Central

Lv, Yunfu; Yue, Jie; Gong, Xiaoguang; Han, Xiaoyu; Wu, Hongfei; Deng, Jie; Li, Yejuan

2018-01-01

The aim of the present study was to evaluate the prevalence and causes of spontaneous remission of obstructive jaundice in rats. Healthy male and female Wistar rats (180–220 g) were randomly assigned to receive common bile duct ligation (CBDL) and transection (group A), CBDL only (group B), or CBD dissection without ligation or transection (control group C; n=36 in each group). There was a difference in eye and skin jaundice prevalence between groups A and B from 14 days after surgery. The level of total bilirubin (TB) did not continue to increase in group A and began to decrease in the majority of rats in group B (P<0.05 vs. group B). At day 21 after surgery, the TB level returned to normal in group B and no significant difference was observed compared with group C. At day 21 after surgery, significant dilatation of bile ducts above the ligature was observed in group A following cholangiography with 38% meglumine diatrizoate and this contrast agent did not spread to other sites. Slight dilatation of the proximal bile ducts was observed in group B and the contrast agent entered the intestinal lumen through the omental ducts adhering to the porta hepatis. After 14 days of surgery, there were 36 rats in group A and B, and 17 rats exhibited spontaneous regression of jaundice. Overall, 47.2% (17/36) of rats experienced spontaneous remission of obstructive jaundice, 82.4% (14/17) of which underwent ligation only. The spontaneous remission of jaundice may have been caused by shunting through very small bile ducts or omental ducts adhering to the porta hepatis. If a model of biliary obstruction is to be established in future research, a model of CBDL and transection is preferable. In this case, jaundice reduction surgery should be performed 14 days after establishment of the model. PMID:29904412

Comparison of Hi-C results using in-solution versus in-nucleus ligation.

PubMed

Nagano, Takashi; Várnai, Csilla; Schoenfelder, Stefan; Javierre, Biola-Maria; Wingett, Steven W; Fraser, Peter

2015-08-26

Chromosome conformation capture and various derivative methods such as 4C, 5C and Hi-C have emerged as standard tools to analyze the three-dimensional organization of the genome in the nucleus. These methods employ ligation of diluted cross-linked chromatin complexes, intended to favor proximity-dependent, intra-complex ligation. During development of single-cell Hi-C, we devised an alternative Hi-C protocol with ligation in preserved nuclei rather than in solution. Here we directly compare Hi-C methods employing in-nucleus ligation with the standard in-solution ligation. We show in-nucleus ligation results in consistently lower levels of inter-chromosomal contacts. Through chromatin mixing experiments we show that a significantly large fraction of inter-chromosomal contacts are the result of spurious ligation events formed during in-solution ligation. In-nucleus ligation significantly reduces this source of experimental noise, and results in improved reproducibility between replicates. We also find that in-nucleus ligation eliminates restriction fragment length bias found with in-solution ligation. These improvements result in greater reproducibility of long-range intra-chromosomal and inter-chromosomal contacts, as well as enhanced detection of structural features such as topologically associated domain boundaries. We conclude that in-nucleus ligation captures chromatin interactions more consistently over a wider range of distances, and significantly reduces both experimental noise and bias. In-nucleus ligation creates higher quality Hi-C libraries while simplifying the experimental procedure. We suggest that the entire range of 3C applications are likely to show similar benefits from in-nucleus ligation.

The development of Fournier's gangrene following rubber band ligation of haemorrhoids

PubMed Central

Subramaniam, Daryl; Hureibi, Khalid; Zia, Khawaja; Uheba, Mokthar

2013-01-01

The development of Fournier's gangrene in an 80-year-old male patient with diabetes after a routine outpatient haemorrhoid banding procedure is described. Four days following the procedure, the patient noticed an increasing amount of pain and swelling of the perianal region. When the patient presented to the emergency department 18 days later, immediate radical debridement of ischiorectal necrotic tissue was performed. A defunctioning loop sigmoid colostomy was also formed. Subsequent operations required excision of the scrotum and abdominoperineal excision of the rectum. Histology studies later confirmed the presence of necrotising fasciitis. The case acts as a reminder that clinicians should maintain a high index of suspicion for high-risk patients still suffering from problems following the procedure. PMID:24287481

Pancreatic transplantation for diabetes mellitus. Discussion of indications and surgical technique with reference to 3 cases.

PubMed

Lundgren, G; Arnep, P; Groth, C G; Hårdstedt, C; Lewander, R; Ringdén, O; Ostman, J

Three patients reveived segmental pancreatic transplants. In two the main indication was hyperlabile diabetes, and in the third progressive loss of vision. Vascular anastomoses were to the iliac vessels, the graft being placed extraperitoneally. The pancreatic duct was ligated in the first case, while the other two, the transected end of the pancreatic graft was implanted into a jejunal Roux-Y loop. Two of the patients had normal blood glucose levels without insulin administration for 40 and 35 days, respectively. The grafts then underwent rejection and were removed. In both cases the postoperative course was complicated by pancreatic fistulae. In the 3rd patient the graft failed on the day after operation, due to venous trombosis.

[Rare bile duct anatomy variant - Right bile duct intraparenchymal junction into the left bile duct].

PubMed

Gál, Adrián Róbert; Kalmár-Nagy, Károly; Fincsur, András; Horváth, Örs Péter; Vereczkei, András

2018-03-01

The authors present a case of a 67-year-old male patient, who previously had been diagnosed with a malignant liver tumor localized in segment II. He underwent bisegmentectomy (II and III) and partial IV segmentectomy. After the primary surgery jaundice developed, the level of bilirubin increased and after several imaging modalities reoperation was indicated. During the surgery a rare bile duct anatomy variant was found. The right hepatic duct joined the left duct in the parenchyma of the left lobe, and was ligated at the resection. As the liver hilum was not explored, the absence of the right duct was not discovered. Reconstruction of the biliary system was accomplished by a Roux-en-Y loop.

Inflammation as a Driver of Clonal Evolution in Myeloproliferative Neoplasm

DTIC Science & Technology

2017-10-01

ligation due to a defect in the negative regulatory feedback loop which normally serves to dampen TNF production . We have localized this defect to a...excessive inflammatory cytokine production in MPN. 15. SUBJECT TERMS Myeloproliferative neoplasm, JAK2V617F, IL-10, TNF, inflammation 16. SECURITY...4 4. Impact…………………………...……………………………………9 5. Changes/Problems...….………………………………………………11 6. Products …………………………………….……….….…………….12 7

Plasmadiafiltration ameliorating gut mucosal barrier dysfunction and improving survival in porcine sepsis models.

PubMed

Li, Ming Xin; Liu, Jun Feng; Lu, Jian Da; Zhu, Ying; Kuang, Ding Wei; Xiang, Jian Bing; Sun, Peng; Wang, Wei; Xue, Jun; Gu, Yong; Hao, Chuan Ming

2016-12-01

The object of this study is to explore whether the plasmadiafiltration (PDF) is more effective in improving the intestinal mucosal barrier function by removing more key large molecular inflammatory mediators and then prolonging the survival time. Totally, 24 porcine sepsis models induced by cecal ligation and puncture (CLP) operation were randomly divided into three groups: PDF group, high-volume hemofiltration (HVHF) group, and control group, and received 8 h treatment, respectively. The expression of ZO-1 and occludin in intestinal mucosal epithelial cells were detected by immunohistochemistry, and apoptotic protein caspase-3-positive lymphocytes were signed in mesenteric lymph nodes by TUNEL staining. The hemodynamic parameters were measured by invasive cavity detection. The tumor necrosis factor alpha (TNFα) and high-mobility group protein 1 (HMGB1) were tested by ELISA method. And then, the survival curves with all-cause death were compared with three groups. PDF led to a superior reversal of sepsis-related hemodynamic impairment and serum biochemistry abnormalities and resulted in longer survival time compared with HVHF and control (p < 0.01). Definitive protection from excessive TNF-α and HMGB1 response were only achieved by PDF. A more regular distribution pattern of ZO-1 and occludin along the epithelium was found in PDF animals (p < 0.01). The presence of apoptotic lymphocytes was significantly reduced in the PDF animals (p < 0.01). PDF can effectively eliminate more pivotal inflammatory mediators of TNFα and HMGB1 and reduce the inflammation damage of the intestinal mucosal barrier and apoptosis of lymphocyte then improve the circulation function and prolong the survival time.

Cotransporting Ion is a Trigger for Cellular Endocytosis of Transporter-Targeting Nanoparticles: A Case Study of High-Efficiency SLC22A5 (OCTN2)-Mediated Carnitine-Conjugated Nanoparticles for Oral Delivery of Therapeutic Drugs.

PubMed

Kou, Longfa; Yao, Qing; Sun, Mengchi; Wu, Chunnuan; Wang, Jia; Luo, Qiuhua; Wang, Gang; Du, Yuqian; Fu, Qiang; Wang, Jian; He, Zhonggui; Ganapathy, Vadivel; Sun, Jin

2017-09-01

OCTN2 (SLC22A5) is a Na + -coupled absorption transporter for l-carnitine in small intestine. This study tests the potential of this transporter for oral delivery of therapeutic drugs encapsulated in l-carnitine-conjugated poly(lactic-co-glycolic acid) (PLGA) nanoparticles (LC-PLGA NPs) and discloses the molecular mechanism for cellular endocytosis of transporter-targeting nanoparticles. Conjugation of l-carnitine to a surface of PLGA-NPs enhances the cellular uptake and intestinal absorption of encapsulated drug. In both cases, the uptake process is dependent on cotransporting ion Na + . Computational OCTN2 docking analysis shows that the presence of Na + is important for the formation of the energetically stable intermediate complex of transporter-Na + -LC-PLGA NPs, which is also the first step in cellular endocytosis of nanoparticles. The transporter-mediated intestinal absorption of LC-PLGA NPs occurs via endocytosis/transcytosis rather than via the traditional transmembrane transport. The portal blood versus the lymphatic route is evaluated by the plasma appearance of the drug in the control and lymph duct-ligated rats. Absorption via the lymphatic system is the predominant route in the oral delivery of the NPs. In summary, LC-PLGA NPs can effectively target OCTN2 on the enterocytes for enhancing oral delivery of drugs and the critical role of cotransporting ions should be noticed in designing transporter-targeting nanoparticles. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of ligation method on maxillary arch force/moment systems for a simulated lingual incisor malalignment.

PubMed

Seru, Surbhi; Romanyk, Dan L; Toogood, Roger W; Carey, Jason P; Major, Paul W

2014-01-01

The objectives of this study were to determine whether there is a difference in the magnitude of forces and moments produced by elastic ligation when compared to passive ligation, and whether these forces and moments propagate differently along the arch for the two ligation types. A lingual incisor malalignment was used in this study. The Orthodontic Simulator (OSIM) was used to quantify the three-dimensional forces and moments applied on the teeth given a lingually displaced incisor. A repeated measures MANOVA was performed to statistically analyze the data. The interaction factor illustrated convincing evidence that there is a difference in maximum force and moment values for all outcome variables between ligation types considering all tooth positions along the arch. The mean differences for FX and FY between ligation types were found to be clinically significant, with values for elastic ligation consistently higher than passive ligation. It was found that the maximum forces and moments produced by elastic ligation are greater than those produced by passive ligation and that the magnitude of this difference for the mesiodistal and buccolingual forces is clinically relevant. Additionally, it was determined that elastic ligation causes forces and moments to propagate further along the arch than passive ligation for all outcome variables.

Proinflammatory Liver and Antiinflammatory Intestinal Mediators Involved in Portal Hypertensive Rats

PubMed Central

Aller, Maria Angeles; Vara, Elena; Garcia, Cruz; Palma, Maria Dolores; Arias, Jorge L.; Nava, Maria Paz; Arias, Jaime

2005-01-01

Proinflammatory (TNF-α, IL-1β, and NO) and antiinflammatory (IL-10, CO) levels were assayed in serum, liver, and small bowel in order to verify a hypothetic inflammatory etiopathogeny of portal hypertension that could be the cause of its evolutive heterogeneity. Male Wistar rats were divided into one control group (n = 11) and one group with a triple stenosing ligation of the portal vein (n = 23) after 28 days of evolution. In one subgroup of portal hypertensive rats, portal pressure, collateral venous circulation, mesenteric vasculopathy, and liver and spleen weights were determined. In the remaining rats with portal hypertension TNF-α, IL-1β, and IL-10 were quantified in liver and ileum by enzyme-linked immunosorbent assay. NO synthase activity was studied in liver and ileum. CO and NO were measured in portal and systemic blood by spectrophotometry and Griess reaction, respectively. Portal hypertensive rats with mayor spleen weight show hepatomegaly and mayor development of collateral circulation. Ileum release of IL-10 (0.30 ± 0.12 versus 0.14 ± 0.02 pmol/mg protein; P < .01) is associated with a liver production of both proinflammatory mediators (TNF-α: 2 ± 0.21 versus 1.32 ± 0.60 pmol/mg protein; P < .05, IL-1β: 19.17 ± 2.87 versus 5.96 ± 1.84 pmol/mg protein; P = .005, and NO: 132.10 ± 34.72 versus 61.05 ± 8.30 nmol/mL; P = .005) and an antiinflammatory mediator (CO: 6.49 ± 2.99 versus 3.03 ± 1.59 pmol/mL; P = .005). In short-term prehepatic portal hypertension a gut-liver inflammatory loop, which could be fundamental in the regulation both of the portal pressure and of its complications, could be proposed. PMID:16030393

Study on the release of fenofibrate nanosuspension in vitro and its correlation with in situ intestinal and in vivo absorption kinetics in rats.

PubMed

Xu, Yuanlong; Wang, Yonglu; Li, Xue Ming; Huang, Qinqin; Chen, Wei; Liu, Ran; Chen, BaoAn; Wei, Ping

2014-07-01

As an oral delivery carrier for poorly water soluble drugs, the nanosuspension was prepared by melt emulsification method combined with high-pressure homogenization. The objective of this study was to clarify the absorption mechanism in rats of fenofibrate nanosuspension using the model of in situ gut perfusion. The release rate of drug from nanosuspension was fast which about 70% of the drug would be released within 5 minutes. The absorption of fenofibrate nanosuspension in the gastrointestinal (GI) tract was studied by the in situ closed loop method in rats. It was found that the absorption process in intestine was first-process with passive diffusion mechanism, and the whole intestine was the major segment for the drug absorption. Additionally, GI absorption in situ studies indicated that the fenofibrate nanosuspension had great success in regard to enhancement of intestinal absorption compared to the fenofibrate suspension of coarse powder. The pharmacokinetic characteristics were studied in rats after oral administration of fenofibrate nanosuspension or suspension at the dosage of 27 mg/kg. The plasma concentration-time curve was fitted to the one-compartment model. The correlation between in vitro dissolution (P), in situ intestinal absorption (F) and in vivo absorption (Fa) in rats was investigated with the results as follows: Fa = 6.2061P-456.38(r = 0.9559), F = 3.6911P-2.2169(r = 0.970), F = 0.5095P + 44.189(r = 0.9609). The highest level A could be obtained from the in vitro--in vivo correlation (IVIVC) between dissolution percentage and intestinal absorption of the fenofibrate nanosuspension in rats. Consequently, the in situ intestinal perfusion model could be used to predict the in vivo pharmacokinetic characteristics in rats.

Molecular imaging analysis of intestinal insulin absorption boosted by cell-penetrating peptides by using positron emission tomography.

PubMed

Kamei, Noriyasu; Morishita, Mariko; Kanayama, Yousuke; Hasegawa, Koki; Nishimura, Mie; Hayashinaka, Emi; Wada, Yasuhiro; Watanabe, Yasuyoshi; Takayama, Kozo

2010-08-17

Molecular imaging technique by use of positron emission tomography (PET) is a noninvasive tool that allows one to quantitatively analyze the function of endogenous molecules and the pharmacokinetics of therapeutic agents in vivo. This technique is expected to be useful for evaluating the effectiveness of diverse drug delivery systems. We demonstrated previously that intestinal insulin absorption is increased significantly by coadministration of cell-penetrating peptides (CPPs), which are taken up effectively by several cells. However, the distribution behavior of insulin whose absorption is increased by CPPs is not clear. We used PET imaging and quantitatively analyzed the intestinal absorption and subsequent distribution of insulin and the effect of CPPs on its absorption and distribution. An unlabeled insulin solution containing tracer insulin, (68)Ga-DOTA-insulin, was administered with or without CPPs into a rat ileal closed loop. PET imaging showed that the CPPs, particularly D-R8 and L-penetratin, significantly increased the (68)Ga-DOTA-insulin level in the liver, kidney, and circulation. After absorption from the intestine, the (68)Ga-DOTA-insulin passed rapidly through the liver and accumulated in the kidney. The increase in the hepatic and renal distribution of (68)Ga-DOTA-insulin by each CPP coadministration was similar manner as that in intestinal absorption, suggesting that the increased accumulation of insulin in the liver and kidney induced by coadministration of CPPs was associated with the increased intestinal absorption of insulin. This is the first study to show that PET imaging enables one to quantitatively analyze the distribution behavior of intestinally absorbed insulin in several organs. This imaging methodology is likely to be useful for developing effective drug delivery systems targeted to specific organs. Copyright 2010 Elsevier B.V. All rights reserved.

Incidence of white spot lesions among patients treated with self- and conventional ligation systems.

PubMed

Akin, Mehmet; Tezcan, Mucella; Ileri, Zehra; Ayhan, Faruk

2015-07-01

The aim of this study was to investigate the incidence of white spot lesions (WSLs) and its relationship with various patient and treatment variables, in patients treated with self-ligation and conventional ligation orthodontic bracket systems. Two-hundred randomly selected patient records (136 female, 64 male) for self-ligation and (108 female, 92 male) for conventional ligation groups were examined to determine WSL development. In the self-ligation group, Damon 3MX (Ormco, Glendora, Calif) brackets had been used, and in the conventional ligation group, Equilibrium 2 (Dentaurum, Phorzeim, Germany) had been used. Labial surfaces of 24 teeth in the pre- and post-treatment photographic records were scored using the WSL index. The prevalence of patients who developed at least 1 WSL before treatment was 19%, whereas after treatment, it was 49% in the self-ligation and 54% in the conventional ligation groups. Before treatment, the patients had only mild WSL, but after treatment, severe WSL and cavitation were observed in both groups. Bracket type, age, and hygiene care were significantly associated with new WSL development (P = 0.008, P = 0.004, P = 0.013, respectively). Bracket type and more importantly, the hygiene care therapy provided appeared to influence the development of new WSLs. Ligation can promote plaque accumulation and thereby new WSL development in conventional bracket systems. This article investigates the incidence of WSLs in patients treated with self-ligation and conventional ligation. The present study showed that incidence of WSL less in the self-ligation than in the conventional ligation but hygiene care was mostly important factor in developed WSL.

Small bowel enteroclysis in surgically treated obesity.

PubMed

Coppola, V; Verrengia, D; Gatta, G; Alfinito, M; Alfano, L; D'Agostino, F

1998-11-01

To define the indications, technical limitations and diagnostic yeld of small bowel transbuccal enema in the follow-up of surgical jejunoileal shunting in patients with complicated severe essential obesity. Three patients were submitted to surgical diversion: two of them underwent an intestinal bypass after Payne-De Wind (isoperistaltic end-to-side jejunoileostomy) and the other after Scott (end-to-end jejunoileostomy). The latter refers to intestinal recanalization and antiperistaltic lower end-to-side gastroenteric restoration. Radiologic studies are the only means to depict the surgical small bowel. Radiographic follow-up needs barium sulfate administration and therefore cannot be performed any sooner than 30 days postoperatively. In the last three years the classic transbuccal enema has been performed with a Rollandi tube (with a terminal opening and a balloon). Both the anastomosis and the blind loop are difficult to demonstrate. Jejunoileal bypass can be used to treat severe obsity uncontrollable otherwise, to reduce food absorption. Different severe complications may result and small bowel studies may permit to show late local complications. Small bowel enema is also indispensable in bypass reversal. There are no alternatives to this radiologic examination which is however very difficult to perform, because of the changes made by previous operation(s), and to interpret because the anastomosis, the sutured loop and wall changes are often poorly demonstrated.

Water-Soluble Phosphinothiols for Traceless Staudinger Ligation and Integration with Expressed Protein Ligation

PubMed Central

Tam, Annie; Soellner, Matthew B.; Raines, Ronald T.

2010-01-01

The traceless Staudinger ligation is an effective means to synthesize an amide bond between two groups of otherwise orthogonal reactivity: a phosphinothioester and an azide. An important application of the Staudinger ligation is in the ligation of peptides at a variety of residues. Here, we demonstrate that the traceless Staudinger ligation can be achieved in water with a water-soluble reagent. Those reagents that provide a high yield of amide product discourage protonation of the nitrogen in the key iminophosphorane intermediate. The most efficacious reagent, bis(p-dimethylaminoethylphenyl)phosphinomethanethiol, mediates the rapid ligation of equimolar substrates in water. This reagent is also able to perform a transthioesterification reaction with the thioester intermediate formed during intein-mediated protein splicing. Hence, the traceless Staudinger ligation can be integrated with expressed protein ligation, extending the reach of modern protein chemistry. PMID:17713909

Analysis of maxillary arch force/couple systems for a simulated high canine malocclusion: Part 2. Elastic ligation.

PubMed

Fok, Jonathan; Toogood, Roger W; Badawi, Hisham; Carey, Jason P; Major, Paul W

2011-11-01

To better understand the mechanics of bracket/archwire interaction through analysis of force and couple distribution along the maxillary arch using elastic ligation and to compare these results with passive ligation. An orthodontic simulator was used to study a high canine malocclusion. Force and couple distributions produced by elastic ligation and round wire were measured. Forces and couples were referenced to the center of resistance of each tooth. Tests were repeated for 12 bracket sets with 12 wires per set. Data were compared with those derived from similar tests for passive ligation. Propagation of the force/couple systems around the arch using elastic ligation was extensive. Elastic ligation produced significantly more resistance to sliding, contributing to higher forces and couples at the center of resistance than were observed for passive ligation. The results of this study suggest some potential mechanical advantages of passive over elastic ligation. In particular, limited propagation around the arch in passive ligation reduces the occurrence of unwanted force/couple systems compared with elastic ligation. These advantages may not transfer to a clinical setting because of the conditions of the tests; additional testing would be required to determine whether these advantages can be generalized.

Parenteral glutamine supplementation in combination with enteral nutrition improves intestinal immunity in septic rats.

PubMed

Fan, Jun; Li, Guoping; Wu, Lidong; Tao, Shaoyu; Wang, Wei; Sheng, Zhiyong; Meng, Qingyan

2015-05-01

The gut-associated lymphoid tissue is continuously exposed to antigens in the gut lumen and becomes the first line of defense against enteric bacteria and associated toxin. The aim of this study was to investigate the effects of parenteral glutamine (GLN) supplementation in combination with enteral nutrition (EN) on intestinal mucosal immunity in septic rats by cecal ligation and puncture (CLP). Male Sprague-Dawley rats were randomly assigned into four groups: A sham CLP + EN + saline group (n = 10), a sham CLP + EN + GLN group (n = 10), a CLP + EN + saline group (n = 10), and a CLP + EN + GLN group (n = 10). At 2 h after CLP or sham CLP, all rats in each of the four groups received an identical enteral nutrition solution as their base formula. Then, the rats in the sham CLP + EN + GLN group and CLP + EN + GLN group were given 0.35 g GLN/kg body weight daily for 7 d, all at the same time, via a tail vein injection; whereas those in the sham CLP + EN + saline group and CLP + EN + saline group were daily administered isovolumic sterile 0.9% saline for comparison. All rats in each of the four groups were given 290 kcal/kg body wt/d for 7 d. At the end of the seventh day after the nutritional program was finished, all rats were euthanized and the entire intestine was collected. Total Peyer's patches (PP) cell yield was counted by a hemocytometer. The percentage of PP lymphocyte subsets was analyzed by flow cytometry. The number of intestinal lamina propria IgA plasma cells was determined by the immunohistochemistry technique. The intestinal immunoglobulin A (IgA) levels were assessed by ELISA. PP apoptosis was evaluated by terminal deoxyuridine nick-end labeling. The results revealed total PP cell yield, the numbers of PP lymphocyte subsets, intestinal lamina propria IgA plasma cells, and intestinal IgA levels in the CLP + EN + GLN group were significantly increased when compared with the CLP + EN + saline group (P < 0.05). On the other hand, the number of TUNEL-stained cells within PPs in the CLP + EN + GLN group was markedly decreased as compared with the CLP + EN + saline group (P < 0.05). The results of this study show that parenteral glutamine supplementation in combination with enteral nutrition may attenuate PP apoptosis, increase PP cell yield and intestinal lamina propria IgA plasma cells, and subsequently improve intestinal mucosal immunity. Clinically, these results suggest therapeutic efforts at improving intestinal immunity may contribute to the prevention and treatment of sepsis. Copyright © 2015 Elsevier Inc. All rights reserved.

Intestinal Glucose Absorption Was Reduced by Vertical Sleeve Gastrectomy via Decreased Gastric Leptin Secretion.

PubMed

Du, Jinpeng; Hu, Chaojie; Bai, Jie; Peng, Miaomiao; Wang, Qingbo; Zhao, Ning; Wang, Yu; Wang, Guobin; Tao, Kaixiong; Wang, Geng; Xia, Zefeng

2018-06-18

The unique effects of gastric resection after vertical sleeve gastrectomy (VSG) on type 2 diabetes mellitus remain unclear. This work aimed to investigate the effects of VSG on gastric leptin expression and intestinal glucose absorption in high-fat diet-induced obesity. Male C57BL/6J mice were fed a high-fat diet (HFD) to induce obesity. HFD mice were randomized into VSG and sham-operation groups, and the relevant parameters were measured at 8 weeks postoperation. Higher gastric leptin expression and increased intestinal glucose transport were observed in the HFD mice. Furthermore, VSG reduced gastric leptin expression and the intestinal absorption of alimentary glucose. Both exogenous leptin replenishment during the oral glucose tolerance test (OGTT) and the addition of leptin into the everted isolated jejunum loops in vitro restored the glucose transport capacity in VSG-operated mice, and this effect was abolished when the glucose transporter GLUT2 was blocked with phloretin. Moreover, phloretin almost completely suppressed glucose transport in the HFD mice. Intestinal immunohistochemistry in the obese mice showed increased GLUT2 and diminished sodium glucose co-transporter 1 (SGLT-1) in the apical membrane of enterocytes. Decreased GLUT2 and enhanced SGLT1 were observed following VSG. VSG also reduced the phosphorylation status of protein kinase C isoenzyme β II (PKCβ II) in the jejunum, which was stimulated by the combination of leptin and glucose. Our data demonstrated that the decreased secretion of gastric leptin in VSG results in a decrease in intestinal glucose absorption via modulation of GLUT2 translocation.

Graded effects of unregulated smooth muscle myosin on intestinal architecture, intestinal motility and vascular function in zebrafish.

PubMed

Abrams, Joshua; Einhorn, Zev; Seiler, Christoph; Zong, Alan B; Sweeney, H Lee; Pack, Michael

2016-05-01

Smooth muscle contraction is controlled by the regulated activity of the myosin heavy chain ATPase (Myh11). Myh11 mutations have diverse effects in the cardiovascular, digestive and genitourinary systems in humans and animal models. We previously reported a recessive missense mutation, meltdown (mlt), which converts a highly conserved tryptophan to arginine (W512R) in the rigid relay loop of zebrafish Myh11. The mlt mutation disrupts myosin regulation and non-autonomously induces invasive expansion of the intestinal epithelium. Here, we report two newly identified missense mutations in the switch-1 (S237Y) and coil-coiled (L1287M) domains of Myh11 that fail to complement mlt Cell invasion was not detected in either homozygous mutant but could be induced by oxidative stress and activation of oncogenic signaling pathways. The smooth muscle defect imparted by the mlt and S237Y mutations also delayed intestinal transit, and altered vascular function, as measured by blood flow in the dorsal aorta. The cell-invasion phenotype induced by the three myh11 mutants correlated with the degree of myosin deregulation. These findings suggest that the vertebrate intestinal epithelium is tuned to the physical state of the surrounding stroma, which, in turn, governs its response to physiologic and pathologic stimuli. Genetic variants that alter the regulation of smooth muscle myosin might be risk factors for diseases affecting the intestine, vasculature, and other tissues that contain smooth muscle or contractile cells that express smooth muscle proteins, particularly in the setting of redox stress. © 2016. Published by The Company of Biologists Ltd.

Laparoscopic intestinal derotation: original technique.

PubMed

Valle, Mario; Federici, Orietta; Tarantino, Enrico; Corona, Francesco; Garofalo, Alfredo

2009-06-01

The intestinal derotation technique, introduced by Cattel and Valdoni 40 years ago, is carried out using a laparoscopic procedure, which is described here for the first time. The method is effective in the treatment of malign lesions of the III and IV duodenum and during laparoscopic subtotal colectomy with anastomosis between the ascending colon and the rectum. Ultimately, the procedure allows for the verticalization of the duodenal C and the anterior positioning of the mesenteric vessels, facilitating biopsy and resection of the III and IV duodenal portions and allowing anastomosis of the ascending rectum, avoiding both subtotal colectomy and the risk of torsion of the right colic loop. Although the procedure calls for extensive experience with advanced video-laparoscopic surgery, it is both feasible and repeatable. In our experience we have observed no mortality or morbidity.

Tubal ligation

MedlinePlus

... tying; Tying the tubes; Hysteroscopic tubal occlusion procedure; Contraception - tubal ligation; Family planning - tubal ligation ... Tubal ligation is considered a permanent form of birth control. It is NOT recommended as a short-term ...

Intestinal absorption of medium chain fatty acids: in vivo studies in pigs devoid of exocrine pancreatic secretion.

PubMed

Guillot, E; Lemarchal, P; Dhorne, T; Rerat, A

1994-10-01

In order to study the influence of pancreatic enzyme secretion on the intestinal absorption of medium-chain fatty acids (MCFA), three growing pigs (mean body-weight 61 kg) with ligated and severed pancreatic ducts were fitted with a permanent fistula in the duodenum and with two catheters in the portal vein and carotid artery respectively. An electromagnetic flow probe was also set up around the portal vein. A mixture of octanoic and decanoic acids, esterified as medium-chain triacylglycerols, together with maltose dextrine and nitrogenous fraction was continuously infused for 1 h into the duodenum. Samples of blood were withdrawn from the two vessels at regular intervals of time for 8 h and further analysed for their non-esterified octanoic and decanoic acid contents. The concentrations of non-esterified octanoic and decanoic acid in the portal blood increased slowly after the beginning of each infusion, reaching about 10 times higher values than the basal level. Only 26% of octanoic acid infused in the duodenum and 27% of decanoic acid were recovered in the portal flow throughout each experiment. The possible mechanisms underlying the appearance of MCFA in the portal blood in the absence of pancreatic enzyme secretions and the importance of duodenal absorption of MCT in such physiological conditions have been discussed.

Effect of Obstructive Jaundice and Nitric Oxide on the Profiles of Intestinal Bacterial Flora in Wild and iNOS−/− Mice

PubMed Central

Hong, Ji-Young; F. Sato, Eisuke; Nishikawa, Tomoko; Hiramoto, Keiichi; Inoue, Masayasu

2009-01-01

We previously reported that the plasma level of endotoxin and colonic expression of IgA in the mouse increased with obstructive jaundice induced by bile duct ligation (BDL). To elucidate the mechanism of the BDL-induced increase, we analyzed the effect of BDL on intestinal flora in wild type and inducible nitric oxide synthase (iNOS)-deficient mice (iNOS−/−) using the terminal restriction fragment length polymorphism analysis (T-RFLP) and 16S rDNA clone libraries. The amounts of bacterial DNA detected in fecal samples from both animal groups pretreated with antibiotics were extremely low as compared with untreated groups. We found that the profiles of enteric bacteria changed markedly after BDL. The bacterial composition is significantly different between not only wild type and iNOS−/− mice but also those before and after BDL, respectively. Among enteric bacteria examined, Lactobacillus murinus was found to increase markedly after BDL in rectum of both animal groups. However, Escherichia coli markedly increased after BDL in the iNOS−/− mice. These findings suggest that profiles of enteric flora change markedly in animals during obstructive jaundice by some mechanism that is affected by bile constituents and iNOS-derived NO. PMID:19308270

Propolis reduces bacterial translocation and intestinal villus atrophy in experimental obstructive jaundice

PubMed Central

Sabuncuoglu, Mehmet Zafer; Kismet, Kemal; Kilicoglu, Sibel Serin; Kilicoglu, Bulent; Erel, Serap; Muratoglu, Sabahattin; Sunay, Asli Elif; Erdemli, Esra; Akkus, Mehmet Ali

2007-01-01

AIM: To investigate the effects of propolis on bacterial translocation and ultrastructure of intestinal morphology in experimental obstructive jaundice. METHODS: Thirty Wistar-Albino male rats were randomly divided into three groups, each including 10 animals: groupI, sham-operated; group II, ligation and division of the common bile duct (BDL); group III, BDL followed by oral supplementation of propolis 100 mg/kg per day. Liver, blood, spleen, mesenteric lymph nodes, and ileal samples were taken for microbiological, light and transmission electron microscopic examination on postoperative 7th d after sacrification. RESULTS: The mean number of villi per centimeter and mean mucosal height of the propolis group were significantly different in the BDL group (P = 0.001 and 0.012, respectively). The electron microscopic changes were also different between these groups. Sham and BDL + propolis groups had similar incidence of bacterial translocation (BT). The BDL group had significantly higher rates of BT as compared with sham and BDL + propolis groups. BT was predominantly detected in MLNs and the most commonly isolated bacteria was Escherichia coli. CONCLUSION: Propolis showed a significant protective effect on ileal mucosa and reduced bacterial translocation in the experimental obstructive jaundice model. Further studies should be carried out to explain the mechanisms of these effects. PMID:17876893

Fidaxomicin Inhibits Clostridium difficile Toxin A-Mediated Enteritis in the Mouse Ileum

PubMed Central

Koon, Hon Wai; Ho, Samantha; Hing, Tressia C.; Cheng, Michelle; Chen, Xinhua; Ichikawa, Yoshi; Kelly, Ciarán P.

2014-01-01

Clostridium difficile infection (CDI) is a common, debilitating infection with high morbidity and mortality. C. difficile causes diarrhea and intestinal inflammation by releasing two toxins, toxin A and toxin B. The macrolide antibiotic fidaxomicin was recently shown to be effective in treating CDI, and its beneficial effect was associated with fewer recurrent infections in CDI patients. Since other macrolides possess anti-inflammatory properties, we examined the possibility that fidaxomicin alters C. difficile toxin A-induced ileal inflammation in mice. The ileal loops of anesthetized mice were injected with fidaxomicin (5, 10, or 20 μM), and after 30 min, the loops were injected with purified C. difficile toxin A or phosphate-buffered saline alone. Four hours after toxin A administration, ileal tissues were processed for histological evaluation (epithelial cell damage, neutrophil infiltration, congestion, and edema) and cytokine measurements. C. difficile toxin A caused histologic damage, evidenced by increased mean histologic score and ileal interleukin-1β (IL-1β) protein and mRNA expression. Treatment with fidaxomicin (20 μM) or its primary metabolite, OP-1118 (120 μM), significantly inhibited toxin A-mediated histologic damage and reduced the mean histology score and ileal IL-1β protein and mRNA expression. Both fidaxomicin and OP-1118 reduced toxin A-induced cell rounding in human colonic CCD-18Co fibroblasts. Treatment of ileal loops with vancomycin (20 μM) and metronidazole (20 μM) did not alter toxin A-induced histologic damage and IL-1β protein expression. In addition to its well known antibacterial effects against C. difficile, fidaxomicin may possess anti-inflammatory activity directed against the intestinal effects of C. difficile toxins. PMID:24890583

Chemical Ligation Reactions of Oligonucleotides for Biological and Medicinal Applications.

PubMed

Abe, Hiroshi; Kimura, Yasuaki

2018-01-01

Chemical ligation of oligonucleotides (ONs) is the key reaction for various ON-based technologies. We have tried to solve the problems of RNA interference (RNAi) technology by applying ON chemical ligation to RNAi. We designed a new RNAi system, called intracellular buildup RNAi (IBR-RNAi), where the RNA fragments are built up into active small-interference RNA (siRNA) in cells through a chemical ligation reaction. Using the phosphorothioate and iodoacetyl groups as reactive functional groups for the ligation, we achieved RNAi effects without inducing immune responses. Additionally, we developed a new chemical ligation for IBR-RNAi, which affords a more native-like structure in the ligated product. The new ligation method should be useful not only for IBR-RNAi but also for the chemical synthesis of biofunctional ONs.

Modified Multivisceral Transplant After Acute Abdominal Trauma.

PubMed

Nikeghbalian, Saman; Alaa Eldin, Ahmed; Aliakbarian, Mohsen; Kazemi, Kourosh; Shamsaeefar, Alireza; Gholami, Siavash; Malekhosseini, Seyed Ali

2016-04-01

A 50-year-old man sustained blunt abdominal trauma in a motor vehicle accident. He underwent exploratory laparotomy on the day of trauma, and severe bleeding from the base of the small bowel mesentery was controlled by mass ligation and through-and-through suturing. After transfer to our center, repeat exploratory laparotomy showed ischemic small intestine, ischemic right colon, and severe pancreatic trauma. The severely injured organs were excised including the entire small bowel, pancreas, spleen, stomach, and right hemicolon. The next day, a modified multivisceral transplant was performed including stomach, pancreaticoduodenal complex, and small bowel transplant. Postoperative complications included an intra-abdominal collection that was drained percutaneously with ultrasonographic guidance and severe rejection that was treated with anti-thymocyte globulin. In summary, for select patients who have severe abdominal trauma may be treated with acute multivisceral transplant.

Chronic alcohol ingestion increases mortality and organ injury in a murine model of septic peritonitis.

PubMed

Yoseph, Benyam P; Breed, Elise; Overgaard, Christian E; Ward, Christina J; Liang, Zhe; Wagener, Maylene E; Lexcen, Daniel R; Lusczek, Elizabeth R; Beilman, Greg J; Burd, Eileen M; Farris, Alton B; Guidot, David M; Koval, Michael; Ford, Mandy L; Coopersmith, Craig M

2013-01-01

Patients admitted to the intensive care unit with alcohol use disorders have increased morbidity and mortality. The purpose of this study was to determine how chronic alcohol ingestion alters the host response to sepsis in mice. Mice were randomized to receive either alcohol or water for 12 weeks and then subjected to cecal ligation and puncture. Mice were sacrificed 24 hours post-operatively or followed seven days for survival. Septic alcohol-fed mice had a significantly higher mortality than septic water-fed mice (74% vs. 41%, p = 0.01). This was associated with worsened gut integrity in alcohol-fed mice with elevated intestinal epithelial apoptosis, decreased crypt proliferation and shortened villus length. Further, alcohol-fed mice had higher intestinal permeability with decreased ZO-1 and occludin protein expression in the intestinal tight junction. The frequency of splenic and bone marrow CD4+ T cells was similar between groups; however, splenic CD4+ T cells in septic alcohol-fed mice had a marked increase in both TNF and IFN-γ production following ex vivo stimulation. Neither the frequency nor function of CD8+ T cells differed between alcohol-fed and water-fed septic mice. NK cells were decreased in both the spleen and bone marrow of alcohol-fed septic mice. Pulmonary myeloperoxidase levels and BAL levels of G-CSF and TFG-β were higher in alcohol-fed mice. Pancreatic metabolomics demonstrated increased acetate, adenosine, xanthine, acetoacetate, 3-hydroxybutyrate and betaine in alcohol-fed mice and decreased cytidine, uracil, fumarate, creatine phosphate, creatine, and choline. Serum and peritoneal cytokines were generally similar between alcohol-fed and water-fed mice, and there were no differences in bacteremia, lung wet to dry weight, or pulmonary, liver or splenic histology. When subjected to the same septic insult, mice with chronic alcohol ingestion have increased mortality. Alterations in intestinal integrity, the host immune response, and pancreatic metabolomics may help explain this differential response.

The role of patent ductus arteriosus ligation in bronchopulmonary dysplasia: reexamining a randomized controlled trial.

PubMed

Clyman, Ronald; Cassady, George; Kirklin, James K; Collins, Monica; Philips, Joseph B

2009-06-01

To reexamine data from a randomized controlled trial of prophylactic ductus ligation to determine whether ligation contributes directly to the development of bronchopulmonary dysplasia (BPD) in extremely low birth weight infants. The control group underwent ligation only if they had development of a symptomatic patent ductus arteriosus (PDA). The Prophylactic Ligation group underwent ligation within 24 hours of birth regardless of the presence or absence of symptoms of a PDA. We hypothesized that the incidence of BPD would be higher in the prophylactic ligation group because more ligations were performed than in the control group. Prophylactic ligation significantly increased the incidence of BPD (defined as a supplemental oxygen requirement at 36 weeks postmenstrual age) and the incidence of mechanical ventilation at 36 weeks. The groups were statistically similar in gestation, sex, race, fluid administration, intraventricular hemorrhage, pulmonary air leaks, and survival to 36 weeks. The lower incidence of BPD in the control group occurred despite the fact that the incidence of necrotizing enterocolitis (a known risk factor for BPD) was significantly elevated in the control group. Only infants who had previously undergone a PDA ligation had development of BPD in the control group. Prophylactic ligation, while eliminating the PDA, increases the risk for BPD.

Palindromic Sequence Artifacts Generated during Next Generation Sequencing Library Preparation from Historic and Ancient DNA

PubMed Central

Star, Bastiaan; Nederbragt, Alexander J.; Hansen, Marianne H. S.; Skage, Morten; Gilfillan, Gregor D.; Bradbury, Ian R.; Pampoulie, Christophe; Stenseth, Nils Chr; Jakobsen, Kjetill S.; Jentoft, Sissel

2014-01-01

Degradation-specific processes and variation in laboratory protocols can bias the DNA sequence composition from samples of ancient or historic origin. Here, we identify a novel artifact in sequences from historic samples of Atlantic cod (Gadus morhua), which forms interrupted palindromes consisting of reverse complementary sequence at the 5′ and 3′-ends of sequencing reads. The palindromic sequences themselves have specific properties – the bases at the 5′-end align well to the reference genome, whereas extensive misalignments exists among the bases at the terminal 3′-end. The terminal 3′ bases are artificial extensions likely caused by the occurrence of hairpin loops in single stranded DNA (ssDNA), which can be ligated and amplified in particular library creation protocols. We propose that such hairpin loops allow the inclusion of erroneous nucleotides, specifically at the 3′-end of DNA strands, with the 5′-end of the same strand providing the template. We also find these palindromes in previously published ancient DNA (aDNA) datasets, albeit at varying and substantially lower frequencies. This artifact can negatively affect the yield of endogenous DNA in these types of samples and introduces sequence bias. PMID:24608104

The cell pole: the site of cross talk between the DNA uptake and genetic recombination machinery.

PubMed

Kidane, Dawit; Ayora, Silvia; Sweasy, Joann B; Graumann, Peter L; Alonso, Juan C

2012-01-01

Natural transformation is a programmed mechanism characterized by binding of free double-stranded (ds) DNA from the environment to the cell pole in rod-shaped bacteria. In Bacillus subtilis some competence proteins, which process the dsDNA and translocate single-stranded (ss) DNA into the cytosol, recruit a set of recombination proteins mainly to one of the cell poles. A subset of single-stranded binding proteins, working as "guardians", protects ssDNA from degradation and limit the RecA recombinase loading. Then, the "mediators" overcome the inhibitory role of guardians, and recruit RecA onto ssDNA. A RecA·ssDNA filament searches for homology on the chromosome and, in a process that is controlled by "modulators", catalyzes strand invasion with the generation of a displacement loop (D-loop). A D-loop resolvase or "resolver" cleaves this intermediate, limited DNA replication restores missing information and a DNA ligase seals the DNA ends. However, if any step fails, the "rescuers" will repair the broken end to rescue chromosomal transformation. If the ssDNA does not share homology with resident DNA, but it contains information for autonomous replication, guardian and mediator proteins catalyze plasmid establishment after inhibition of RecA. DNA replication and ligation reconstitute the molecule (plasmid transformation). In this review, the interacting network that leads to a cross talk between proteins of the uptake and genetic recombination machinery will be placed into prospective.

The cell pole: The site of cross talk between the DNA uptake and genetic recombination machinery

PubMed Central

Kidane, Dawit; Ayora, Silvia; Sweasy, Joann; Graumann, Peter L.; Alonso, Juan C.

2012-01-01

Natural transformation is a programmed mechanism characterized by binding of free double-stranded (ds) DNA from the environment to the cell pole in rod-shaped bacteria. In Bacillus subtilis some competence proteins, which process the dsDNA and translocate single-stranded (ss) DNA into the cytosol, recruit a set of recombination proteins mainly to one of the cell poles. A subset of single-stranded binding proteins, working as “guardians”, protect ssDNA from degradation and limit the RecA recombinase loading. Then, the “mediators” overcome the inhibitory role of guardians, and recruit RecA onto ssDNA. A RecA·ssDNA filament searches for homology on the chromosome and, in a process that is controlled by “modulators”, catalyzes strand invasion with the generation of a displacement loop (D-loop). A D-loop resolvase or “resolver” cleaves this intermediate, limited DNA replication restores missing information and a DNA ligase seals the DNA ends. However, if any step fails, the “rescuers” will repair the broken end to rescue chromosomal transformation. If the ssDNA does not share homology with resident DNA, but it contains information for autonomous replication, guardian and mediator proteins catalyze plasmid establishment after inhibition of RecA. DNA replication and ligation reconstitute the molecule (plasmid transformation). In this review, the interacting network that leads to a cross talk between proteins of the uptake and genetic recombination machinery will be placed into prospective. PMID:23046409

[Latex ligation in treatment of chronic hemorrhoids].

PubMed

Ektov, V N; Somov, K A

2015-01-01

We analyzed the results of treatment of 432 patients with chronic hemorrhoids using different variants of latex ligation. New technique including ligation of mucosa and submucosa of low-ampullar rectum providing ligation of hemorrhoidalvessels, lifting and recto-anal repair is developed and suggested. This method is advisable to use in case of chronic internal hemorrhoids stages I and II. The authors recommend simultaneous combined ligation of mucosa of low-ampullar rectum and internal hemorrhoids for stages III and IV. Different variants of latex ligation with external hemorrhoids excision were used in 103 patients. Pointed variants of latex ligation preserve important advantages including mini-invasiveness, simplicity and wide availability, low cost. Good remote results were obtained after these procedures in 87.3% of observations. Suggested tactics extends use of latex ligation and increases its effectiveness in treatment of different stages and forms of chronic hemorrhoids.

Active intestinal absorption of fluoroquinolone antibacterial agent ciprofloxacin by organic anion transporting polypeptide, Oatp1a5.

PubMed

Arakawa, Hiroshi; Shirasaka, Yoshiyuki; Haga, Makoto; Nakanishi, Takeo; Tamai, Ikumi

2012-09-01

Fluoroquinolone antimicrobial drugs are absorbed efficiently after oral administration despite of their hydrophilic nature, implying an involvement of carrier-mediated transport in their membrane transport process. It has been that several fluoroquinolones are substrates of organic anion transporter polypeptides OATP1A2 expressed in human intestine derived Caco-2 cells. In the present study, to clarify the involvement of OATP in intestinal absorption of ciprofloxacin, the contribution of Oatp1a5, which is expressed at the apical membranes of rat enterocytes, to intestinal absorption of ciprofloxacin was investigated in rats. The intestinal membrane permeability of ciprofloxacin was measured by in situ and the vascular perfused closed loop methods. The disappeared and absorbed amount of ciprofloxacin from the intestinal lumen were increased markedly in the presence of 7,8-benzoflavone, a breast cancer resistance protein inhibitor, and ivermectin, a P-glycoprotein inhibitor, while it was decreased significantly in the presence of these inhibitors in combination with naringin, an Oatp1a5 inhibitor. Furthermore, the Oatp1a5-mediated uptake of ciprofloxacin was saturable with a K(m) value of 140 µm, and naringin inhibited the uptake with an IC(50) value of 18 µm by Xenopus oocytes expressing Oatp1a5. Naringin reduced the permeation of ciprofloxacin from the mucosal-to-serosal side, with an IC(50) value of 7.5 µm by the Ussing-type chamber method. The estimated IC(50) values were comparable to that of Oatp1a5. These data suggest that Oatp1a5 is partially responsible for the intestinal absorption of ciprofloxacin. In conclusion, the intestinal absorption of ciprofloxacin could be affected by influx transporters such as Oatp1a5 as well as the efflux transporters such as P-gp and Bcrp. Copyright © 2012 John Wiley & Sons, Ltd.

Molecular weight dependence of permselectivity to rat small intestinal blood-lymph barrier for exogenous macromolecules absorbed from lumen.

PubMed

Yoshikawa, H; Takada, K; Muranishi, S

1984-01-01

The permselectivity to the small intestinal blood-lymph barrier for the exogenous macromolecules absorbed from the lumen was investigated using in situ rat closed loop experiment. We chose the fluorescein isothiocyanate-labelled dextran (FD) as macromolecule and lipid-surfactant mixed micelles as an absorption promoter. The mean molecular weights of FDs used were 10500, 17500, 39000 and 64200 (abbreviated: FD10 , 20, 40 and 70). The lymph/plasma ratios of FDs concentrations during 5 h post administration were 0.2-1.2 ( FD10 ), 0.4-1.3 ( FD20 ), 1.3-7.2 ( FD40 ) and 2.6-11.9 ( FD70 ), respectively. The FD40 and FD70 levels in the lymph were significantly higher than those in the plasma. The cumulative amounts (% of the absorbed quantity) of FDs in the lymph from the lumen of the small intestine for 5 h after administration were 0.46% ( FD10 ), 0.51% ( FD20 ), 1.17% ( FD40 ) and 1.89% ( FD70 ), respectively. These findings suggest that the threshold molecular weight of FD for the transfer into the lymphatics with higher level compared to the blood concentration from the lumen across the small intestinal blood-lymph barrier exists between 17500 and 39000.

DUSP5 is methylated in CIMP-high colorectal cancer but is not a major regulator of intestinal cell proliferation and tumorigenesis.

PubMed

Tögel, Lars; Nightingale, Rebecca; Wu, Rui; Chüeh, Anderly C; Al-Obaidi, Sheren; Luk, Ian; Dávalos-Salas, Mercedes; Chionh, Fiona; Murone, Carmel; Buchanan, Daniel D; Chatterton, Zac; Sieber, Oliver M; Arango, Diego; Tebbutt, Niall C; Williams, David; Dhillon, Amardeep S; Mariadason, John M

2018-01-29

The ERK signalling pathway regulates key cell fate decisions in the intestinal epithelium and is frequently dysregulated in colorectal cancers (CRCs). Variations in the dynamics of ERK activation can induce different biological outcomes and are regulated by multiple mechanisms, including activation of negative feedback loops involving transcriptional induction of dual-specificity phosphatases (DUSPs). We have found that the nuclear ERK-selective phosphatase DUSP5 is downregulated in colorectal tumours and cell lines, as previously observed in gastric and prostate cancer. The DUSP5 promoter is methylated in a subset of CRC cell lines and primary tumours, particularly those with a CpG island methylator phenotype (CIMP). However, this epigenetic change alone could not account for reduced DUSP5 expression in CRC cells. Functionally, DUSP5 depletion failed to alter ERK signalling or proliferation in CRC cell lines, and its transgenic overexpression in the mouse intestine had minimal impact on normal intestinal homeostasis or tumour development. Our results suggest that DUSP5 plays a limited role in regulating ERK signalling associated with the growth of colorectal tumours, but that methylation the DUSP5 gene promoter can serve as an additional means of identifying CIMP-high colorectal cancers.

Adrenergic mediation of the intestinal antisecretory action of opiates administered into the central nervous system.

PubMed

Brown, D R; Miller, R J

1984-10-01

The antisecretory effects of the stable enkephalin analogs, [D-Ala2-Met5] enkephalinamide (DAMA) and [D-Ala2-D-Leu5] enkephalin, and the opiate drug morphine were evaluated on fluid secretion induced by cholera toxin in isolated loops of the jejunum and proximal and distal ileum in anesthetized rats. Intracerebroventricular administration of DAMA (0.03-3 micrograms) or [D-Ala2-D-Leu5] enkephalin (1.0-10 micrograms) dose-dependently reduced secretion in the jejunum without affecting fluid movement in the other small intestinal segments. Morphine in doses up to 30 micrograms i.c.v. had no significant antisecretory effects. Intravenous administration of DAMA, at doses up to 3000 micrograms/kg, had little effect on intestinal fluid accumulation. The antisecretory action of DAMA (3 micrograms i.c.v.) was completely blocked by pretreatment with the alpha adrenergic antagonist phentolamine and after peripheral sympathectomy induced by guanethidine. In contrast, DAMA activity was preserved in adrenal demedullated rats. DAMA had no significant effects upon mean arterial blood pressure or on blood acid-base balance. These results suggest that the antisecretory effects of opiates are, at least partly, mediated at sites within the central nervous system. These actions are probably a consequence of increased activity in sympathetic nerve fibers innervating the upper small intestine.

Suppression of intestinal tumorigenesis in Apc mutant mice upon Musashi-1 deletion.

PubMed

Wolfe, Andy R; Ernlund, Amanda; McGuinness, William; Lehmann, Carl; Carl, Kaitlyn; Balmaceda, Nicole; Neufeld, Kristi L

2017-02-15

Therapeutic strategies based on a specific oncogenic target are better justified when elimination of that particular oncogene reduces tumorigenesis in a model organism. One such oncogene, Musashi-1 ( Msi-1 ), regulates translation of target mRNAs and is implicated in promoting tumorigenesis in the colon and other tissues. Msi-1 targets include the tumor suppressor adenomatous polyposis coli ( Apc ), a Wnt pathway antagonist lost in ∼80% of all colorectal cancers. Cell culture experiments have established that Msi-1 is a Wnt target, thus positioning Msi-1 and Apc as mutual antagonists in a mutually repressive feedback loop. Here, we report that intestines from mice lacking Msi-1 display aberrant Apc and Msi-1 mutually repressive feedback, reduced Wnt and Notch signaling, decreased proliferation, and changes in stem cell populations, features predicted to suppress tumorigenesis. Indeed, mice with germline Apc mutations ( Apc Min ) or with the Apc 1322T truncation mutation have a dramatic reduction in intestinal polyp number when Msi-1 is deleted. Taken together, these results provide genetic evidence that Msi-1 contributes to intestinal tumorigenesis driven by Apc loss, and validate the pursuit of Msi-1 inhibitors as chemo-prevention agents to reduce tumor burden. © 2017. Published by The Company of Biologists Ltd.

Long-term safety of left renal vein division and ligation to expedite complex abdominal aortic surgery.

PubMed

Samson, Russell H; Lepore, Michael R; Showalter, David P; Nair, Deepak G; Lanoue, Julien B

2009-09-01

Left renal vein division and ligation (LRVDAL) is performed to facilitate complex abdominal aortic surgery. Surgeons restore continuity of the vein due to concern that ligation could cause renal compromise or hematuria. However, we report the short and long-term safety of left renal vein division and ligation. Between 1992 and 2007, we divided the left renal vein in 56 patients (40 males, 16 females) ages 57 to 84 (average 74-years-old) who were treated for aortic occlusive disease (9) or abdominal aortic aneurysm (47). Patients requiring concomitant renal artery reconstruction were excluded from this review. Suprarenal cross-clamp was used in 51 patients with temporary vessel-loop control of the renal arteries. Creatinine (Cr) and glomerular filtration rates (eGFR) were measured pre-, post-, and long-term after surgery. Outpatient records of all patients that had survived more than 12 months were also reviewed in order to evaluate the late effects on renal function or symptoms possibly related to LRVDAL. Median procedure duration was 157 (61-375) minutes. Median cross-clamp time was 16 (10-45) minutes. Median intensive care unit (ICU) and hospital length of stays were 2 (1-11) days and 7 (4-58) days, respectively. There were no deaths. There were no complications directly related to renal vein ligation. Hematuria, seen in 2 patients, was a result of traumatic insertion of a Foley catheter. Median pre-op and discharge Cr levels were 1.1 mg/dL (0.7-2.4 mg/dL) and 1.1 mg/dL (0.6-2.1 mg/dL), respectively (P < .5). Median change in Cr was 0.0 mg/dL and only increased in 14 patients (maximum increase 0.9 mg/dL). Median pre-op and discharge eGFR was 61 mL/minute (28-137 mL/minute/1.73 m2) and 67 mL/minute (32-138 mL/minute/1.73 m2), respectively (P < .5). Cr and eGFR in the 2 patients with a Cr of >2.0 mg/dL remained unchanged post-op. Only 2 patients with a Cr of <2.0 mg/dL had a post-op Cr >2.0 mg/dL and both returned to normal by day 3 post-op. Thirty-six patients have been followed for more than a year (median 34.5 months, maximum 144 months) and Cr has remained stable in all but 2 patients. These 2 patients, both with a pre-op Cr of 1.5 mg/dL, subsequently developed Cr levels of 2.1 mg/dL and 2.4 mg/dL but maintained baseline Cr levels for 25 and 34 months, respectively, before demonstrating these elevated levels which have proven to be unrelated to renal vein ligation. Hematuria and flank pain have never been recorded after discharge. Restoration of left renal vein continuity after LRVDAL may be unnecessary since renal compromise and hematuria was not encountered in this long-term analysis.

Quantitative mRNA analysis of muscarinic acetylcholine receptors in the intestine of dairy cows with spontaneous caecal dilatation-dislocation.

PubMed

Ontsouka, E C; Steiner, A; Bruckmaier, R M; Blum, J W; Meylan, M

2009-05-01

Muscarinic receptors mediate acetylcholine-induced muscular contractions. In this study, mRNA levels of muscarinic receptor subtypes 2 and 3 (M(2) and M(3)) in the ileum, caecum, proximal loop of the ascending colon (PLAC) and external loop of the spiral colon (ELSC) were determined by quantitative polymerase chain reaction in seven cows with caecal dilatation-dislocation (CDD) and seven healthy control cows. Levels of M(2) were significantly lower in the caecum, PLAC and ELSC and levels of M(3) were significantly lower in the ileum, caecum, PLAC and ELSC of cows with CDD compared to healthy cows (P<0.05). Down-regulation of M(3) may play a role in the pathogenesis of CDD.

Carrier-mediated transport of riboflavin in the rat colon.

PubMed

Yuasa, H; Hirobe, M; Tomei, S; Watanabe, J

2000-03-01

Carriers involved in riboflavin transport have generally been presumed to be localized in the upper small intestine. However, using a closed loop technique, we found that in the rat colon the absorption of riboflavin could be significantly reduced by raising the concentration from 0.1 to 200 microM and by adding lumiflavin, an analogue of riboflavin. These results suggest that saturable transport by the carrier that is specific for riboflavin and analogues may also be involved in riboflavin absorption in the colon. At the lower concentration of 0.1 microM, carrier-mediated transport was suggested to prevail, compared with passive transport, both in the colon and the small intestine. Furthermore, carrier-mediated transport in the colon was comparable with that in the small intestine. This study is the first to suggest carrier-mediated riboflavin transport in the colon. Although the riboflavin transport system in the colon needs to be subjected to more detailed investigation of its transport functions and role in riboflavin absorption after oral administration, it would be of interest to explore potential use of this carrier as a system for drug delivery.

RasGRP1 opposes proliferative EGFR–SOS1–Ras signals and restricts intestinal epithelial cell growth

PubMed Central

Depeille, Philippe; Henricks, Linda M.; van de Ven, Robert A. H.; Lemmens, Ed; Wang, Chih-Yang; Matli, Mary; Werb, Zena; Haigis, Kevin M.; Donner, David; Warren, Robert; Roose, Jeroen P.

2015-01-01

The character of EGFR signals can influence cell fate but mechanistic insights into intestinal EGFR-Ras signalling are limited. Here we show that two distinct Ras nucleotide exchange factors, RasGRP1 and SOS1, lie downstream of EGFR but act in functional opposition. RasGRP1 is expressed in intestinal crypts where it restricts epithelial growth. High RasGRP1 expression in colorectal cancer (CRC) patient samples correlates with a better clinical outcome. Biochemically, we find that RasGRP1 creates a negative feedback loop that limits proliferative EGFR–SOS1–Ras signals in CRC cells. Genetic Rasgrp1 depletion from mice with either an activating mutation in KRas or with aberrant Wnt signalling due to a mutation in Apc resulted in both cases in exacerbated Ras–ERK signalling and cell proliferation. The unexpected opposing cell biological effects of EGFR–RasGRP1 and EGFR–SOS1 signals in the same cell shed light on the intricacy of EGFR-Ras signalling in normal epithelium and carcinoma. PMID:26005835

Elucidating pathways of Toxoplasma gondii invasion in the gastrointestinal tract: involvement of the tight junction protein occludin.

PubMed

Weight, Caroline M; Jones, Emily J; Horn, Nikki; Wellner, Nikolaus; Carding, Simon R

2015-10-01

Toxoplasma gondii is an obligate intracellular parasite infecting one third of the world's population. The small intestine is the parasite's primary route of infection, although the pathway of epithelium transmigration remains unclear. Using an in vitro invasion assay and live imaging we showed that T. gondii (RH) tachyzoites infect and transmigrate between adjacent intestinal epithelial cells in polarized monolayers without altering barrier integrity, despite eliciting the production of specific inflammatory mediators and chemokines. During invasion, T. gondii co-localized with occludin. Reducing the levels of endogenous cellular occludin with specific small interfering RNAs significantly reduced the ability of T. gondii to penetrate between and infect epithelial cells. Furthermore, an in vitro invasion and binding assays using recombinant occludin fragments established the capacity of the parasite to bind occludin and in particular to the extracellular loops of the protein. These findings provide evidence for occludin playing a role in the invasion of T. gondii in small intestinal epithelial cells. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Protons act as a transmitter for muscle contraction in C. elegans.

PubMed

Beg, Asim A; Ernstrom, Glen G; Nix, Paola; Davis, M Wayne; Jorgensen, Erik M

2008-01-11

Muscle contraction is normally mediated by the release of neurotransmitters from motor neurons. Here we demonstrate that protons can act as a direct transmitter from intestinal cells to stimulate muscle contraction. During the C. elegans defecation motor program the posterior body muscles contract even in the absence of neuronal inputs or vesicular neurotransmission. In this study, we demonstrate that the space between the intestine and the muscle is acidified just prior to muscle contraction and that the release of caged protons is sufficient to induce muscle contraction. PBO-4 is a putative Na+/H+ ion exchanger expressed on the basolateral membrane of the intestine, juxtaposed to the posterior body muscles. In pbo-4 mutants the extracellular space is not acidified and the muscles fail to contract. The pbo-5 and pbo-6 genes encode subunits of a "cys-loop" proton-gated cation channel required for muscles to respond to acidification. In heterologous expression assays the PBO receptor is half-maximally activated at a pH of 6.8. The identification of the mechanisms for release and reception of proton signals establishes a highly unusual mechanism for intercellular communication.

Effect of Npt2b deletion on intestinal and renal inorganic phosphate (Pi) handling.

PubMed

Ikuta, Kayo; Segawa, Hiroko; Sasaki, Shohei; Hanazaki, Ai; Fujii, Toru; Kushi, Aoi; Kawabata, Yuka; Kirino, Ruri; Sasaki, Sumire; Noguchi, Miwa; Kaneko, Ichiro; Tatsumi, Sawako; Ueda, Otoya; Wada, Naoko A; Tateishi, Hiromi; Kakefuda, Mami; Kawase, Yosuke; Ohtomo, Shuichi; Ichida, Yasuhiro; Maeda, Akira; Jishage, Kou-Ichi; Horiba, Naoshi; Miyamoto, Ken-Ichi

2018-06-01

Hyperphosphatemia is common in chronic kidney disease and is associated with morbidity and mortality. The intestinal Na + -dependent phosphate transporter Npt2b is thought to be an important molecular target for the prevention of hyperphosphatemia. The role of Npt2b in the net absorption of inorganic phosphate (Pi), however, is controversial. In the present study, we made tamoxifen-inducible Npt2b conditional knockout (CKO) mice to analyze systemic Pi metabolism, including intestinal Pi absorption. Although the Na + -dependent Pi transport in brush-border membrane vesicle uptake levels was significantly decreased in the distal intestine of Npt2b CKO mice compared with control mice, plasma Pi and fecal Pi excretion levels were not significantly different. Data obtained using the intestinal loop technique showed that Pi uptake in Npt2b CKO mice was not affected at a Pi concentration of 4 mM, which is considered the typical luminal Pi concentration after meals in mice. Claudin, which may be involved in paracellular pathways, as well as claudin-2, 12, and 15 protein levels were significantly decreased in the Npt2b CKO mice. Thus, Npt2b deficiency did not affect Pi absorption within the range of Pi concentrations that normally occurs after meals. These findings indicate that abnormal Pi metabolism may also be involved in tight junction molecules such as Cldns that are affected by Npt2b deficiency.

A single-molecule sequencing assay for the comprehensive profiling of T4 DNA ligase fidelity and bias during DNA end-joining.

PubMed

Potapov, Vladimir; Ong, Jennifer L; Langhorst, Bradley W; Bilotti, Katharina; Cahoon, Dan; Canton, Barry; Knight, Thomas F; Evans, Thomas C; Lohman, Gregory Js

2018-05-08

DNA ligases are key enzymes in molecular and synthetic biology that catalyze the joining of breaks in duplex DNA and the end-joining of DNA fragments. Ligation fidelity (discrimination against the ligation of substrates containing mismatched base pairs) and bias (preferential ligation of particular sequences over others) have been well-studied in the context of nick ligation. However, almost no data exist for fidelity and bias in end-joining ligation contexts. In this study, we applied Pacific Biosciences Single-Molecule Real-Time sequencing technology to directly sequence the products of a highly multiplexed ligation reaction. This method has been used to profile the ligation of all three-base 5'-overhangs by T4 DNA ligase under typical ligation conditions in a single experiment. We report the relative frequency of all ligation products with or without mismatches, the position-dependent frequency of each mismatch, and the surprising observation that 5'-TNA overhangs ligate extremely inefficiently compared to all other Watson-Crick pairings. The method can easily be extended to profile other ligases, end-types (e.g. blunt ends and overhangs of different lengths), and the effect of adjacent sequence on the ligation results. Further, the method has the potential to provide new insights into the thermodynamics of annealing and the kinetics of end-joining reactions.

Surgical ligation of patent ductus arteriosus in premature infants: trends and practice variation.

PubMed

Weinberg, Jacqueline G; Evans, Frank J; Burns, Kristin M; Pearson, Gail D; Kaltman, Jonathan R

2016-08-01

We sought to analyse the variation in the incidence of patent ductus arteriosus over three recent time points and characterise ductal ligation practices in preterm infants in the United States, adjusting for demographic and morbidity factors. Using the Kids' Inpatient Database from 2003, 2006, and 2009, we identified infants born at ⩽32 weeks of gestation with International Classification of Diseases, Ninth Revision diagnosis of patent ductus arteriosus and ligation code. We examined patient and hospital characteristics and identified patient and hospital variables associated with ligation. Of 182,610 preterm births, 30,714 discharges included a patent ductus arteriosus diagnosis. The rate of patent ductus arteriosus diagnosis increased from 14% in 2003 to 21% in 2009 (p<0.001). A total of 4181 ligations were performed, with an overall ligation rate of 14%. Ligation rate in infants born at ⩽28 weeks of gestation was 20% overall, increasing from 18% in 2003 to 21% in 2009 (p<0.001). The ligation rate varied by state (4-28%), and ligation was associated with earlier gestational age, associated diagnoses, hospital type, teaching hospital status, and region (p<0.001). The rates of patent ductus arteriosus diagnosis and ligation have increased in the recent years. Variation exists in the practice of patent ductus arteriosus ligation and is influenced by patient and non-patient factors.

Evaluation of in vivo and in vitro biological activity of a Vibrio cholerae 01 hemolysin.

PubMed

Arellano Galindo, José; Rodriquez Angeles, María Guadalupe; Guadarrama, Norma Valázquez; Esteban, Enrique Santos; Cerezo, Silvia Giono

2007-01-01

To evaluate the hemolysin effect by ileal loop model produced by Vibrio cholerae O1 strains, compared with the cellular lysis or cytotoxic activity (CA) observed in cell culture. We studied nine V. cholerae O1 strains, obtained during the Mexican outbreak of cholera (1990-1993), which had CA in Vero and CHO cells. Hemolysin was monitored with the hemolysis test. Titers of CA were calculated by CD50, and the association between CA and cholera toxin (CT) production was discarded by means of neutralization tests using an anti-CT polyclonal antibody. The CT production was measured with ELISA test. The LAL assay was performed in order to study relationships between the CA and bacterial lipopolysaccharide. Strains with CA were evaluated in rabbit and rat ileal loop models; hemorrhagic fluid was also measured. Tissues from ileal loop were included in paraffin to detect intestinal epithelial damage. The hemolysin CA was not neutralized with the anti-CT polyclonal antibody. However, the associated factor of CA was heat labile. CA in cell cultures was not related to the bacterial lipopolysaccharide. The ileal loop test exhibited the presence of hemorrhagic tissue with inflammation. The V. cholerae O1 strains isolated were able to secrete hemolysin which, in turn, caused CA in cell cultures and produced the hemorrhagic and inflammatory effects observed in the ileal loop of rabbit and rat models.

Intra- and intermolecular nonenzymatic ligations occur within transcripts derived from the peach latent mosaic viroid.

PubMed

Lafontaine, D; Beaudry, D; Marquis, P; Perreault, J P

1995-10-01

We report here the nonenzymatic self-ligation of transcripts corresponding to the peach latent mosaic viroid (PLMVd). This is the first description of this process with viroid sequences, although it has been reported to occur with human hepatitis delta virus RNA. Self-ligation occurs when the 5'-hydroxyl and the 2',3'-cyclic phosphate termini produced by the hammerhead self-cleavage of the viroid RNA are juxtaposed by the viroid rod-like structure, and a phosphodiester bond is formed between the two following hydrolysis of the cyclic phosphate. Unit-length transcripts undergo intramolecular folding, and their subsequent self-ligation produces circular molecules. The self-ligation observed in vitro may contribute to PLMVd circularization during rolling circle replication; however, this does not exclude the possibility that a host RNA ligase catalyzes the ligation steps in vivo. Like self-cleavage, self-ligation is probably an ancestral reaction, and the enzyme-catalyzed ligation most likely evolved from this primitive mechanism. Furthermore, the intermolecular self-ligation of annealed transcripts derived from PLMVd is demonstrated, suggesting a possible mechanism for sequence reassortment in viroids.

Early ligation of the dorsal pancreatic artery with a mesenteric approach reduces intraoperative blood loss during pancreatoduodenectomy.

PubMed

Iede, Kiyotsugu; Nakao, Akimasa; Oshima, Kenji; Suzuki, Ryota; Yamada, Hironori; Oshima, Yukiko; Kobayashi, Hironobu; Kimura, Yasunori

2018-05-10

Early ligation of the inferior pancreatoduodenal artery has been advocated to reduce blood loss during pancreatoduodenectomy. However, the impact of early ligation of the dorsal pancreatic artery (DPA) remains unclear. This study was performed to investigate the clinical implications of early ligation of the DPA. From October 2014 to April 2017, 34 consecutive patients underwent pancreatoduodenectomy using a mesenteric approach. The patients were divided into the early DPA ligation group (n = 15) and late DPA ligation group (n = 19). The clinical features were retrospectively compared between the two groups (H29-044). Preoperative multidetector row computed tomography and intraoperative findings revealed that the right branch of the DPA supplied the pancreatic head region in all cases. Intraoperative blood loss was significantly lower in the early than late ligation group (median, 609 ml [range, 94-1013 ml] vs. 764 ml [range, 367-1828 ml], respectively; P = 0.008]. Multivariable analysis revealed that early DPA ligation was independently associated with blood loss (P = 0.023). The DPAs arising from the superior mesenteric artery underwent early ligation at a significantly higher rate. Early ligation of the DPA during pancreaticoduodenectomy with a mesenteric approach could reduce intraoperative blood loss. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Modulating effect of polyethylene glycol on the intestinal transport and absorption of prednisolone, methylprednisolone and quinidine in rats by in-vitro and in-situ absorption studies.

PubMed

Shen, Qi; Li, Wenji; Lin, Yulian; Katsumi, Hidemasa; Okada, Naoki; Sakane, Toshiyasu; Fujita, Takuya; Yamamoto, Akira

2008-12-01

The effects of polyethylene glycol 20000 (PEG 20000) on the intestinal absorption of prednisolone, methylprednisolone and quinidine, three P-glycoprotein (P-gp) substrates, across the isolated rat intestinal membranes were examined by an in-vitro diffusion chamber system. The serosal-to-mucosal (secretory) transport of these P-gp substrates was greater than their mucosal-to-serosal (absorptive) transport, indicating that their net movement across the intestinal membranes was preferentially in the secretory direction. The polarized secretory transport of these drugs was remarkably diminished and their efflux ratios decreased in the presence of PEG 20000. In addition, PEG 20000 did not affect the transport of Lucifer yellow, a non-P-gp substrate. The intestinal membrane toxicity of PEG 20000 was evaluated by measuring the release of alkaline phosphatase (ALP) and protein from the intestinal membranes. The release of ALP and protein was enhanced in the presence of 20 mM sodium deoxycholate (NaDC), a positive control, while these biological parameters did not change in the presence of 0.1-5% (w/v) PEG 20000. These findings indicated that the intestinal membrane damage caused by PEG 20000 was not a main reason for the enhanced absorptive transport of these P-gp substrates in the presence of PEG 20000. Furthermore, the transepithelial electrical resistance (TEER) of rat jejunal membranes in the presence or absence of PEG 20000 was measured by a diffusion chamber method. PEG 20000 (0.1-5.0 % w/v) did not change the TEER values of the rat jejunal membranes, indicating that the increase in the absorptive transport of these P-gp substrates might not be due to the increased transport of these P-gp substrates via a paracellular pathway caused by PEG 20000. Finally, the effect of PEG 20000 on the intestinal absorption of quinidine was examined by an in-situ closed-loop method. The intestinal absorption of quinidine was significantly enhanced in the presence of 0.1-1.0% (w/v) PEG 20000. These findings suggest that PEG 20000 might be a useful excipient to improve the intestinal absorption of quinidine, which is mainly secreted by a P-gp-mediated efflux system in the intestine.

Guanylyl Cyclase C Hormone Axis at the Intersection of Obesity and Colorectal Cancer.

PubMed

Blomain, Erik S; Merlino, Dante J; Pattison, Amanda M; Snook, Adam E; Waldman, Scott A

2016-09-01

Obesity has emerged as a principal cause of mortality worldwide, reflecting comorbidities including cancer risk, particularly in colorectum. Although this relationship is established epidemiologically, molecular mechanisms linking colorectal cancer and obesity continue to be refined. Guanylyl cyclase C (GUCY2C), a membrane-bound guanylyl cyclase expressed in intestinal epithelial cells, binds the paracrine hormones guanylin and uroguanylin, inducing cGMP signaling in colorectum and small intestine, respectively. Guanylin is the most commonly lost gene product in sporadic colorectal cancer, and its universal loss early in transformation silences GUCY2C, a tumor suppressor, disrupting epithelial homeostasis underlying tumorigenesis. In small intestine, eating induces endocrine secretion of uroguanylin, the afferent limb of a novel gut-brain axis that activates hypothalamic GUCY2C-cGMP signaling mediating satiety opposing obesity. Recent studies revealed that diet-induced obesity suppressed guanylin and uroguanylin expression in mice and humans. Hormone loss reflects reversible calorie-induced endoplasmic reticulum stress and the associated unfolded protein response, rather than the endocrine, adipokine, or inflammatory milieu of obesity. Loss of intestinal uroguanylin secretion silences the hypothalamic GUCY2C endocrine axis, creating a feed-forward loop contributing to hyperphagia in obesity. Importantly, calorie-induced guanylin loss silences the GUCY2C-cGMP paracrine axis underlying obesity-induced epithelial dysfunction and colorectal tumorigenesis. Indeed, genetically enforced guanylin replacement eliminated diet-induced intestinal tumorigenesis in mice. Taken together, these observations suggest that GUCY2C hormone axes are at the intersection of obesity and colorectal cancer. Moreover, they suggest that hormone replacement that restores GUCY2C signaling may be a novel therapeutic paradigm to prevent both hyperphagia and intestinal tumorigenesis in obesity. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Guanylyl Cyclase C Hormone Axis at the Intersection of Obesity and Colorectal Cancer

PubMed Central

Blomain, Erik S.; Merlino, Dante J.; Pattison, Amanda M.; Snook, Adam E.

2016-01-01

Obesity has emerged as a principal cause of mortality worldwide, reflecting comorbidities including cancer risk, particularly in colorectum. Although this relationship is established epidemiologically, molecular mechanisms linking colorectal cancer and obesity continue to be refined. Guanylyl cyclase C (GUCY2C), a membrane-bound guanylyl cyclase expressed in intestinal epithelial cells, binds the paracrine hormones guanylin and uroguanylin, inducing cGMP signaling in colorectum and small intestine, respectively. Guanylin is the most commonly lost gene product in sporadic colorectal cancer, and its universal loss early in transformation silences GUCY2C, a tumor suppressor, disrupting epithelial homeostasis underlying tumorigenesis. In small intestine, eating induces endocrine secretion of uroguanylin, the afferent limb of a novel gut-brain axis that activates hypothalamic GUCY2C-cGMP signaling mediating satiety opposing obesity. Recent studies revealed that diet-induced obesity suppressed guanylin and uroguanylin expression in mice and humans. Hormone loss reflects reversible calorie-induced endoplasmic reticulum stress and the associated unfolded protein response, rather than the endocrine, adipokine, or inflammatory milieu of obesity. Loss of intestinal uroguanylin secretion silences the hypothalamic GUCY2C endocrine axis, creating a feed-forward loop contributing to hyperphagia in obesity. Importantly, calorie-induced guanylin loss silences the GUCY2C-cGMP paracrine axis underlying obesity-induced epithelial dysfunction and colorectal tumorigenesis. Indeed, genetically enforced guanylin replacement eliminated diet-induced intestinal tumorigenesis in mice. Taken together, these observations suggest that GUCY2C hormone axes are at the intersection of obesity and colorectal cancer. Moreover, they suggest that hormone replacement that restores GUCY2C signaling may be a novel therapeutic paradigm to prevent both hyperphagia and intestinal tumorigenesis in obesity. PMID:27251363

Intestinal Permeability of β-Lapachone and Its Cyclodextrin Complexes and Physical Mixtures.

PubMed

Mangas-Sanjuan, Victor; Gutiérrez-Nieto, Jorge; Echezarreta-López, Magdalena; González-Álvarez, Isabel; González-Álvarez, Marta; Casabó, Vicente-Germán; Bermejo, Marival; Landin, Mariana

2016-12-01

β-Lapachone (βLAP) is a promising, poorly soluble, antitumoral drug. βLAP combination with cyclodextrins (CDs) improves its solubility and dissolution but there is not enough information about the impact of cyclodextrins on βLAP intestinal permeability. The objectives of this work were to characterize βLAP intestinal permeability and to elucidate cyclodextrins effect on the dissolution properties and on the intestinal permeability. The final goal was to evaluate CDs influence on the oral absorption of βLAP. Binary systems (physical mixtures and inclusion complexes) including βLAP and CDs (β-cyclodextrin: βCD, random-methyl-β-cyclodextrin: RMβCD and sulfobutylether-β-cyclodextrin: SBEβCD) have been prepared and analysed by differential scanning calorimetry. βLAP (and its combinations with CDs) absorption rate coefficients and effective permeability values have been determined in vitro in MDCK or MDCK-Mdr1 monolayers and in situ in rat by a closed loop perfusion technique. DSC results confirmed the formation of the inclusion complexes. βLAP-CDs inclusion complexes improve drug solubility and dissolution rate in comparison with physical mixtures. βLAP presented a high permeability value which can provide complete oral absorption. Its oral absorption is limited by its low solubility and dissolution rate. Cyclodextrin (both as physical mixtures and inclusion complexes) showed a positive effect on the intestinal permeability of βLAP. Complexation with CDs does not reduce βLAP intestinal permeability in spite of the potential negative effect of the reduction in free fraction of the drug. The use of RMβCD or SBEβCD inclusion complexes could benefit βLAP oral absorption by enhancing its solubility, dissolution rate and permeability.

[Self-ligating edgewise brackets. An overview].

PubMed

Katsaros, C; Dijkman, J F

2003-01-01

During the last years both the manufactures and the orthodontists seem to show an increased interest in self-ligating brackets. This paper aims to present the history of self-ligating systems, to describe the three mostly used bracketsystems and to review the relevant literature. It seems from the existing data that self-ligating brackets have certain advantages over conventionally ligated brackets. However, the data are still thin and a high need for well designed clinical trials exist.

The effect from different numbers of segmental arteries ligation to the spinal cord in the clinical practice of posterior vertebral column resection correction.

PubMed

Zhao, Zhi; Xie, Jingming; Wang, Yingsong; Bi, Ni; Li, Tao; Zhang, Ying; Shi, Zhiyue

2017-07-01

In using posterior vertebral column resection (PVCR) to treat severe kyphoscoliosis, it is unavoidable to ligate and cut off several segmental arteries (SAs) of the spinal cord for exposure and hemostasis, but which would raise the neurological risks. The aim of this study is to explore the changes of intraoperative spinal cord monitoring (IOM) following ligating different numbers of SAs in PVCR. Twenty-one consecutive patients with severe kyphoscoliosis were included and treated by PVCR correction. In operation, according to ligate different numbers of SAs, the IOM changes were recorded, respectively. Examinations of the covariance between different numbers of SAs ligations and IOM changes were performed to reveal the effect to the spinal cord by SAs ligations. In all the 21 cases, averaging 1.9 pairs of SAs were ligated. With the increased numbers of ligations, SSEP amplitudes and latencies were changed more obviously: from 1 to 3 pairs ligations, the mean decreased percentages of amplitudes were from 53.20 to 78.15%, the mean increased percentages of latency were from 1.23 to 1.40%, and the mean durations of decreased SSEP amplitudes were from 3.23 to 5.2 min; but without abnormal MEP changes. None occurred postoperative or delayed neurological deficit. Correlation analysis identified significant correlations between the number of SAs ligation and decreased percentage of SSEP amplitude (r = 0.945, P < 0.0001), and between the number of SAs being ligated and the duration of SSEP change (r = 0.945, P = 0.0002). Following the increased number of SAs ligation, the amplitude of SSEP is decreased more obviously with a much longer duration of recovery and the risk to spinal cord will be increased greatly. In the PVCR correction on the basis of spinal shortening, the numbers of SAs ligations should be as less as possible for neurological safety.

Waardenburg syndrome presenting with constipation since birth.

PubMed

Gupta, R; Sharma, S B; Mathur, P; Agrawal, L D

2014-12-01

Shah-Waardenburg syndrome is Waardenburg syndrome associated with Hirschsprung's disease. A 10-day-old full-term male neonate of Waardenburg syndrome presented with constipation since birth along with features of small bowel obstruction. Exploratory laparotomy revealed distended proximal jejunal and ileal loops along with microcolon; an ileostomy was performed. Postoperatively patient developed sepsis and died. Histopathology confirmed total colonic aganglionosis. Suspect familial Shah-Waardenburg syndrome in a neonate of Waardenburg syndrome presenting with constipation since birth or intestinal obstruction.

Epithelial cell kinase-B61: an autocrine loop modulating intestinal epithelial migration and barrier function.

PubMed

Rosenberg, I M; Göke, M; Kanai, M; Reinecker, H C; Podolsky, D K

1997-10-01

Epithelial cell kinase (Eck) is a member of a large family of receptor tyrosine kinases whose functions remain largely unknown. Expression and regulation of Eck and its cognate ligand B61 were analyzed in the human colonic adenocarcinoma cell line Caco-2. Immunocytochemical staining demonstrated coexpression of Eck and B61 in the same cells, suggestive of an autocrine loop. Eck levels were maximal in preconfluent cells. In contrast, B61 levels were barely detectable in preconfluent cells and increased progressively after the cells reached confluence. Caco-2 cells cultured in the presence of added B61 showed a significant reduction in the levels of dipeptidyl peptidase and sucrase-isomaltase mRNA, markers of Caco-2 cell differentiation. Cytokines interleukin-1beta (IL-1beta), basic fibroblast growth factor, IL-2, epidermal growth factor, and transforming growth factor-beta modulated steady-state levels of Eck and B61 mRNA and regulated Eck activation as assessed by tyrosine phosphorylation. Functionally, stimulation of Eck by B61 resulted in increased proliferation, enhanced barrier function, and enhanced restitution of injured epithelial monolayers. These results suggest that the Eck-B61 interaction, a target of regulatory peptides, plays a role in intestinal epithelial cell development, migration, and barrier function, contributing to homeostasis and preservation of continuity of the epithelial barrier.

Assessment of inflammatory activity in Crohn's disease by means of dynamic contrast-enhanced MRI.

PubMed

Pupillo, V A; Di Cesare, E; Frieri, G; Limbucci, N; Tanga, M; Masciocchi, C

2007-09-01

Our aim was to perform a dynamic study of contrast enhancement of the intestinal wall in patients with Crohn's disease to quantitatively assess local inflammatory activity. We studied a population of 50 patients with histologically proven Crohn's disease. Magnetic resonance imaging (MRI) was performed using a 1.5-T magnet with a phased-array coil and acquisition of T2-weighted single-shot fast spin echo (SSFSE) half Fourier sequences before intravenous administration of gadolinium, and T1-weighted fast spoiled gradient (FSPGR) fat-saturated sequences before and after contrast administration. Before the examination, patents received oral polyethylene glycol (PEG) (1,000 ml for adults; 10 ml/Kg of body weight for children). Regions of interest (ROI) were placed on the normal and diseased intestinal wall to assess signal intensity and rate of increase in contrast enhancement over time. Data were compared with the Crohn's Disease Activity Index (CDAI). The diseased bowel wall showed early and intense uptake of contrast that increases over time until a plateau is reached. In patients in the remission phase after treatment, signal intensity was only slightly higher in diseased bowel loops than in healthy loops. There was a significant correlation between the peak of contrast uptake and CDAI. Dynamic MRI is a good technique for quantifying local inflammatory activity of bowel wall in patients with Crohn's disease.

[Comparison of root resorption between self-ligating and conventional brackets using cone-beam CT].

PubMed

Liu, Yun; Guo, Hong-ming

2016-04-01

To analyze the differences of root resorption between passive self-ligating and conventional brackets, and to determine the relationship between passive self-ligating brackets and root resorption. Fifty patients were randomly divided into 2 groups using passive self-ligating brackets or conventional straight wire brackets (0.022 system), respectively. Cone-beam CT was taken before and after treatment. The amount of external apical root resorption of maxillary incisors was measured on CBCT images. Student's t test was performed to analyze the differences of root apical resorption between the 2 groups with SPSS17.0 software package. No significant difference(P> 0.05) in root resorption of maxillary incisors was found between passive self-ligating brackets and conventional brackets. Passive self-ligating brackets and conventional brackets can cause root resorption, but the difference was not significant. Passive self-ligating brackets do not induce more root resorption.

Microvillus-Specific Protein Tyrosine Phosphatase SAP-1 Plays a Role in Regulating the Intestinal Paracellular Transport of Macromolecules.

PubMed

Mori, Shingo; Kamei, Noriyasu; Murata, Yoji; Takayama, Kozo; Matozaki, Takashi; Takeda-Morishita, Mariko

2017-09-01

The stomach cancer-associated protein tyrosine phosphatase 1 (SAP-1) is a receptor-type protein tyrosine phosphatase that is specifically expressed on the apical membrane of the intestinal epithelium. SAP-1 is known to maintain the balance of phosphorylation of proteins together with protein kinases; however, its biological function and impact on pharmacokinetics in the intestine remain unclear. The present study, therefore, aimed at clarifying the relationship between SAP-1 and the intestinal absorption behaviors of typical transporter substrates and macromolecules. The endogenous levels of glucose and total cholesterol in the blood were similar between wild-type and SAP-1-deficient mice (Sap1 -/- ), suggesting no contribution of SAP-1 to biogenic influx. Moreover, in vitro transport study with everted ileal sacs demonstrated that there was no difference in the absorption of breast cancer resistance protein, P-glycoprotein, and peptide transporter substrates between both mice. However, absorptive clearance of macromolecular model dextrans (FD-4 and FD-10) in Sap1 -/- mice was significantly higher than that in wild-type mice, and this was confirmed by the trend of increased FD-4 absorption from colonic loops of Sap1 -/- mice. Therefore, the results of this study suggest the partial contribution of SAP-1 to the regulated transport of hydrophilic macromolecules through paracellular tight junctions. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

One-Pot/Sequential Native Chemical Ligation Using Photocaged Crypto-thioester.

PubMed

Aihara, Keisuke; Yamaoka, Kosuke; Naruse, Naoto; Inokuma, Tsubasa; Shigenaga, Akira; Otaka, Akira

2016-02-05

A practical and efficient methodology for the chemical synthesis of peptides/proteins using a one-pot/sequential ligation is described. It features the use of photocleavable S-protection on an N-sulfanylethylaniline moiety. Removal of the S-protecting ligated materials under UV irradiation provides a readily usable mixture for subsequent native chemical ligation.

Chemical Synthesis of Circular Proteins*

PubMed Central

Tam, James P.; Wong, Clarence T. T.

2012-01-01

Circular proteins, once thought to be rare, are now commonly found in plants. Their chemical synthesis, once thought to be difficult, is now readily achievable. The enabling methodology is largely due to the advances in entropic chemical ligation to overcome the entropy barrier in coupling the N- and C-terminal ends of large peptide segments for either intermolecular ligation or intramolecular ligation in end-to-end cyclization. Key elements of an entropic chemical ligation consist of a chemoselective capture step merging the N and C termini as a covalently linked O/S-ester intermediate to permit the subsequent step of an intramolecular O/S-N acyl shift to form an amide. Many ligation methods exploit the supernucleophilicity of a thiol side chain at the N terminus for the capture reaction, which makes cysteine-rich peptides ideal candidates for the entropy-driven macrocyclization. Advances in desulfurization and modification of the thiol-containing amino acids at the ligation sites to other amino acids add extra dimensions to the entropy-driven ligation methods. This minireview describes recent advances of entropy-driven ligation to prepare circular proteins with or without a cysteinyl side chain. PMID:22700959

A mass spectrometry-based multiplex SNP genotyping by utilizing allele-specific ligation and strand displacement amplification.

PubMed

Park, Jung Hun; Jang, Hyowon; Jung, Yun Kyung; Jung, Ye Lim; Shin, Inkyung; Cho, Dae-Yeon; Park, Hyun Gyu

2017-05-15

We herein describe a new mass spectrometry-based method for multiplex SNP genotyping by utilizing allele-specific ligation and strand displacement amplification (SDA) reaction. In this method, allele-specific ligation is first performed to discriminate base sequence variations at the SNP site within the PCR-amplified target DNA. The primary ligation probe is extended by a universal primer annealing site while the secondary ligation probe has base sequences as an overhang with a nicking enzyme recognition site and complementary mass marker sequence. The ligation probe pairs are ligated by DNA ligase only at specific allele in the target DNA and the resulting ligated product serves as a template to promote the SDA reaction using a universal primer. This process isothermally amplifies short DNA fragments, called mass markers, to be analyzed by mass spectrometry. By varying the sizes of the mass markers, we successfully demonstrated the multiplex SNP genotyping capability of this method by reliably identifying several BRCA mutations in a multiplex manner with mass spectrometry. Copyright © 2016 Elsevier B.V. All rights reserved.

Torque expression in self-ligating orthodontic brackets and conventionally ligated brackets: A systematic review

PubMed Central

Al-Thomali, Yousef; Mohamed, Roshan-Noor; Basha, Sakeenabi

2017-01-01

Background To evaluate the torque expression of self ligating (SL) orthodontic brackets and conventionally ligated brackets and the torque expression in active and passive SL brackets. Material and Methods Our systematic search included MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus, and key journals and review articles; the date of the last search was April 4th 2016. We graded the methodological quality of the studies by means of the Quality Assessment Tool for Quantitative Studies, developed for the Effective Public Health Practice Project (EPHPP). Results In total, 87 studies were identified for screening, and 9 studies were eligible. The quality assessment rated one of the study as being of strong quality, 7 (77.78%) of these studies as being of moderate quality. Three out of 7 studies which compared SL and conventionally ligated brackets showed, conventionally ligated brackets with highest torque expression compared to SL brackets. Badawi showed active SL brackets with highest torque expression compared to passive SL brackets. Major and Brauchli showed no significant differences in torque expression of active and passive SL brackets. Conclusions Conventionally ligated brackets presented with highest torque expression compared to SL brackets. Minor difference was recorded in a torque expression of active and passive SL brackets. Key words:Systematic review, self ligation, torque expression, conventional ligation. PMID:28149476

Torque expression in self-ligating orthodontic brackets and conventionally ligated brackets: A systematic review.

PubMed

Al-Thomali, Yousef; Mohamed, Roshan-Noor; Basha, Sakeenabi

2017-01-01

To evaluate the torque expression of self ligating (SL) orthodontic brackets and conventionally ligated brackets and the torque expression in active and passive SL brackets. Our systematic search included MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus, and key journals and review articles; the date of the last search was April 4th 2016. We graded the methodological quality of the studies by means of the Quality Assessment Tool for Quantitative Studies, developed for the Effective Public Health Practice Project (EPHPP). In total, 87 studies were identified for screening, and 9 studies were eligible. The quality assessment rated one of the study as being of strong quality, 7 (77.78%) of these studies as being of moderate quality. Three out of 7 studies which compared SL and conventionally ligated brackets showed, conventionally ligated brackets with highest torque expression compared to SL brackets. Badawi showed active SL brackets with highest torque expression compared to passive SL brackets. Major and Brauchli showed no significant differences in torque expression of active and passive SL brackets. Conventionally ligated brackets presented with highest torque expression compared to SL brackets. Minor difference was recorded in a torque expression of active and passive SL brackets. Key words: Systematic review, self ligation, torque expression, conventional ligation.

Initial experience with laparoscopic inferior epigastric vessel ligation for delayed transverse rectus abdominus musculocutaneous flap breast reconstruction.

PubMed

Trus, Thadeus L; Collins, E Dale; Demas, Christopher; Kerrigan, Carolyn

2007-04-01

Transverse rectus abdominus musculocutaneous (TRAM) flap breast reconstruction provides excellent cosmetic results. Pedicle flap viability is greatly enhanced by prereconstruction inferior epigastric vessel ligation, which encourages collateral arterial flow (delayed TRAM). We report our initial experience with laparoscopic inferior epigastric vessel ligation. Prospective case series. Tertiary academic center. Female patients with breast cancer who chose pedicle TRAM reconstruction. Vessel ligations were performed 7 to 14 days prior to reconstruction. Abdominal access was achieved with a 3-mm umbilical trocar. A 5-mm trocar was placed lateral to the rectus sheath in the right lower quadrant. Five-millimeter Teflon clips were used to ligate the vessels near their origin. Complications of surgery and subsequent flap viability. From January 2001 to July 2006, 130 patients had laparoscopic inferior epigastric vessel ligation, of whom 123 patients had bilateral ligation. Additional procedures in conjunction with vessel ligation were performed in 38 patients (sentinel node biopsy [27], bilateral oophorectomy [7], liver biopsy [2], breast biopsy [1], and Nissen fundoplication [1]). Median operative time for those patients undergoing ligation only was 32.6 minutes (range, 14-121 minutes). The inferior epigastric vessels were not identified in 2 patients. Metastatic breast cancer involving the liver was found in 1 patient. There were no conversions or complications. Subsequent TRAM flap viability was excellent in most cases, with 1 complete flap necrosis in a high-risk, morbidly obese patient. Laparoscopic inferior epigastric vessel ligation for delayed TRAM flap breast reconstruction is a safe, effective procedure.

Comparison of a New High-Frequency Electric Welding System for Intestinal Closure with Hand-Sewn In Vivo Pig Model.

PubMed

Han, Shuai; Cai, Zhai; Ning, Xuanjing; He, Linyun; Chen, Jun; Huang, Zonghai; Zhou, Huabin; Huang, Dequn; Zhang, Pusheng; Li, Zhou

2015-08-01

Various surgical small intestinal anastomosis methods are in current use, but improvements are always desired. Thus, we compared the feasibility, effectiveness, and safety of a new high-frequency electric welding (HFEW) system for sealing the small bowel versus a hand-sewn in vivo pig model. The 96 bowel segments of three pigs were randomized to be sutured either by the HFEW-300 PATONMED device (E.O. Paton Electric Welding Institute of the National Academy of Sciences of Ukraine, Kiev, Ukraine) or hand-sewn, and mucosa-to-mucosa fusions were subjected in vivo testing in the pigs. Bursting pressures, suture time, thermal damage, and the temperature of sealed ends were measured. Segments that had been treated with a hand-sutured ligature or double-sealed with HFEW were compared. Burst pressure was significantly higher in the hand-sutured group than in the HFEW group (136.2 mm Hg versus 75.8 mm Hg, P<.01). All 48 pig small bowels closed by the HFEW-300 generator showed a success rate of 100.0%. The closing time in the HFEW group was significantly shorter (P<.01). The pathological changes of the closed ends were mainly presented as acute thermal- and pressure-induced injuries. Outcomes of the current in vivo study suggest that HFEW is an effective and safe method for ligation of the small bowel in pigs.

Comparison of frictional resistance of esthetic and semi-esthetic self-ligating brackets

PubMed Central

Kannan, M. S.; Murali, R. V.; Kishorekumar, S.; Gnanashanmugam, K.; Jayanth, V.

2015-01-01

Aim: The frictional resistance encountered during sliding mechanics has been well established in the orthodontic literature, and it consists of complex interactions between the bracket, archwire, and method of ligation the claim of reduced friction with self-ligating brackets is often cited as a primary advantage over conventional brackets. This study was done to compare and evaluate the frictional forces generated between fully esthetic brackets and semi-aesthetic self-ligating brackets, which are of passive form and SEM (scanning electron microscope) study of the Brackets after Frictional evaluation. Materials and Methods: Two types of self-ligating esthetic brackets, Damon clear (Ormco) made of fully ceramic and Opal (Ultradent Products, USA) and, Two types of self-ligating semi-esthetic brackets, Clarity SL (3M Unitek) and Damon 3 (Ormco) both of which are made of ceramic with metal slot. Arch wires with different dimensions and quality 17 × 25, 19 × 25 Titanium Molybdenum Alloy (TMA) and 17 × 25, 19 × 25 stainless steel that came from plain strands of wire were used for frictional comparison test. The brackets used in this study had 0.022 × 0.028 inch slot. Results: The statistical tests showed significantly smaller amount of kinetic frictional forces is generated by Damon 3 (semi-esthetic self-ligating brackets). For each wire used, Damon 3 displayed significantly lower frictional forces (P ≤ 0.05) than any of the self-ligating system, followed by Opal (fully esthetic self-ligating brackets) which generated smaller amount of frictional forces but relatively on the higher side when compared with Damon 3. Damon clear (fully esthetic self-ligating brackets) generated the maximum amount of kinetic forces with all types of wire dimensions and properties when compared to the other three types of self-ligating system. Clarity SL (semi-esthetic self-ligating brackets) generated smaller amount of frictional forces when compared with Damon clear and relatively higher amount of frictional forces when compared to Opal and Damon 3 PMID:26015687

Comparison of frictional resistance of esthetic and semi-esthetic self-ligating brackets.

PubMed

Kannan, M S; Murali, R V; Kishorekumar, S; Gnanashanmugam, K; Jayanth, V

2015-04-01

The frictional resistance encountered during sliding mechanics has been well established in the orthodontic literature, and it consists of complex interactions between the bracket, archwire, and method of ligation the claim of reduced friction with self-ligating brackets is often cited as a primary advantage over conventional brackets. This study was done to compare and evaluate the frictional forces generated between fully esthetic brackets and semi-aesthetic self-ligating brackets, which are of passive form and SEM (scanning electron microscope) study of the Brackets after Frictional evaluation. Two types of self-ligating esthetic brackets, Damon clear (Ormco) made of fully ceramic and Opal (Ultradent Products, USA) and, Two types of self-ligating semi-esthetic brackets, Clarity SL (3M Unitek) and Damon 3 (Ormco) both of which are made of ceramic with metal slot. Arch wires with different dimensions and quality 17 × 25, 19 × 25 Titanium Molybdenum Alloy (TMA) and 17 × 25, 19 × 25 stainless steel that came from plain strands of wire were used for frictional comparison test. The brackets used in this study had 0.022 × 0.028 inch slot. The statistical tests showed significantly smaller amount of kinetic frictional forces is generated by Damon 3 (semi-esthetic self-ligating brackets). For each wire used, Damon 3 displayed significantly lower frictional forces (P ≤ 0.05) than any of the self-ligating system, followed by Opal (fully esthetic self-ligating brackets) which generated smaller amount of frictional forces but relatively on the higher side when compared with Damon 3. Damon clear (fully esthetic self-ligating brackets) generated the maximum amount of kinetic forces with all types of wire dimensions and properties when compared to the other three types of self-ligating system. Clarity SL (semi-esthetic self-ligating brackets) generated smaller amount of frictional forces when compared with Damon clear and relatively higher amount of frictional forces when compared to Opal and Damon 3.

Recursive Directional Ligation Approach for Cloning Recombinant Spider Silks.

PubMed

Dinjaski, Nina; Huang, Wenwen; Kaplan, David L

2018-01-01

Recent advances in genetic engineering have provided a route to produce various types of recombinant spider silks. Different cloning strategies have been applied to achieve this goal (e.g., concatemerization, step-by-step ligation, recursive directional ligation). Here we describe recursive directional ligation as an approach that allows for facile modularity and control over the size of the genetic cassettes. This approach is based on sequential ligation of genetic cassettes (monomers) where the junctions between them are formed without interrupting key gene sequences with additional base pairs.

Report of a Case and Review of Literature of Internal Hernia through Peritoneal Defect in Pouch of Douglas: A Rare Occurrence.

PubMed

Muthukumar, Vamseedharan; Venugopal, Sarveswaran; Subramaniam, Surees Kumar

2017-01-01

Intestinal obstruction attributable to internal hernia as a cause is a rare phenomenon with a reported incidence of 0.6%-5.8%. Internal hernias ensuing as a result of defect in the pouch of Douglas is extremely rare with only six such cases reported so far in the literature. We present a case of 74-year-old posthysterectomy status female who presented with features of intestinal obstruction. Intraoperatively, the site of obstruction was found to be a rent in the peritoneum of the pouch of Douglas through which a loop of ileum was found herniating. The viability of the bowel was confirmed, and the defect was closed. The postoperative course was uneventful. This report presents an extremely rare type of internal hernia caused by defect in the pouch of Douglas and review of the literature so far available.

Repeat laparotomy for the treatment of septic peritonitis in a Bornean orangutan (Pongo pygmaeus pygmaeus).

PubMed

Pollock, Patrick J; Doyle, Ronan; Tobin, Emma; Davison, Kate; Bainbridge, John

2008-09-01

A 9-yr-old female Bornean orangutan (Pongo pygmaeus pygmaeus) presented with a 48-hr history of depression, lethargy, anorexia, and mucoid discharge from the rectum. Clinical, radiographic, and ultrasonographic examination demonstrated the presence of multiple distended loops of intestine, intestinal adhesions, and free gas within the abdomen. During exploratory laparotomy, fibrinopurulent diffuse peritonitis as a result of a ruptured intrapelvic abscess with associated large bowel adhesions was evident. The abdomen was thoroughly lavaged, necrotic debris and abscess wall removed, and fibrinous adhesions disrupted. The orangutan was kept sedated for 48 hr to allow for intensive care. Six months later, when the orangutan presented with similar clinical signs, ultrasonographic examination demonstrated the presence of a pelvic abscess. The previous procedure was repeated with the addition of a hysterectomy. This report is the first documentation of long-term management following surgical intervention for internal abdominal abscessation and septic peritonitis in a great ape.

Strangulating intestinal obstructions in four captive elephants (Elephas maximus and Loxodonta africana).

PubMed

Wiedner, Ellen B; Peddie, James; Peddie, Linda Reeve; Abou-Madi, Noha; Kollias, George V; Doyle, Charles; Lindsay, William A; Isaza, Ramiro; Terrell, Scott; Lynch, Tim M; Johnson, Kari; Johnson, Gary; Sammut, Charlie; Daft, Barbara; Uzal, Francisco

2012-03-01

Three captive-born (5-day-old, 8-day-old, and 4-yr-old) Asian elephants (Elephas maximus) and one captive-born 22-yr-old African elephant (Loxodonta africana) from three private elephant facilities and one zoo in the United States presented with depression, anorexia, and tachycardia as well as gastrointestinal signs of disease including abdominal distention, decreased borborygmi, tenesmus, hematochezia, or diarrhea. All elephants showed some evidence of discomfort including agitation, vocalization, or postural changes. One animal had abnormal rectal findings. Nonmotile bowel loops were seen on transabdominal ultrasound in another case. Duration of signs ranged from 6 to 36 hr. All elephants received analgesics and were given oral or rectal fluids. Other treatments included warm-water enemas or walking. One elephant underwent exploratory celiotomy. Three animals died, and the elephant taken to surgery was euthanized prior to anesthetic recovery. At necropsy, all animals had severe, strangulating intestinal lesions.

HIV-1 evades virus-specific IgG2 and IgA class switching by targeting systemic and intestinal B cells via long-range intercellular conduits

PubMed Central

Xu, Weifeng; Santini, Paul A.; Sullivan, John S.; He, Bing; Shan, Meimei; Ball, Susan C.; Dyer, Wayne B.; Ketas, Thomas J.; Chadburn, Amy; Cohen-Gould, Leona; Knowles, Daniel M.; Chiu, April; Sanders, Rogier W.; Chen, Kang; Cerutti, Andrea

2009-01-01

Contact-dependent communication between immune cells generates protection, but also facilitates viral spread. We found that macrophages formed long-range actin-propelled conduits in response to negative factor (Nef), a human immunodeficiency virus type-1 (HIV-1) protein with immunosuppressive functions. Conduits attenuated immunoglobulin G2 (IgG2) and IgA class switching in systemic and intestinal lymphoid follicles by shuttling Nef from infected macrophages to B cells through a guanine exchange factor-dependent pathway involving the amino-terminal anchor, central core and carboxy-terminal flexible loop of Nef. By showing stronger virus-specific IgG2 and IgA responses in patients harboring Nef-deficient virions, our data suggest that HIV-1 exploits intercellular highways as a “Trojan horse” to deliver Nef to B cells and evade humoral immunity systemically and at mucosal sites of entry. PMID:19648924

An easier method for performing a pancreaticojejunostomy for the soft pancreas using a fast-absorbable suture

PubMed Central

Hakamada, Kenichi; Narumi, Shunji; Toyoki, Yoshikazu; Nara, Masaki; Ishido, Kenosuke; Miura, Takuya; Kubo, Norihito; Sasaki, Mutsuo

2008-01-01

AIM: To clarify the usefulness of a new method for performing a pancreaticojejunostomy by using a fast-absorbable suture material irradiated polyglactin 910, and a temporary stent tube for a narrow pancreatic duct with a soft pancreatic texture. METHODS: Among 63 consecutive patients with soft pancreas undergoing a pancreaticoduodenectomy from 2003 to 2006, 35 patients were treated with a new reconstructive method. Briefly, after the pancreatic transaction, a stent tube was inserted into the lumen of the pancreatic duct and ligated with it by a fast-absorbable suture. Another tip of the stent tube was introduced into the intestinal lumen at the jejunal limb, where a purse-string suture was made by another fast-absorbable suture to roughly fix the tube. The pancreaticojejunostomy was completed by ligating two fast-absorbable sutures to approximate the ductal end and the jejunal mucosa, and by adding a rough anastomosis between the pancreatic parenchyma and the seromuscular layer of the jejunum. The initial surgical results with this method were retrospectively compared with those of the 28 patients treated with conventional duct-to-mucosa anastomosis. RESULTS: The incidences of postoperative morbidity including pancreatic fistula were comparable between the two groups (new; 3%-17% vs conventional; 7%-14% according to the definitions). There was no mortality and re-admission. Late complications were also rarely seen. CONCLUSION: A pancreaticojejunostomy using an irradiated polyglactin 910 suture material and a temporary stent is easy to perform and is feasible even in cases with a narrow pancreatic duct and a normal soft pancreas. PMID:18286692

Biowaiver or Bioequivalence: Ambiguity in Sildenafil Citrate BCS Classification.

PubMed

Miranda, Claudia; Pérez-Rodríguez, Zenia; Hernández-Armengol, Rosario; Quiñones-García, Yaidel; Betancourt-Purón, Tania; Cabrera-Pérez, Miguel Ángel

2018-05-01

The aim of the present study is to contribute to the scientific characterization of sildenafil citrate according to the Biopharmaceutics Classification System, following the World Health Organization (WHO) guidelines for biowaivers. The solubility and intestinal permeability data of sildenafil citrate were collected from literature; however, the experimental solubility studies are inconclusive and its "high permeability" suggests an API in the borderline of BCS Class I and Class II. The pH-solubility profile was determined using the saturation shake-flask method over the pH range of 1.2-6.8 at a temperature of 37 °C in aqueous media. The intestinal permeability was determined in rat by a closed-loop in situ perfusion method (the Doluisio technique). The solubility of sildenafil citrate is pH-dependent and at pH 6.8 the dose/solubility ratio obtained does not meet the WHO criteria for "high solubility." The high permeability values obtained by in situ intestinal perfusion in rat reinforce the published permeability data for sildenafil citrate. The experimental results obtained and the data available in the literature suggest that sildenafil citrate is clearly a Class II of BCS, according to the current biopharmaceutics classification system and WHO guidance.

[Comparison of band ligation with sclerotherapy for the treatment of bleeding esophageal varices].

PubMed

Ríos, Eddy; Sierralta, Armando; Abarzúa, Marigraciela; Bastías, Joaquín; Barra, María Inés

2012-06-01

Endoscopic band ligation is the treatment of choice for bleeding esophageal varices. However it is not clear if this procedure is associated with less early and late mortality than sclerotherapy. To assess rates of re-bleeding and mortality in cohorts of patients with bleeding esophageal varices treated with endoscopic injection or band ligation. Analysis of medical records and endoscopy reports of two cohorts of patients with bleeding esophageal varices, treated between 1990 and 2010. Of these, 54 patients were treated with sclerotherapy and 90 patients with band ligation. A third cohort of 116 patients that did not require endoscopic treatment, was included. The mean analyzed follow up period was 2.5 years (range 1-16). Collection of data was retrospective for patients treated with sclerotherapy and prospective for patients treated with band ligation. Rates of re-bleeding and medium term mortality were assessed. During the month ensuing the first endoscopic treatment, re-bleeding was recorded in 39 and 72% of patients treated with band ligation and sclerotherapy, respectively (p < 0.01). The relative risk of bleeding after band ligation was 0.53 (95% confidence limits 0.390.73). Death rates until the end of follow up were 20 and 48% among patients with treated with band ligation and sclerotherapy, respectively (p < 0.01), with a relative risk of dying for patients subjected to band ligation of 0.41 (95% confidence limits 0.25-0.68). Band ligation was associated with lower rates of re-bleeding and mortality in these cohorts of patients.

Second Generation TQ-Ligation for Cell Organelle Imaging.

PubMed

Zhang, Xiaoyun; Dong, Ting; Li, Qiang; Liu, Xiaohui; Li, Lin; Chen, She; Lei, Xiaoguang

2015-07-17

Bioorthogonal ligations play a crucial role in labeling diverse types of biomolecules in living systems. Herein, we describe a novel class of ortho-quinolinone quinone methide (oQQM) precursors that show a faster kinetic rate in the "click cycloaddition" with thio-vinyl ether (TV) than the first generation TQ-ligation in both chemical and biological settings. We further demonstrate that the second generation TQ-ligation is also orthogonal to the widely used strain-promoted azide-alkyne cycloaddition (SPAAC) both in vitro and in vivo, revealing that these two types of bioorthogonal ligations could be used as an ideal reaction pair for the simultaneous tracking of multiple elements within a single system. Remarkably, the second generation TQ-ligation and SPAAC are effective for selective and simultaneous imaging of two different cell organelles in live cells.

Rubber band ligation and infrared photocoagulation for the outpatient treatment of hemorrhoidal disease.

PubMed

Ricci, Maurício Pichler; Matos, Délcio; Saad, Sarhan Sydney

2008-01-01

To compare the results of rubber band ligation and infrared photocoagulation for the treatment of hemorrhoidal disease through the analysis of the incidence of complications after each treatment and respective success rate. Forty-eight patients with first, second or third degree hemorrhoidal disease were randomized to receive treatment with either rubber band ligation (n=23) or infrared photocoagulation (n=25). Each patient was assessed at 1 week and 4 week intervals after treatment. We compared the incidence of complications and efficiency of each treatment modality and Qui-square, Fisher's Exact Test and Student's t Test were used to statistical analysis. Bleeding occured in eight (34,7%) patients treated with rubber band ligation and in four (16,0%) after infrared photocoagulation (p=0,243). Thirteen (52,0%) patients felt pain during infrared photocoagulation and 9 (39,1%) after rubber band ligation (p=0,546). After rubber band ligation, 14 (60,8%) required medication for pain relief. One patient (4,0%) required medication after infrared photocoagulation (p<0,001). Three (13,0%) patients treated with rubber band ligator and 1 (4,0%) treated with infrared photocoagulation had symptomatic mucosal ulcers. Perianal dermatitis occured in two (8,0%) patients treated with infrared photocoagulation and one patient (4,3%) was observed to have prolapsed thrombosed piles after rubber band ligation. One month after treatment, 17 of 23 patients treated with rubber band ligation (73,9%) and 18 of 25 patients treated with infrared photocoagulation were asymptomatic. Rubber band ligation treated bleeding and prolapse in 90,0% and 82,4% respectively. Infrared photocoagulation treats bleeding and prolapse in 93,7% and 87,5% respectively. Those differences are not significant. Rubber band ligation causes significantly more pain than infrared photocoagulation during the first week after the procedures and their success rate are not different after four weeks of treatment.

Elastomeric-ligated vs self-ligating appliances: a pilot study examining microbial colonization and white spot lesion formation after 1 year of orthodontic treatment.

PubMed

Buck, Tyson; Pellegrini, Peter; Sauerwein, Rebecca; Leo, Michael C; Covell, David A; Maier, Tom; Machida, Curtis A

2011-01-01

To (1) evaluate the use of adenosine triphosphate (ATP)-driven bioluminescence for quantification of total plaque bacteria in orthodontic patients, (2) compare plaque bacteria amounts at the bracket-tooth interface with use of elastomeric-ligated and self-ligating brackets after 1 year of orthodontic treatment, and (3) analyze formation of white spot lesions by photographic evaluation and laser-light fluorescence (DIAGNOdent). Thirteen subjects had fixed orthodontic appliances placed where lateral incisors were bonded with either elastomeric-ligated or self-ligating brackets. Plaque bacteria were collected from incisor surfaces after 1 year and quantified using plating methods and ATP-driven bioluminescence. White spot lesions were evaluated by photographic and DIAGNOdent determinations. A 2 x 2 x 2 mixed-design ANOVA was conducted to determine differences in plaque retention between elastomeric-ligated and self-ligating brackets. ATP-driven bioluminescence values correlated to numbers of total plaque bacteria (r = 0.80). However, unlike findings published in the original pilot study, which described increased plaque retention with elastomeric-ligated brackets at 5 weeks postbonding, there were no significant differences in bacterial numbers or ATP-driven bioluminescence values surrounding the elastomeric-ligated vs self-ligating brackets after 1 year of orthodontic treatment. Based on photographic and DIAGNOdent determinations, white spot lesions were found relatively equally on teeth bonded with either bracket type. DIAGNOdent measurements were found to have moderate sensitivity (0.71) and good specificity (0.88) when compared to white spot lesions determined using photographic evaluation. ATP-driven bioluminescence can be used as an accurate assessment of total plaque bacteria in orthodontic patients. After 1 year of orthodontic treatment for patients in this pilot study, there appeared to be no differences in retention of plaque bacteria or white spot lesions comparing the bracket types. The use of DIAGNOdent has some limitations, but may prove to be useful to monitor white spot lesions longitudinally.

Oral rice-based vaccine induces passive and active immunity against enterotoxigenic E. coli-mediated diarrhea in pigs.

PubMed

Takeyama, Natsumi; Yuki, Yoshikazu; Tokuhara, Daisuke; Oroku, Kazuki; Mejima, Mio; Kurokawa, Shiho; Kuroda, Masaharu; Kodama, Toshiaki; Nagai, Shinya; Ueda, Susumu; Kiyono, Hiroshi

2015-09-22

Enterotoxigenic Escherichia coli (ETEC) causes severe diarrhea in both neonatal and weaned pigs. Because the cholera toxin B subunit (CTB) has a high level of amino acid identity to the ETEC heat-labile toxin (LT) B-subunit (LTB), we selected MucoRice-CTB as a vaccine candidate against ETEC-induced pig diarrhea. When pregnant sows were orally immunized with MucoRice-CTB, increased amounts of antigen-specific IgG and IgA were produced in their sera. CTB-specific IgG was secreted in the colostrum and transferred passively to the sera of suckling piglets. IgA antibodies in the colostrum and milk remained high with a booster dose after farrowing. Additionally, when weaned minipigs were orally immunized with MucoRice-CTB, production of CTB-specific intestinal SIgA, as well as systemic IgG and IgA, was induced. To evaluate the cross-protective effect of MucoRice-CTB against ETEC diarrhea, intestinal loop assay with ETEC was conducted. The fluid volume accumulated in the loops of minipigs immunized with MucoRice-CTB was significantly lower than that in control minipigs, indicating that MucoRice-CTB-induced cross-reactive immunity could protect weaned pigs from diarrhea caused by ETEC. MucoRice-CTB could be a candidate oral vaccine for inducing both passive and active immunity to protect both suckling and weaned piglets from ETEC diarrhea. Copyright © 2015 Elsevier Ltd. All rights reserved.

Precise Sequential DNA Ligation on A Solid Substrate: Solid-Based Rapid Sequential Ligation of Multiple DNA Molecules

PubMed Central

Takita, Eiji; Kohda, Katsunori; Tomatsu, Hajime; Hanano, Shigeru; Moriya, Kanami; Hosouchi, Tsutomu; Sakurai, Nozomu; Suzuki, Hideyuki; Shinmyo, Atsuhiko; Shibata, Daisuke

2013-01-01

Ligation, the joining of DNA fragments, is a fundamental procedure in molecular cloning and is indispensable to the production of genetically modified organisms that can be used for basic research, the applied biosciences, or both. Given that many genes cooperate in various pathways, incorporating multiple gene cassettes in tandem in a transgenic DNA construct for the purpose of genetic modification is often necessary when generating organisms that produce multiple foreign gene products. Here, we describe a novel method, designated PRESSO (precise sequential DNA ligation on a solid substrate), for the tandem ligation of multiple DNA fragments. We amplified donor DNA fragments with non-palindromic ends, and ligated the fragment to acceptor DNA fragments on solid beads. After the final donor DNA fragments, which included vector sequences, were joined to the construct that contained the array of fragments, the ligation product (the construct) was thereby released from the beads via digestion with a rare-cut meganuclease; the freed linear construct was circularized via an intra-molecular ligation. PRESSO allowed us to rapidly and efficiently join multiple genes in an optimized order and orientation. This method can overcome many technical challenges in functional genomics during the post-sequencing generation. PMID:23897972

JNK1 induces hedgehog signaling from stellate cells to accelerate liver regeneration in mice.

PubMed

Langiewicz, Magda; Graf, Rolf; Humar, Bostjan; Clavien, Pierre A

2018-04-28

To improve outcomes of two-staged hepatectomies for large/multiple liver tumors, portal vein ligation (PVL) has been combined with parenchymal transection (associating liver partition and portal vein ligation for staged hepatectomy [coined ALPPS]) to greatly accelerate liver regeneration. In a novel ALPPS mouse model, we have reported paracrine Indian hedgehog (IHH) signaling from stellate cells as an early contributor to augmented regeneration. Here, we sought to identify upstream regulators of IHH. ALPPS in mice was compared against PVL and additional control surgeries. Potential IHH regulators were identified through in silico mining of transcriptomic data. c-Jun N-terminal kinase (JNK1 [Mapk8]) activity was reduced through SP600125 to evaluate its effects on IHH signaling. Recombinant IHH was injected after JNK1 diminution to substantiate their relationship during accelerated liver regeneration. Transcriptomic analysis linked Ihh to Mapk8. JNK1 upregulation after ALPPS was validated and preceded the IHH peak. On immunofluorescence, JNK1 and IHH co-localized in alpha-smooth muscle actin-positive non-parenchymal cells. Inhibition of JNK1 prior to ALPPS surgery reduced liver weight gain to PVL levels and was accompanied by downregulation of hepatocellular proliferation and the IHH-GLI1-CCND1 axis. In JNK1-inhibited mice, recombinant IHH restored ALPPS-like acceleration of regeneration and re-elevated JNK1 activity, suggesting the presence of a positive IHH-JNK1 feedback loop. JNK1-mediated induction of IHH paracrine signaling from hepatic stellate cells is essential for accelerated regeneration of parenchymal mass. The JNK1-IHH axis is a mechanism unique to ALPPS surgery and may point to therapeutic alternatives for patients with insufficient regenerative capacity. Associating liver partition and portal vein ligation for staged hepatectomy (so called ALPPS), is a new two-staged approach to hepatectomy, which induces an unprecedented acceleration of liver regeneration, enabling treatment of patients with liver tumors that would otherwise be considered unresectable. Herein, we demonstrate that JNK1-IHH signaling from stellate cells is a key mechanism underlying the regenerative acceleration that is induced by ALPPS. Copyright © 2018 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Improvement of absorption enhancing effects of n-dodecyl-beta-D-maltopyranoside by its colon-specific delivery using chitosan capsules.

PubMed

Fetih, Gihan; Lindberg, Sara; Itoh, Katsuhito; Okada, Naoki; Fujita, Takuya; Habib, Fawsia; Artersson, Per; Attia, Mohammed; Yamamoto, Akira

2005-04-11

In general, absorption enhancing effects of various absorption enhancers were greater in the large intestine than those in the small intestinal regions. Therefore, the effectiveness of absorption enhancers is expected to be remarkably observed, if these enhancers can be delivered to the large intestine with some poorly absorbable drugs after oral administration. In this study, therefore, we examined whether chitosan capsules were effective for the colon-specific delivery of a certain absorption enhancer and can improve the absorption enhancing action of the absorption enhancer after oral administration. 5(6)-Carboxyfluorescein (CF) was used as a model drug to investigate the site-dependent effectiveness of various absorption enhancers by an in situ closed loop method. Sodium glycocholate (NaGC), n-dodecyl-beta-d-maltopyranoside (LM), sodium salicylate (NaSal) and sodium caprate (NaCap) were used as models of absorption enhancers in this study. Overall, the absorption enhancing effects of these enhancers for intestinal absorption of CF were greater in the colon than those in the jejunum and the ileum. Especially, among these enhancers tested in this study, LM showed much greater absorption enhancing effect in the colon than in the jejunum and the ileum. Therefore, LM was selected as a model absorption enhancer to examine the effect of chitosan capsules on the absorption enhancing effect of LM. When CF and LM were orally administered to rats using chitosan capsules, the plasma concentration of CF was much higher than those in other dosage forms including solution and gelatin capsules. Therefore, chitosan capsules may be useful carriers for colon-specific delivery of LM, thereby increasing its absorption enhancing effect from the intestinal membranes.

Role of the ultrasonographic 'whirlpool sign' in intestinal volvulus: a systematic review and meta-analysis.

PubMed

Enyuma, Callistus O A; Adam, Ahmed; Aigbodion, Sunday J; McDowall, Jared; Gerber, Louis; Buchanan, Sean; Laher, Abdullah E

2018-05-08

Intestinal volvulus is a potentially life-threatening condition that occurs when loops of bowel twist around its supporting mesentery and associated vasculature. Clinicians often rely on various radiological investigations for prompt diagnosis to avoid complications such as bowel infarction. This review assesses the clinical reliability of the ultrasonographic whirlpool sign (WS) in the diagnosis of intestinal volvulus. In adherence with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-analyses) statement, a systematic search of BMJ Best Practice, Cochrane Database of Systematic Reviews, EMBASE, Google Scholar, PubMed, Scopus and Web of Science databases was performed (August 2017), using relevant search terms. Selected studies were ranked for quality and relevance using the CASP (Critical Appraisal Skills Program) tool. Sixteen articles (1640 participants) were assessed. The mean and median sample size was 102.5 (SD ± 192.23) and 28 (range 7-770), respectively. The WS was positive in 212 of 255 (83.1%) patients with intestinal volvulus. Meta-analysis of the studies that provided sufficient data resulted in a pooled sensitivity and specificity of 87.42% (95% confidence interval (CI): 81.05-92.25) and 98.63% (95% CI: 97.88-99.18), respectively, with an estimated summary effect of 5.28 (95% CI: 4.47-6.08, P < 0.001). There was negligible inter-study heterogeneity, which was suggested by an I 2 statistic of 0% (95% CI: 0.00-76.34) and a τ 2 parameter of 0 (95% CI: 0.00-5.35). Though the pooled sensitivity was less than ideal (87.42%), this review and meta-analysis nevertheless supports the reliability of the ultrasonographic WS as an acceptable indicator of intestinal volvulus. © 2018 Royal Australasian College of Surgeons.

Highly conserved type 1 pili promote enterotoxigenic E. coli pathogen-host interactions

PubMed Central

Rashu, Rasheduzzaman; Begum, Yasmin Ara; Ciorba, Matthew A.; Hultgren, Scott J.; Qadri, Firdausi

2017-01-01

Enterotoxigenic Escherichia coli (ETEC), defined by their elaboration of heat-labile (LT) and/or heat-stable (ST) enterotoxins, are a common cause of diarrheal illness in developing countries. Efficient delivery of these toxins requires ETEC to engage target host enterocytes. This engagement is accomplished using a variety of pathovar-specific and conserved E. coli adhesin molecules as well as plasmid encoded colonization factors. Some of these adhesins undergo significant transcriptional modulation as ETEC encounter intestinal epithelia, perhaps suggesting that they cooperatively facilitate interaction with the host. Among genes significantly upregulated on cell contact are those encoding type 1 pili. We therefore investigated the role played by these pili in facilitating ETEC adhesion, and toxin delivery to model intestinal epithelia. We demonstrate that type 1 pili, encoded in the E. coli core genome, play an essential role in ETEC virulence, acting in concert with plasmid-encoded pathovar specific colonization factor (CF) fimbriae to promote optimal bacterial adhesion to cultured intestinal epithelium (CIE) and to epithelial monolayers differentiated from human small intestinal stem cells. Type 1 pili are tipped with the FimH adhesin which recognizes mannose with stereochemical specificity. Thus, enhanced production of highly mannosylated proteins on intestinal epithelia promoted FimH-mediated ETEC adhesion, while conversely, interruption of FimH lectin-epithelial interactions with soluble mannose, anti-FimH antibodies or mutagenesis of fimH effectively blocked ETEC adhesion. Moreover, fimH mutants were significantly impaired in delivery of both heat-stable and heat-labile toxins to the target epithelial cells in vitro, and these mutants were substantially less virulent in rabbit ileal loop assays, a classical model of ETEC pathogenesis. Collectively, our data suggest that these highly conserved pili play an essential role in virulence of these diverse pathogens. PMID:28531220

Stimulation of synthesis and release of brain-derived neurotropic factor from intestinal smooth muscle cells by substance P and pituitary adenylate cyclase-activating peptide.

PubMed

Al-Qudah, M; Alkahtani, R; Akbarali, H I; Murthy, K S; Grider, J R

2015-08-01

Brain-derived neurotrophic factor (BDNF) is a neurotrophin present in the intestine where it participates in survival and growth of enteric neurons, augmentation of enteric circuits, and stimulation of intestinal peristalsis and propulsion. Previous studies largely focused on the role of neural and mucosal BDNF. The expression and release of BDNF from intestinal smooth muscle and the interaction with enteric neuropeptides has not been studied in gut. The expression and secretion of BDNF from smooth muscle cultured from the rabbit intestinal longitudinal muscle layer in response to substance P (SP) and pituitary adenylate cyclase-activating peptide (PACAP) was measured by western blot and enzyme-linked immunosorbent assay. BDNF mRNA was measured by reverse-transcription polymerase chain reaction. The expression of BNDF protein and mRNA was greater in smooth muscle cells (SMCs) from the longitudinal muscle than from circular muscle layer. PACAP and SP increased the expression of BDNF protein and mRNA in cultured longitudinal SMCs. PACAP and SP also stimulated the secretion of BDNF from cultured longitudinal SMCs. Chelation of intracellular calcium with BAPTA (1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid) prevented SP-induced increase in BDNF mRNA and protein expression and SP-induced secretion of BDNF. Neuropeptides known to be present in enteric neurons innervating the longitudinal layer increase the expression of BDNF mRNA and protein in SMCs and stimulate the release of BDNF. Considering the ability of BDNF to enhance smooth muscle contraction, this autocrine loop may partially explain the characteristic hypercontractility of longitudinal muscle in inflammatory bowel disease. © 2015 John Wiley & Sons Ltd.

Stimulation of Synthesis and Release of Brain-Derived Neurotropic Factor (BDNF) from Intestinal Smooth Muscle Cells by Substance P and Pituitary Adenylate Cyclase-Activating Peptide (PACAP)

PubMed Central

Al-Qudah, M.; Alkahtani, R.; Akbarali, H.I.; Murthy, K.S.; Grider, J.R.

2015-01-01

Background Brain-derived neurotrophic factor (BDNF) is a neurotrophin present in the intestine where it participates in survival and growth of enteric neurons, augmentation of enteric circuits, and stimulation of intestinal peristalsis and propulsion. Previous studies largely focused on the role of neural and mucosal BDNF. The expression and release of BDNF from intestinal smooth muscle and the interaction with enteric neuropeptides has not been studied in gut. Methods The expression and secretion of BDNF from smooth muscle cultured from rabbit longitudinal intestinal muscle in response to substance P and pituitary adenylate cyclase activating peptide (PACAP) was measured by western blot and ELISA. BDNF mRNA was measured by rt-PCR. Key Results The expression of BNDF protein and mRNA was greater in smooth muscle cells from the longitudinal muscle than from circular muscle layer. PACAP and substance P increased the expression of BDNF protein and mRNA in cultured longitudinal smooth muscle cells. PACAP and substance P also stimulated the secretion of BDNF from cultured longitudinal smooth muscle cells. Chelation of intracellular calcium with BAPTA prevented substance P-induced increase in BDNF mRNA and protein expression as well as substance P-induced secretion of BDNF. Conclusions & Inferences Neuropeptides known to be present in enteric neurons innervating the longitudinal layer increase the expression of BDNF mRNA and protein in smooth muscle cells and stimulate the release of BDNF. Considering the ability of BDNF to enhance smooth muscle contraction, this autocrine loop may partially explain the characteristic hypercontractility of longitudinal muscle in inflammatory bowel disease. PMID:26088546

The Use of Low Molecular Weight Protamine Chemical Chimera to Enhance Monomeric Insulin Intestinal Absorption

PubMed Central

He, Huining; Sheng, Jianyong; David, Allan E.; Kwon, Young Min; Zhang, Jian; Huang, Yongzhuo; Wang, Jianxin; Yang, Victor C.

2013-01-01

Although oral delivery of insulin offers a number of unmatched advantages, it nevertheless is beset by the poor permeability of insulin molecules through the epithelial cell membranes of the intestinal mucosal layer. We previously reported the development of low molecular weight protamine (LMWP) as a nontoxic yet potent cell penetrating peptide, of which via covalent linkage was capable of translocating protein cargos through the membranes of almost all cell types. It is therefore hypothesized that LMWP could be practically employed as a safe and effective tool to deliver insulin across the intestinal mucosal membrane, thereby augmenting its absorption through the GI tract. However, formulating 1:1 monomeric insulin/LMWP conjugate presents a tall order of challenge, as the acidic insulin and basic LMWP would automatically form tight aggregates through electrostatic interactions. In this paper, we developed an innovative conjugation strategy to solve this problem, by using succinimidyl-[(N-maleimidopropionamido)-polyethyleneglycol] ester (NHS-PEG-MAL) as an intermediate cross-linker during the coupling process. Both SDS-PAGE and MALDI-TOF mass spectroscopy confirmed the formation of a homogeneous, monomeric (1:1 ratio) insulin/LMWP conjugate without encountering the conventional problem of substrate aggregation. Cell culture studies demonstrated that transport of the Insulin-PEG-LMWP conjugate across the intestinal mucosal monolayer was augmented by almost five folds compared to native insulin. Furthermore, results from the in situ loop absorption tests in rats showed that systemic pharmacological bioavailability of insulin was significantly enhanced after its conjugation with LMWP. Overall, the presented chemical conjugation with LMWP could offer a reliable and safe means to improve the intestinal permeability of therapeutic peptides/proteins, shedding light of the possibility for their effective oral delivery. PMID:23863452

Blood flow changes after unilateral carotid artery ligation monitored by optical coherence tomography

NASA Astrophysics Data System (ADS)

Ma, Yushu; Liang, Chengbo; Suo, Yanyan; Zhao, Yuqian; Wang, Yi; Xu, Tao; Wang, Ruikang; Ma, Zhenhe

2016-03-01

Unilateral carotid artery ligation which could induce adaptive improvement is a classic model that has been widely used to study pathology of ischemic disease. In those studies, blood flow is an important parameter to characterize the ischemia. Optical coherence tomography (OCT) is a powerful imaging modality which can provide depth resolved images in biological tissue with high spatial and temporal resolution. SPF rats was anesthetized with isoflurane and divided into two groups. In first group, bilateral carotid artery was surgically exposed, and then left carotid artery was ligated. Blood flow changes of the contralateral carotid artery was monitored using high speed spectral domain optical coherence tomography, including the absolute flow velocity and the flow volume. In the other group, skull window was opened at the ipsilateral cerebral cortex of ligation and blood supply of small artery was measured before and after the ligation. The measured results demonstrate the blood supply compensation process after unilateral carotid artery ligation. With the superiority of high resolution, OCT is an effective technology in monitoring results of carotid artery after ligation.

Realizing Serine/Threonine Ligation: Scope and Limitations and Mechanistic Implication Thereof

NASA Astrophysics Data System (ADS)

Wong, Clarence; Li, Tianlu; Lam, Hiu Yung; Zhang, Yinfeng; LI, Xuechen

2014-05-01

Serine/Threonine ligation (STL) has emerged as an alternative tool for protein chemical synthesis, bioconjugations as well as macrocyclization of peptides of various sizes. Owning to the high abundance of Ser/Thr residues in natural peptides and proteins, STL is expected to find a wide range of applications in chemical biology research. Herein, we have fully investigated the compatibility of the serine/threonine ligation strategy for X-Ser/Thr ligation sites, where X is any of the 20 naturally occurring amino acids. Our studies have shown that 17 amino acids are suitable for ligation, while Asp, Glu, and Lys are not compatible. Among the working 17 C-terminal amino acids, the retarded reaction resulted from the bulky β-branched amino acid (Thr, Val and Ile) is not seen under the current ligation condition. We have also investigated the chemoselectivity involving the amino group of the internal lysine which may compete with the N-terminal Ser/Thr for reaction with the C-terminal salicylaldehyde (SAL) ester aldehyde group. The result suggested that the free internal amino group does not adversely slow down the ligation rate.

Discovery of Specific Inhibitors for Intestinal E. coli   β-Glucuronidase through In Silico Virtual Screening

PubMed Central

Cheng, Ta-Chun; Cheng, Kai-Wen; Leu, Yu-Lin; Chuang, Chih-Hung; Huang, Chien-Chaio; Hsieh, Yuan-Chin; Chang, Long-Sen; Cheng, Tian-Lu

2015-01-01

Glucuronidation is a major metabolism process of detoxification for carcinogens, 4-(methylnitrosamino)-1-(3-pyridy)-1-butanone (NNK) and 1,2-dimethylhydrazine (DMH), of reactive oxygen species (ROS). However, intestinal E. coli    β-glucuronidase (eβG) has been considered pivotal to colorectal carcinogenesis. Specific inhibition of eβG may prevent reactivating the glucuronide-carcinogen and protect the intestine from ROS-mediated carcinogenesis. In order to develop specific eβG inhibitors, we found that 59 candidate compounds obtained from the initial virtual screening had high inhibition specificity against eβG but not human βG. In particular, we found that compounds 7145 and 4041 with naphthalenylidene-benzenesulfonamide (NYBS) are highly effective and selective to inhibit eβG activity. Compound 4041  (IC50 = 2.8 μM) shows a higher inhibiting ability than compound 7145  (IC50 = 31.6 μM) against eβG. Furthermore, the molecular docking analysis indicates that compound 4041 has two hydrophobic contacts to residues L361 and I363 in the bacterial loop, but 7145 has one contact to L361. Only compound 4041 can bind to key residue (E413) at active site of eβG via hydrogen-bonding interactions. These novel NYBS-based eβG specific inhibitors may provide as novel candidate compounds, which specifically inhibit eβG to reduce eβG-based carcinogenesis and intestinal injury. PMID:25839056

Discovery of specific inhibitors for intestinal E. coli  β-glucuronidase through in silico virtual screening.

PubMed

Cheng, Ta-Chun; Chuang, Kuo-Hsiang; Roffler, Steve R; Cheng, Kai-Wen; Leu, Yu-Lin; Chuang, Chih-Hung; Huang, Chien-Chaio; Kao, Chien-Han; Hsieh, Yuan-Chin; Chang, Long-Sen; Cheng, Tian-Lu; Chen, Chien-Shu

2015-01-01

Glucuronidation is a major metabolism process of detoxification for carcinogens, 4-(methylnitrosamino)-1-(3-pyridy)-1-butanone (NNK) and 1,2-dimethylhydrazine (DMH), of reactive oxygen species (ROS). However, intestinal E. coli   β-glucuronidase (eβG) has been considered pivotal to colorectal carcinogenesis. Specific inhibition of eβG may prevent reactivating the glucuronide-carcinogen and protect the intestine from ROS-mediated carcinogenesis. In order to develop specific eβG inhibitors, we found that 59 candidate compounds obtained from the initial virtual screening had high inhibition specificity against eβG but not human βG. In particular, we found that compounds 7145 and 4041 with naphthalenylidene-benzenesulfonamide (NYBS) are highly effective and selective to inhibit eβG activity. Compound 4041  (IC50 = 2.8 μM) shows a higher inhibiting ability than compound 7145  (IC50 = 31.6 μM) against eβG. Furthermore, the molecular docking analysis indicates that compound 4041 has two hydrophobic contacts to residues L361 and I363 in the bacterial loop, but 7145 has one contact to L361. Only compound 4041 can bind to key residue (E413) at active site of eβG via hydrogen-bonding interactions. These novel NYBS-based eβG specific inhibitors may provide as novel candidate compounds, which specifically inhibit eβG to reduce eβG-based carcinogenesis and intestinal injury.

[Interintestinal anastomoses formation using permanent magnet in surgical treatment of children with intestinal stomas].

PubMed

Gatkin, E Ja; Razumovskij, A Ju; Korsunskij, A A; Konovalov, A K; Sergeev, A V; Vinogradov, A Ja; Sein, V A

2015-01-01

It was analyzed the results of treatment of 48 children aged from 1 month to 14 years. In these observations by the 6th - 7th days after doubleintestinalstoma formation magnetic dies with inductance from 300 to 360 mTl and energy force at least 255 kJ/m3 were introduced into lumen of afferent and efferent intestinal loops. Attractive or compression force between dies was 600 g, i.e. force per 1 cm2 was 200 g according to dies' surface 1.12.83.0 cm. Magnets are not only surgical instruments but also physiotherapeutic devices improving microcirculation and stimulating regeneration in the area of anastomosis. Interintestinal anastomosis has been completely formed for 5-7 days. Thereafter magnetic dies have been removed. Stool was normalized in 45 of 48 observations after surgery (1-3 times daily). Intestinal discharge from ileostomy reduced to minimal amount. In 2 patients irregular bowel movements was observed due to adhesive stenosis of interintestinal anastomosis. Magnetic dies can't be established in 1 case due to adhesive process. Hospital stay was from 10 to 25 days in 41 children. 7 patients were discharged for outpatient treatment later. All children were under observation for the period 2-4 months after discharge. Signs of hypotrophy including body weight deficit within 10% of age norm were diagnosed only in 3 children with prematurity degree I-II. Hereafter children were repeatedly hospitalized; intestinal stomas were surgically removed using conventional technique. Thus complete convalescence was obtained.

Small bowel obstruction caused by Anisakis and Meckel's diverticulum: a rare case.

PubMed

Carbotta, G; Laforgia, R; Milella, Michele; Sederino, M G; Minafra, M; Fortarezza, F; Piscitelli, D; Palasciano, N

2016-01-01

Anisakiasis is a parasitic infection caused by the ingestion of raw fish contaminated by larval nematodes of Anisakis species. Intestinal or extraintestinal manifestations are rated to > 4% and >1% respectively. A 61-year old patient was admitted to our General Surgical and Emergency Unit because of sudden abdominal pain, vomit and constipation. He had eaten raw fish 3 days before admission. Laboratory data showed high levels of WBC and PCR. CT scanning showed "dilation of jejunum and ileum loops, thickening of the terminal ileum and cecum and signs of inflammation of the intestinal wall and mesentery". The following emergency surgical procedure was performed: laparotomy with evidence of obstruction of the small bowels, a giant Meckel's diverticulum, resection of terminal ileum and cecum and ileocolonic anastomosis. At the microscopic examination, the intestinal wall appeared occupied by a transmural inflammatory infiltrate, mainly eosinophilic, edema and nematode larvae, referable to Anisakis, surrounded by necrotic-inflammatory material. Moreover, there was evidence of giant a Meckel's diverticulum. Normally, enteric anisakiasis exhibits leukocytosis with eosinophilia and high CRP levels. There are cases of successful medical treatment and other cases of endoscopic treatment avoiding surgical procedure. In our case, enteric Anisakias had not been taken into consideration at the moment of the operation and only histopathology could reveal Anisakis larvae inside the intestinal wall. Our surgical approach is considered in literature as the best one for this clinical presentation. Those patients need to be better studied and more attention should be paid to their history.

Obturator hernia: A diagnostic challenge.

PubMed

Kulkarni, Sanjeev R; Punamiya, Aditya R; Naniwadekar, Ramchandra G; Janugade, Hemant B; Chotai, Tejas D; Vimal Singh, T; Natchair, Arafath

2013-01-01

Obturator hernia is an extremely rare type of hernia with relatively high mortality and morbidity. Its early diagnosis is challenging since the signs and symptoms are non specific. Here in we present a case of 70 years old women who presented with complaints of intermittent colicky abdominal pain and vomiting. Plain radiograph of abdomen showed acute dilatation of stomach. Ultrasonography showed small bowel obstruction at the mid ileal level with evidence of coiled loops of ileum in pelvis. On exploration, Right Obstructed Obturator hernia was found. The obstructed Intestine was reduced and resected and the obturator foramen was closed with simple sutures. Postoperative period was uneventful. Obturator hernia is a rare pelvic hernia and poses a diagnostic challenge. Obturator hernia occurs when there is protrusion of intra-abdominal contents through the obturator foramen in the pelvis. The signs and symptoms are non specific and generally the diagnosis is made during exploration for the intestinal obstruction, one of the four cardinal features. Others are pain on the medial aspect of thigh called as Howship Rombergs sign, repeated attacks of Intestinal Obstruction and palpable mass on the medial aspect of thigh. Obturator hernia is a rare but significant cause of intestinal obstruction especially in emaciated elderly woman and a diagnostic challenge for the Doctors. CT scan is valuable to establish preoperative diagnosis. Surgery either open or laproscopic, is the only treatment. The need for the awareness is stressed and CT scan can be helpful. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Hi-C 2.0: An optimized Hi-C procedure for high-resolution genome-wide mapping of chromosome conformation.

PubMed

Belaghzal, Houda; Dekker, Job; Gibcus, Johan H

2017-07-01

Chromosome conformation capture-based methods such as Hi-C have become mainstream techniques for the study of the 3D organization of genomes. These methods convert chromatin interactions reflecting topological chromatin structures into digital information (counts of pair-wise interactions). Here, we describe an updated protocol for Hi-C (Hi-C 2.0) that integrates recent improvements into a single protocol for efficient and high-resolution capture of chromatin interactions. This protocol combines chromatin digestion and frequently cutting enzymes to obtain kilobase (kb) resolution. It also includes steps to reduce random ligation and the generation of uninformative molecules, such as unligated ends, to improve the amount of valid intra-chromosomal read pairs. This protocol allows for obtaining information on conformational structures such as compartment and topologically associating domains, as well as high-resolution conformational features such as DNA loops. Copyright © 2017 Elsevier Inc. All rights reserved.

Ligation site in proteins recognized in silico

PubMed Central

Brylinski, Michal; Konieczny, Leszek; Roterman, Irena

2006-01-01

Recognition of a ligation site in a protein molecule is important for identifying its biological activity. The model for in silico recognition of ligation sites in proteins is presented. The idealized hydrophobic core stabilizing protein structure is represented by a three-dimensional Gaussian function. The experimentally observed distribution of hydrophobicity compared with the theoretical distribution reveals differences. The area of high differences indicates the ligation site. Availability http://bioinformatics.cm-uj.krakow.pl/activesite PMID:17597871

Effects of fasting and refeeding on gene expression of slc15a1a, a gene encoding an oligopeptide transporter (PepT1), in the intestine of Mozambique tilapia.

PubMed

Orozco, Zenith Gaye A; Soma, Satoshi; Kaneko, Toyoji; Watanabe, Soichi

2017-01-01

The tissue distribution of slc15a1a, a gene that encodes an oligopeptide transporter, PepT1, and its response to fasting and refeeding were investigated in the intestinal epithelium of Mozambique tilapia for a better understanding of its role on nutrient absorption. The slc15a1a was predominantly expressed in the absorptive epithelia of the anterior part of the intestine, suggesting that digested oligopeptides are primarily absorbed in the anterior intestine. The response of slc15a1a to fasting was evaluated at 1, 2, 4, 7 and 14days after the last feeding. Fasting revealed a biphasic effect, where short-term fasting significantly upregulated slc15a1a expression and long-term fasting resulted in downregulation. The expression level continued to decrease and fell below the pre-fasted level from day 4 to 14. Proximal (the hepatic loop, HL) and distal parts (the proximal major coil, PMC) of the anterior intestine showed different magnitudes of responses to fasting; slc15a1a expression in the PMC showed greater upregulation and downregulation than that in the HL. Refeeding significantly stimulated slc15a1a expression at day 3, although the expression did not exceed the pre-fasted level. Observed responses of slc15a1a to fasting and refeeding suggest that the expression level of this gene can serve as a sensitive indicator of the changes that may occur in altering nutritional conditions. These findings contribute to a better understanding of the role of PepT1 in nutrition and of the complex mechanisms underlying the absorption of oligopeptides and amino acids in the intestine, and may lead to development of possible means to manipulate the absorption processes for the improvement of growth and other metabolic and physiological conditions in fish. Copyright © 2016. Published by Elsevier Inc.

Role of Tir and Intimin in the Virulence of Rabbit Enteropathogenic Escherichia coli Serotype O103:H2

PubMed Central

Marchès, Olivier; Nougayrède, Jean-Philippe; Boullier, Séverine; Mainil, Jacques; Charlier, Gérard; Raymond, Isabelle; Pohl, Pierre; Boury, Michèle; De Rycke, Jean; Milon, Alain; Oswald, Eric

2000-01-01

Attaching and effacing (A/E) rabbit enteropathogenic Escherichia coli (REPEC) strains belonging to serogroup O103 are an important cause of diarrhea in weaned rabbits. Like human EPEC strains, they possess the locus of enterocyte effacement clustering the genes involved in the formation of the A/E lesions. In addition, pathogenic REPEC O103 strains produce an Esp-dependent but Eae (intimin)-independent alteration of the host cell cytoskeleton characterized by the formation of focal adhesion complexes and the reorganization of the actin cytoskeleton into bundles of stress fibers. To investigate the role of intimin and its translocated coreceptor (Tir) in the pathogenicity of REPEC, we have used a newly constructed isogenic tir null mutant together with a previously described eae null mutant. When human HeLa epithelial cells were infected, the tir mutant was still able to induce the formation of stress fibers as previously reported for the eae null mutant. When the rabbit epithelial cell line RK13 was used, REPEC O103 produced a classical fluorescent actin staining (FAS) effect, whereas both the eae and tir mutants were FAS negative. In a rabbit ligated ileal loop model, neither mutant was able to induce A/E lesions. In contrast to the parental strain, which intimately adhered to the enterocytes and destroyed the brush border microvilli, bacteria of both mutants were clustered in the mucus without reaching and damaging the microvilli. The role of intimin and Tir was then analyzed in vivo by oral inoculation of weaned rabbits. Although both mutants were still present in the intestinal flora of the rabbits 3 weeks after oral inoculation, neither mutant strain induced any clinical signs or significant weight loss in the inoculated rabbits whereas the parental strain caused the death of 90% of the inoculated rabbits. Nevertheless, an inflammatory infiltrate was present in the lamina propria of the rabbits infected with both mutants, with an inflammatory response greater for the eae null mutant. In conclusion, we have confirmed the role of intimin in virulence, and we have shown, for the first time, that Tir is also a key factor in vivo for pathogenicity. PMID:10722617

Role of tir and intimin in the virulence of rabbit enteropathogenic Escherichia coli serotype O103:H2.

PubMed

Marchès, O; Nougayrède, J P; Boullier, S; Mainil, J; Charlier, G; Raymond, I; Pohl, P; Boury, M; De Rycke, J; Milon, A; Oswald, E

2000-04-01

Attaching and effacing (A/E) rabbit enteropathogenic Escherichia coli (REPEC) strains belonging to serogroup O103 are an important cause of diarrhea in weaned rabbits. Like human EPEC strains, they possess the locus of enterocyte effacement clustering the genes involved in the formation of the A/E lesions. In addition, pathogenic REPEC O103 strains produce an Esp-dependent but Eae (intimin)-independent alteration of the host cell cytoskeleton characterized by the formation of focal adhesion complexes and the reorganization of the actin cytoskeleton into bundles of stress fibers. To investigate the role of intimin and its translocated coreceptor (Tir) in the pathogenicity of REPEC, we have used a newly constructed isogenic tir null mutant together with a previously described eae null mutant. When human HeLa epithelial cells were infected, the tir mutant was still able to induce the formation of stress fibers as previously reported for the eae null mutant. When the rabbit epithelial cell line RK13 was used, REPEC O103 produced a classical fluorescent actin staining (FAS) effect, whereas both the eae and tir mutants were FAS negative. In a rabbit ligated ileal loop model, neither mutant was able to induce A/E lesions. In contrast to the parental strain, which intimately adhered to the enterocytes and destroyed the brush border microvilli, bacteria of both mutants were clustered in the mucus without reaching and damaging the microvilli. The role of intimin and Tir was then analyzed in vivo by oral inoculation of weaned rabbits. Although both mutants were still present in the intestinal flora of the rabbits 3 weeks after oral inoculation, neither mutant strain induced any clinical signs or significant weight loss in the inoculated rabbits whereas the parental strain caused the death of 90% of the inoculated rabbits. Nevertheless, an inflammatory infiltrate was present in the lamina propria of the rabbits infected with both mutants, with an inflammatory response greater for the eae null mutant. In conclusion, we have confirmed the role of intimin in virulence, and we have shown, for the first time, that Tir is also a key factor in vivo for pathogenicity.

Evaluation of Micro-organism in Ligated Metal and Self-ligating Brackets using Scanning Electron Microscopy: An In Vivo Study

PubMed Central

Sunil, P C; Michael, Tony; Raju, Aravind S; Paul, Renji K; Mamatha, J; Ebin, T M

2015-01-01

Background: The objective of the study was to determine the sites of plaque accumulation and to compare the plaque accumulated with metal and self-ligating orthodontic brackets in order to know which bracket type had a higher plaque retaining capacity. Materials and Methods: The study was done on 20 subjects who were scheduled for orthodontic treatment including extraction of four premolars and fixed orthodontic appliances. Mesh-backed edgewise metal brackets ligated with steel ligatures and self-ligating brackets were bonded to the premolars to be extracted using composite (Transbond XT, 3M). The subjects were told to continue their normal oral hygiene regimen. Teeth were extracted at 1, 2, and 3 weeks after bracket bonding. Plaque attached to the buccal surfaces was stained using plaque disclosing agent. The teeth were then immersed in fixative containing 4% formaldehyde and 1% glutaraldehyde in phosphate buffer for 24 h, followed by 0.1 M phosphate buffer for 12 h. The specimens were then mounted on aluminum stubs, and sputter coated with gold prior to Scanning electron microscopy examination. Results: The results showed that increased retention of plaque in metal brackets ligated with steel ligatures and comparatively less in self-ligating brackets at the base of the brackets. Conclusions: This study highlights that higher retention of plaque in metal brackets ligated with steel ligatures and comparatively less plaque retention in self-ligating brackets. Excess composite around the bracket base is the critical site of plaque accumulation associated with fixed appliances due to its rough surface texture. PMID:26229372

Evaluation of Micro-organism in Ligated Metal and Self-ligating Brackets using Scanning Electron Microscopy: An In Vivo Study.

PubMed

Sunil, P C; Michael, Tony; Raju, Aravind S; Paul, Renji K; Mamatha, J; Ebin, T M

2015-07-01

The objective of the study was to determine the sites of plaque accumulation and to compare the plaque accumulated with metal and self-ligating orthodontic brackets in order to know which bracket type had a higher plaque retaining capacity. The study was done on 20 subjects who were scheduled for orthodontic treatment including extraction of four premolars and fixed orthodontic appliances. Mesh-backed edgewise metal brackets ligated with steel ligatures and self-ligating brackets were bonded to the premolars to be extracted using composite (Transbond XT, 3M). The subjects were told to continue their normal oral hygiene regimen. Teeth were extracted at 1, 2, and 3 weeks after bracket bonding. Plaque attached to the buccal surfaces was stained using plaque disclosing agent. The teeth were then immersed in fixative containing 4% formaldehyde and 1% glutaraldehyde in phosphate buffer for 24 h, followed by 0.1 M phosphate buffer for 12 h. The specimens were then mounted on aluminum stubs, and sputter coated with gold prior to Scanning electron microscopy examination. The results showed that increased retention of plaque in metal brackets ligated with steel ligatures and comparatively less in self-ligating brackets at the base of the brackets. This study highlights that higher retention of plaque in metal brackets ligated with steel ligatures and comparatively less plaque retention in self-ligating brackets. Excess composite around the bracket base is the critical site of plaque accumulation associated with fixed appliances due to its rough surface texture.

Sleep-related changes in cardiovascular autonomic regulation in left coronary artery ligation rats: Neural mechanism facilitating arrhythmia after myocardial infarction.

PubMed

Lin, Wei-Lun; Lo, Li-Wei; Chen, Hau-Ruey; Lai, Chun-Ting; Yamada, Shinya; Liu, Shin-Huei; Chou, Yu-Hui; Chen, Shih-Ann; Fu, Yun-Ching; Kuo, Terry B J

2016-12-15

Autonomic imbalance with increased sympathetic and decreased parasympathetic activities is observed in patients after myocardial infarction (MI). We aimed to investigate sleep-related changed in autonomic regulation in left coronary artery (LCA) ligation rats. Wireless transmission of polysomnographic recording was performed in sham and LCA ligation male rats during normal daytime sleep with and without atenolol treatment. Spectral analyses of the electroencephalogram (EEG) and electromyogram (EMG) were evaluated to define active waking (AW), quiet and paradoxical sleeps (QS, PS). Cardiac autonomic activities were measured by analyzing the power spectrum of heart rate variability (HRV). EEG, EMG and HRV were recorded over 6h for consecutive 3days in all groups. In LCA ligation group, there were higher LF and LF/HF ratio on QS phase, but not AW and PS phases, compared to atenolol treated sham and LCA ligation groups, respectively. The HF component was not significantly changed on all groups in both sleep and awake phases. Sleep interruption was more frequent in LCA ligation rats compared to sham, and it was not found in LCA ligation with atenolol treatment group. Increased AW, PS and decreased QS time were noted in LCA ligation group, compared to sham and it was restored to baseline in LCA ligation with atenolol treatment group. Our results demonstrate significant sleep fragmentations with sympathetic hyperactivity during QS stages after MI, and atenolol could restore the autonomic dysfunction and sleep disturbance. The finding explains the cause of sleep-related fetal arrhythmia and sudden cardiac death after MI. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Structural analysis of a highly glycosylated and unliganded gp120-based antigen using mass spectrometry†

PubMed Central

Wang, Liwen; Qin, Yali; Ilchenko, Serguei; Bohon, Jen; Shi, Wuxian; Cho, Michael W.; Takamoto, Keiji; Chance, Mark R.

2010-01-01

Structural characterization of the HIV envelope protein gp120 is very important to provide an understanding of the protein's immunogenicity and it's binding to cell receptors. So far, crystallographic structure determination of gp120 with an intact V3 loop (in the absence of CD4 co-receptor or antibody) has not been achieved. The third variable region (V3) of the gp120 is immunodominant and contains glycosylation signatures that are essential for co-receptor binding and viral entry to T-cells. In this study, we characterized the structure of the outer domain of gp120 with an intact V3 loop (gp120-OD8) purified from Drosophila S2 cells utilizing mass spectrometry-based approaches. We mapped the glycosylation sites and calculated glycosylation occupancy of gp120-OD8; eleven sites from fifteen glycosylation motifs were determined as having high mannose or hybrid glycosylation structures. The specific glycan moieties of nine glycosylation sites from eight unique glycopeptides were determined by a combination of ECD and CID MS approaches. Hydroxyl radical-mediated protein footprinting coupled with mass spectrometry analysis was employed to provide detailed information on protein structure of gp120-OD8 by directly identifying accessible and hydroxyl radical-reactive side chain residues. Comparison of gp120-OD8 experimental footprinting data with a homology model derived from the ligated CD4/ gp120-OD8 crystal structure revealed a flexible V3 loop structure where the V3 tip may provide contacts with the rest of the protein while residues in the V3 base remain solvent accessible. In addition, the data illustrate interactions between specific sugar moieties and amino acid side chains potentially important to the gp120-OD8 structure. PMID:20825246

Efficient DNA ligation in DNA–RNA hybrid helices by Chlorella virus DNA ligase

PubMed Central

Lohman, Gregory J. S.; Zhang, Yinhua; Zhelkovsky, Alexander M.; Cantor, Eric J.; Evans, Thomas C.

2014-01-01

Single-stranded DNA molecules (ssDNA) annealed to an RNA splint are notoriously poor substrates for DNA ligases. Herein we report the unexpectedly efficient ligation of RNA-splinted DNA by Chlorella virus DNA ligase (PBCV-1 DNA ligase). PBCV-1 DNA ligase ligated ssDNA splinted by RNA with kcat ≈ 8 x 10−3 s−1 and KM < 1 nM at 25°C under conditions where T4 DNA ligase produced only 5′-adenylylated DNA with a 20-fold lower kcat and a KM ≈ 300 nM. The rate of ligation increased with addition of Mn2+, but was strongly inhibited by concentrations of NaCl >100 mM. Abortive adenylylation was suppressed at low ATP concentrations (<100 µM) and pH >8, leading to increased product yields. The ligation reaction was rapid for a broad range of substrate sequences, but was relatively slower for substrates with a 5′-phosphorylated dC or dG residue on the 3′ side of the ligation junction. Nevertheless, PBCV-1 DNA ligase ligated all sequences tested with 10-fold less enzyme and 15-fold shorter incubation times than required when using T4 DNA ligase. Furthermore, this ligase was used in a ligation-based detection assay system to show increased sensitivity over T4 DNA ligase in the specific detection of a target mRNA. PMID:24203707

Debris and friction of self-ligating and conventional orthodontic brackets after clinical use.

PubMed

Araújo, Raíssa Costa; Bichara, Lívia Monteiro; Araujo, Adriana Monteiro de; Normando, David

2015-07-01

To compare the degree of debris and friction of conventional and self-ligating orthodontic brackets before and after clinical use. Two sets of three conventional and self-ligating brackets were bonded from the first molar to the first premolar in eight individuals, for a total of 16 sets per type of brackets. A passive segment of 0.019 × 0.025-inch stainless steel archwire was inserted into each group of brackets. Frictional force and debris level were evaluated as received and after 8 weeks of intraoral exposure. Two-way analysis of variance and Wilcoxon signed-rank test were applied at P < .05. After the intraoral exposure, there was a significant increase of debris accumulation in both systems of brackets (P < .05). However, the self-ligating brackets showed a higher amount of debris compared with the conventional brackets. The frictional force in conventional brackets was significantly higher when compared with self-ligating brackets before clinical use (P < .001). Clinical exposure for 8 weeks provided a significant increase of friction (P < .001) on both systems. In the self-ligating system, the mean of friction increase was 0.21 N (191%), while 0.52 N (47.2%) was observed for the conventional system. Self-ligating and conventional brackets, when exposed to the intraoral environment, showed a significant increase in frictional force during the sliding mechanics. Debris accumulation was higher for the self-ligating system.

Pinhole castration: a novel minimally invasive technique for in situ spermatic cord ligation.

PubMed

Ponvijay, Kombairaju S

2007-01-01

To describe a minimally invasive technique for castration of bull calves by in situ ligation of the spermatic cord. Experimental study. Male calves (n=6) aged, 48-56 days. Calves were blocked by weight and then separated into 3 groups: (1) bilateral spermatic cord ligation; (2) unilateral-1 spermatic cord ligated; and (3) control-neither spermatic cord ligated. After local anesthesia, in situ spermatic cord ligation was achieved by restraining the cord laterally within the scrotal sac and passing suture through a hypodermic needle inserted caudal to cranial at the neck of the scrotum and adjacent the medial margin of the restrained spermatic cord. The needle was removed leaving the suture in place and the spermatic cord repositioned medially, then the needle was reinserted through the original holes and the suture passed back through the needle, which was withdrawn. The suture ends were tied ligating the spermatic cord, leaving the knot subcutaneously. Calves were monitored and testes removed after 30 days for gross and histologic examination. Castration was accomplished without postoperative complications. Spermatic cord ligation resulted in testis atrophy, and histologically, complete ischemic necrosis. This novel minimally invasive technique is a simple, alternative method for castration of bull calves. This method of castration is simply performed, without obvious skin wounds, and no postoperative care needed. The technique should be readily adaptable to other species.

A randomized prospective trial of the postoperative quality of life between laparoscopic uterine artery ligation and laparoscopy-assisted vaginal hysterectomy for the treatment of symptomatic uterine fibroids: clinical trial design

PubMed Central

Kim, Hee Seung; Kim, Jae Weon; Kim, Mi-Kyung; Chung, Hyun Hoon; Lee, Taek Sang; Jeon, Yong-Tark; Kim, Yong Beom; Jeon, Hye Won; Yun, Young Ho; Park, Noh Hyun; Song, Yong Sang; Kang, Soon-Beom

2009-01-01

Background Laparoscopy-assisted vaginal hysterectomy is one of the definite methods for the treatment of symptomatic uterine fibroids with lesser intraoperative bleeding and shorter hospitalization compared with abdominal hysterectomy. However, laparoscopy-assisted vaginal hysterectomy cannot preserve uterus and can show postoperative complications by the change of pelvic structure. Thus, laparoscopic uterine artery ligation has been introduced for relieving the symptoms caused by uterine fibroids in place of hysterectomy. The current study was designed to compare postoperative quality of life between laparoscopic uterine artery ligation and laparoscopy-assisted vaginal hysterectomy, and to evaluate the efficacy of laparoscopic uterine artery ligation which can treat symptomatic uterine fibroids with the preservation of uterus. Methods and design Patients enrolled the current study are randomized to laparoscopic uterine artery ligation or laparoscopy-assisted vaginal hysterectomy. The primary outcome is to compare postoperative quality of life between laparoscopic uterine artery ligation and laparoscopy-assisted vaginal hysterectomy using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire for Cancer patients version 3.0. Secondary outcomes are to evaluate the volume reduction of uterus, uterine fibroids and ovaries by the 2 treatments, to compare the improvement of subjective symptoms using 11-point symptom score and postoperative clinical outcomes between laparoscopic uterine artery ligation and laparoscopy-assisted vaginal hysterectomy, and to investigate the improvement of postoperative vaginal bleeding by laparoscopic uterine artery ligation. Discussion Among treatment methods for symptomatic uterine fibroids with the preservation of uterus, laparoscopic uterine artery ligation is expected to have the efficacy like uterine artery embolization, which appeared to be safe for routine use with symptomatic relief. The current study fully recruited in June 2008 and the results will be available in June 2009. If there is no difference of postoperative QOL between laparoscopic uterine artery ligation and laparoscopy-assisted vaginal hysterectomy for the treatment of symptomatic uterine fibroids, the comparison of quality of life between laparoscopic uterine artery ligation and uterine artery embolization will be also needed as a surgical treatment for preserving uterus. Trial registration Current Controlled Trials ISRCTN76790866 PMID:19178748

Hysteroscopic Tubal Sterilization

PubMed Central

McMartin, K

2013-01-01

Background Hysteroscopic tubal sterilization is a minimally invasive alternative to laparoscopic tubal ligation for women who want permanent contraception. The procedures involves non-surgical placement of permanent microinserts into both fallopian tubes. Patients must use alternative contraception for at least 3 months postprocedure until tubal occlusion is confirmed. Compared to tubal ligation, potential advantages of the hysteroscopic procedure are that it can be performed in 10 minutes in an office setting without the use of general or even local anesthesia. Objective The objective of this analysis was to determine the effectiveness and safety of hysteroscopic tubal sterilization compared with tubal ligation for permanent female sterilization. Data Sources A standard systematic literature search was conducted for studies published from January 1, 2008, until December 11, 2012. Review Methods Observational studies, randomized controlled trials (RCTs), systematic reviews and meta-analyses with 1 month or more of follow-up were examined. Outcomes included failure/pregnancy rates, adverse events, and patient satisfaction. Results No RCTs were identified. Two systematic reviews covered 22 observational studies of hysteroscopic sterilization. Only 1 (N = 93) of these 22 studies compared hysteroscopic sterilization to laparoscopic tubal ligation. Two other noncomparative case series not included in the systematic reviews were also identified. In the absence of comparative studies, data on tubal ligation were derived for this analysis from the CREST study, a large, multicentre, prospective, noncomparative observational study in the United States (GRADE low). Overall, hysteroscopic sterilization is associated with lower pregnancy rates and lower complication rates compared to tubal ligation. No deaths have been reported for hysteroscopic sterilization. Limitations A lack of long-term follow-up for hysteroscopic sterilization and a paucity of studies that directly compare the two procedures limit this assessment. In addition, optimal placement of the microinsert at the time of hysteroscopy varied among studies. Conclusions Hysteroscopic sterilization is associated with: lower pregnancy rates compared to tubal ligation (GRADE very low) lower complication rates compared to tubal ligation (GRADE very low) no significant improvement in patient satisfaction compared to tubal ligation (GRADE very low) Plain Language Summary Hysteroscopic tubal sterilization is a minimally invasive alternative to conventional tubal ligation for women who want a permanent method of contraception. Both approaches involve closing off the fallopian tubes, preventing the egg from moving down the tube and the sperm from reaching the egg. Tubal ligation is a surgical procedure to tie or seal the fallopian tubes, and it usually requires general anesthesia. In contrast, hysteroscopic tubal sterilization can be performed in 10 minutes in an office setting without general or even local anesthesia. A tiny device called a microinsert is inserted into each fallopian tube through the vagina, cervix, and uterus without surgery. An instrument called a hysteroscope allows the doctor to see inside the body for the procedure. Once the microinserts are in place, scar tissue forms around them and blocks the fallopian tubes. Health Quality Ontario conducted a review of the effectiveness and safety of hysteroscopic tubal sterilization compared to tubal ligation. This review indicates that hysteroscopic tubal sterilization is associated with: lower pregnancy rates compared to tubal ligation lower complication rates compared to tubal ligation no significant improvement in patient satisfaction compared to tubal ligation However, we found a number of limitations to the studies available on hysteroscopic tubal sterilization. Among other concerns, most studies did not include long-term follow-up and only 1 study directly compared hysteroscopic tubal sterilization to tubal ligation. PMID:24228084

Native chemical ligation at Asx-Cys, Glx-Cys: chemical synthesis and high-resolution X-ray structure of ShK toxin by racemic protein crystallography.

PubMed

Dang, Bobo; Kubota, Tomoya; Mandal, Kalyaneswar; Bezanilla, Francisco; Kent, Stephen B H

2013-08-14

We have re-examined the utility of native chemical ligation at -Gln/Glu-Cys- [Glx-Cys] and -Asn/Asp-Cys- [Asx-Cys] sites. Using the improved thioaryl catalyst 4-mercaptophenylacetic acid (MPAA), native chemical ligation could be performed at -Gln-Cys- and Asn-Cys- sites without side reactions. After optimization, ligation at a -Glu-Cys- site could also be used as a ligation site, with minimal levels of byproduct formation. However, -Asp-Cys- is not appropriate for use as a site for native chemical ligation because of formation of significant amounts of β-linked byproduct. The feasibility of native chemical ligation at -Gln-Cys- enabled a convergent total chemical synthesis of the enantiomeric forms of the ShK toxin protein molecule. The D-ShK protein molecule was ~50,000-fold less active in blocking the Kv1.3 channel than the L-ShK protein molecule. Racemic protein crystallography was used to obtain high-resolution X-ray diffraction data for ShK toxin. The structure was solved by direct methods and showed significant differences from the previously reported NMR structures in some regions of the ShK protein molecule.

A retrospective analysis of short and long term efficacy of RBL for hemorrhoids.

PubMed

Lu, L Y; Zhu, Y; Sun, Q

2013-10-01

Rubber band ligation is an effective treatment for hemorrhoids. A retrospective analysis was performed to evaluate its short and long-term efficacy. From 2000 to 2008, 254 outpatients with II- degree and 114 with III-degree hemorrhoids underwent rubber band ligation. Two or three hemorrhoids were ligated per session. Each haemorrhoid was ligated with two rubber bands through a ligator. All patients were visited after two months and followed up through a telephone after two and eleven years. Twenty-four or forty-eight hours post treatment, 41% of patients had mild-moderate pain. Four patients showed severe pain and required for haemorrhoidectomy within a few days. Only 2% of patients experienced self-limiting rectal bleeding after one week and 6% of patients had an additional ligation within two months. Two months later, 92% of II-degree patients and 76% of III-degree patients showed no residual symptoms. After two and eleven years, the history of 314 patients (85%) were obtained, of them, 70% was asymptomatic, 27% had some residual symptoms of occasional bleeding and prolapse, and 3% needed further surgery. Rubber band ligation is an efficient, cost-effective and simple outpatient procedure for the second and third degree hemorrhoids with minimal complications.

In vitro evaluation of resistance to sliding in self-ligating and conventional bracket systems during dental alignment.

PubMed

Cordasco, Giancarlo; Lo Giudice, Antonino; Militi, Angela; Nucera, Riccardo; Triolo, Giuseppe; Matarese, Giovanni

2012-08-01

To investigate the resistance to sliding (RS) in self-ligating and conventional ligation bracket systems at 5 different second-order bracket angulations by using low-stiffness alignment wires in a 3-bracket experimental model and to verify the performance of the main RS components in both systems when these wires are used. Interactive self-ligating brackets with closed and open slides were used for the self-ligating (SL) and conventional ligation (CL) groups, respectively; elastomeric ligatures (1 mm inner diameter) were used in the latter system. The alignment wire used was 0.014 inch heat-activated NiTi (austenitic finish temperature set at 36℃ by the manufacturer). A custom-made testing machine was used to measure frictional resistance. Tests were repeated 5 times at every angulation simulated. All data were analyzed statistically. The RS increased significantly with increasing angulation in both SL and CL groups (p < 0.0001). However, the RS values were significantly higher at every angulation (p < 0.0001) in the CL group. Despite the relevance of the binding phenomenon, ligation forces predominantly affect the RS when low-stiffness alignment wires are used.

In vitro evaluation of resistance to sliding in self-ligating and conventional bracket systems during dental alignment

PubMed Central

Cordasco, Giancarlo; Lo Giudice, Antonino; Militi, Angela; Nucera, Riccardo; Triolo, Giuseppe

2012-01-01

Objective To investigate the resistance to sliding (RS) in self-ligating and conventional ligation bracket systems at 5 different second-order bracket angulations by using low-stiffness alignment wires in a 3-bracket experimental model and to verify the performance of the main RS components in both systems when these wires are used. Methods Interactive self-ligating brackets with closed and open slides were used for the self-ligating (SL) and conventional ligation (CL) groups, respectively; elastomeric ligatures (1 mm inner diameter) were used in the latter system. The alignment wire used was 0.014 inch heat-activated NiTi (austenitic finish temperature set at 36℃ by the manufacturer). A custom-made testing machine was used to measure frictional resistance. Tests were repeated 5 times at every angulation simulated. All data were analyzed statistically. Results The RS increased significantly with increasing angulation in both SL and CL groups (p < 0.0001). However, the RS values were significantly higher at every angulation (p < 0.0001) in the CL group. Conclusions Despite the relevance of the binding phenomenon, ligation forces predominantly affect the RS when low-stiffness alignment wires are used. PMID:23112953

Investigation into the effects of stainless steel ligature ties on the mechanical characteristics of conventional and self-ligated brackets subjected to torque.

PubMed

Al Fakir, Hussam; Carey, Jason P; Melenka, Garrett W; Nobes, David S; Heo, Giseon; Major, Paul W

2014-09-01

Torque is applied to orthodontic brackets in order to alter the buccal-lingual angulation of a tooth. One factor that can affect torque is the ligation mode used to retain the archwire in the bracket slot. The objective of this study was to investigate the effects of stainless steel ligation on torque expression and bracket deformation. This study utilized 60 upper right central incisor Damon Q brackets and 60 Ormco Orthos Twin brackets. The brackets used in this study were subdivided into four groups: (1) Damon Q ligated with SS ligature; (2) Damon Q with the sliding bracket door; (3) Orthos Twin bracket ligated with SS wire; and (4) Orthos Twin ligated with elastic ties. All brackets were tested using an orthodontic torque simulating device that applied archwire rotation from 0° to 45°. All brackets ligated with stainless steel ties exhibited greater torque expression and less deformation than brackets without stainless steel ties. As well, Damon Q brackets exhibit less bracket deformation than Orthos Twin brackets. Stainless steel ties can reduce the amount of plastic deformation for both types of brackets used in this study. © 2014 British Orthodontic Society.

Formation of oligonucleotide-PNA-chimeras by template-directed ligation

NASA Technical Reports Server (NTRS)

Koppitz, M.; Nielsen, P. E.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

1998-01-01

DNA sequences have previously been reported to act as templates for the synthesis of PNA, and vice versa. A continuous evolutionary transition from an informational replicating system based on one polymer to a system based on the other would be facilitated if it were possible to form chimeras, that is molecules that contain monomers of both types. Here we show that ligation to form chimeras proceeds efficiently both on PNA and on DNA templates. The efficiency of ligation is primarily determined by the number of backbone bonds at the ligation site and the relative orientation of template and substrate strands. The most efficient reactions result in the formation of chimeras with ligation junctions resembling the structures of the backbones of PNA and DNA and with antiparallel alignment of both components of the chimera with the template, that is, ligations involving formation of 3'-phosphoramidate and 5'-ester bonds. However, double helices involving PNA are stable both with antiparallel and parallel orientation of the two strands. Ligation on PNA but not on DNA templates is, therefore, sometimes possible on templates with reversed orientation. The relevance of these findings to discussions of possible transitions between genetic systems is discussed.

Chemical Ligation of Folded Recombinant Proteins: Segmental Isotopic Labeling of Domains for NMR Studies

NASA Astrophysics Data System (ADS)

Xu, Rong; Ayers, Brenda; Cowburn, David; Muir, Tom W.

1999-01-01

A convenient in vitro chemical ligation strategy has been developed that allows folded recombinant proteins to be joined together. This strategy permits segmental, selective isotopic labeling of the product. The src homology type 3 and 2 domains (SH3 and SH2) of Abelson protein tyrosine kinase, which constitute the regulatory apparatus of the protein, were individually prepared in reactive forms that can be ligated together under normal protein-folding conditions to form a normal peptide bond at the ligation junction. This strategy was used to prepare NMR sample quantities of the Abelson protein tyrosine kinase-SH(32) domain pair, in which only one of the domains was labeled with 15N Mass spectrometry and NMR analyses were used to confirm the structure of the ligated protein, which was also shown to have appropriate ligand-binding properties. The ability to prepare recombinant proteins with selectively labeled segments having a single-site mutation, by using a combination of expression of fusion proteins and chemical ligation in vitro, will increase the size limits for protein structural determination in solution with NMR methods. In vitro chemical ligation of expressed protein domains will also provide a combinatorial approach to the synthesis of linked protein domains.

Iron dysregulation combined with aging prevents sepsis-induced apoptosis.

PubMed

Javadi, Pardis; Buchman, Timothy G; Stromberg, Paul E; Turnbull, Isaiah R; Vyas, Dinesh; Hotchkiss, Richard S; Karl, Irene E; Coopersmith, Craig M

2005-09-01

Sepsis, iron loading, and aging cause independent increases in gut epithelial and splenic apoptosis. It is unknown how their combination will affect apoptosis and systemic cytokine levels. Hfe-/- mice (a murine homologue of hemochromatosis) abnormally accumulate iron in their tissues. Aged (24-26 months) or mature (16-18 months) Hfe-/- mice and wild type (WT) littermates were subjected to cecal ligation and puncture (CLP) or sham laparotomy. Intestine, spleen, and blood were harvested 24 h later and assessed for apoptosis and cytokine levels. Gut epithelial and splenic apoptosis were low in both aged septic and sham Hfe-/- mice, regardless of the amount of iron in their diet. Mature septic WT mice had increased apoptosis compared to age-matched sham WT mice. Mature septic Hfe-/- mice had similar levels of intestinal cell death to age-matched septic WT mice but higher levels of splenic apoptosis. Apoptosis was significantly lower in septic aged Hfe-/- mice than septic mature Hfe-/- animals. Interleukin-6 was elevated in septic aged Hfe-/- mice compared to sham mice. Although sepsis, chronic iron dysregulation, and aging each increase gut and splenic apoptosis, their combination yields cell death levels similar to sham animals despite the fact that aged Hfe-/- mice are able to mount an inflammatory response following CLP and mature Hfe-/- mice have elevated sepsis-induced apoptosis. Combining sepsis with two risk factors that ordinarily increase cell death and increase mortality in CLP yields an apoptotic response that could not have been predicted based upon each element in isolation.

Selective desulfurization of cysteine in the presence of Cys(Acm) in polypeptides obtained by native chemical ligation.

PubMed

Pentelute, Brad L; Kent, Stephen B H

2007-02-15

Increased versatility for the synthesis of proteins and peptides by native chemical ligation requires the ability to ligate at positions other than Cys. Here, we report that Raney nickel can be used under standard conditions for the selective desulfurization of Cys in the presence of Cys(Acm). This simple and practical tactic enables the more common Xaa-Ala junctions to be used as ligation sites for the chemical synthesis of Cys-containing peptides and proteins. [reaction: see text].

Mechanistic insights of rapid liver regeneration after associating liver partition and portal vein ligation for stage hepatectomy.

PubMed

Moris, Demetrios; Vernadakis, Spyridon; Papalampros, Alexandros; Vailas, Michail; Dimitrokallis, Nikolaos; Petrou, Athanasios; Dimitroulis, Dimitrios

2016-09-07

To highlight the potential mechanisms of regeneration in the Associating Liver Partition and Portal vein ligation for Stage hepatectomy models (clinical and experimental) that could unlock the myth behind the extraordinary capability of the liver for regeneration, which would help in designing new therapeutic options for the regenerative drive in difficult setup, such as chronic liver diseases. Associating Liver Partition and Portal vein ligation for Stage hepatectomy has been recently advocated to induce rapid future liver remnant hypertrophy that significantly shortens the time for the second stage hepatectomy. The introduction of Associating Liver Partition and Portal vein ligation for Stage hepatectomy in the surgical armamentarium of therapeutic tools for liver surgeons represented a real breakthrough in the history of liver surgery. A comprehensive literature review of Associating Liver Partition and Portal vein ligation for Stage hepatectomy and its utility in liver regeneration is performed. Liver regeneration after Associating Liver Partition and Portal vein ligation for Stage hepatectomy is a combination of portal flow changes and parenchymal transection that generate a systematic response inducing hepatocyte proliferation and remodeling. Associating Liver Partition and Portal vein ligation for Stage hepatectomy represents a real breakthrough in the history of liver surgery because it offers rapid liver regeneration potential that facilitate resection of liver tumors that were previously though unresectable. The jury is still out though in terms of safety, efficacy and oncological outcomes. As far as Associating Liver Partition and Portal vein ligation for Stage hepatectomy -induced liver regeneration is concerned, further research on the field should focus on the role of non-parenchymal cells in liver regeneration as well as on the effect of Associating Liver Partition and Portal vein ligation for Stage hepatectomy in liver regeneration in the setup of parenchymal liver disease.

Intestinal Carriage of Carbapenemase-Producing Organisms: Current Status of Surveillance Methods

PubMed Central

Jacobs, Michael R.; Wilson, Brigid; Kaye, Keith; Donskey, Curtis J.; Perez, Federico

2015-01-01

SUMMARY Carbapenemases have become a significant mechanism for broad-spectrum β-lactam resistance in Enterobacteriaceae and other Gram-negative bacteria such as Pseudomonas and Acinetobacter spp. Intestinal carriage of carbapenemase-producing organisms (CPOs) is an important source of transmission. Isolation of carriers is one strategy that can be used to limit the spread of these bacteria. In this review, we critically examine the clinical performance, advantages, and disadvantages of methods available for the detection of intestinal carriage of CPOs. Culture-based methods (Centers for Disease Control and Prevention [CDC] protocols, chromogenic media, specialized agars, and double-disk synergy tests) for detecting carriage of CPOs are convenient due to their ready availability and low cost, but their limited sensitivity and long turnaround time may not always be optimal for infection control practices. Contemporary nucleic acid amplification techniques (NAATs) such as real-time PCR, hybridization assays, loop-mediated isothermal amplification (LAMP), or a combined culture and NAAT approach may provide fast results and/or added sensitivity and specificity compared with culture-based methods. Infection control practitioners and clinical microbiologists should be aware of the strengths and limitations of available methods to determine the most suitable approach for their medical facility to fit their infection control needs. PMID:26511484

Congenital Vitelline Band Causing Intestinal Obstruction in an Adult with a Double Inferior Vena Cava

PubMed Central

Pussepitiya, Kumari; Samarasinghe, Bandula; Wickramasinghe, Nuwan

2016-01-01

Introduction. Vitelline artery remnants are rare causes of intra-abdominal bands leading to bowel obstruction. These bands may be associated with Meckel's diverticulum. Double inferior vena cava (IVC) is a rare presentation and is usually identified incidentally. Case Presentation. A sixty-year-old male presented with progressive vomiting for five days and he was clinically diagnosed with intestinal obstruction. Plain X-ray abdomen showed evidence of small bowel obstruction. CT scan of the abdomen revealed dilated small bowel loops with a small outpouching in the distal ileum with a band like structure attached to it. In the CT, left sided patent IVC draining into the left renal vein was identified. Left external iliac vein was in continuity with the left IVC. Left internal iliac vein was draining into the right IVC. Exploratory laparotomy revealed a Meckel's diverticulum with a band identified as the vitelline remnant attached to its apex and inserting at the anterior abdominal wall near the umbilicus. Discussion. Meckel's diverticulum with vitelline bands, although rare, should be borne in mind in adult patients with intestinal obstruction. Identification of this anomaly can be difficult in imaging studies. Presence of double IVC should be mentioned in the imaging findings to prevent possible catastrophic complications during surgery. PMID:27843667

An oxazetidine amino acid for chemical protein synthesis by rapid, serine-forming ligations

NASA Astrophysics Data System (ADS)

Pusterla, Ivano; Bode, Jeffrey W.

2015-08-01

Amide-forming ligation reactions allow the chemical synthesis of proteins by the union of unprotected peptide segments, and enable the preparation of protein derivatives not accessible by expression or bioengineering approaches. The native chemical ligation (NCL) of thioesters and N-terminal cysteines is unquestionably the most successful approach, but is not ideal for all synthetic targets. Here we describe the synthesis of an Fmoc-protected oxazetidine amino acid for use in the α-ketoacid-hydroxylamine (KAHA) amide ligation. When incorporated at the N-terminus of a peptide segment, this four-membered cyclic hydroxylamine can be used for rapid serine-forming ligations with peptide α-ketoacids. This ligation operates at low concentration (100 μM-5 mM) and mild temperatures (20-25 °C). The utility of the reaction was demonstrated by the synthesis of S100A4, a 12 kDa calcium-binding protein not easily accessible by NCL or other amide-forming reactions due to its primary sequence and properties.

Digestion-ligation-only Hi-C is an efficient and cost-effective method for chromosome conformation capture.

PubMed

Lin, Da; Hong, Ping; Zhang, Siheng; Xu, Weize; Jamal, Muhammad; Yan, Keji; Lei, Yingying; Li, Liang; Ruan, Yijun; Fu, Zhen F; Li, Guoliang; Cao, Gang

2018-05-01

Chromosome conformation capture (3C) technologies can be used to investigate 3D genomic structures. However, high background noise, high costs, and a lack of straightforward noise evaluation in current methods impede the advancement of 3D genomic research. Here we developed a simple digestion-ligation-only Hi-C (DLO Hi-C) technology to explore the 3D landscape of the genome. This method requires only two rounds of digestion and ligation, without the need for biotin labeling and pulldown. Non-ligated DNA was efficiently removed in a cost-effective step by purifying specific linker-ligated DNA fragments. Notably, random ligation could be quickly evaluated in an early quality-control step before sequencing. Moreover, an in situ version of DLO Hi-C using a four-cutter restriction enzyme has been developed. We applied DLO Hi-C to delineate the genomic architecture of THP-1 and K562 cells and uncovered chromosomal translocations. This technology may facilitate investigation of genomic organization, gene regulation, and (meta)genome assembly.

Vitamin K1 attenuates bile duct ligation-induced liver fibrosis in rats.

PubMed

Jiao, Kun; Sun, Quan; Chen, Baian; Li, Shengli; Lu, Jing

2014-06-01

Vitamin K1 is used as a liver protection drug for cholestasis-induced liver fibrosis in China, but the mechanism of vitamin K1's action in liver fibrosis is unclear. In this study, a model of liver fibrosis was achieved via bile duct ligation in rats. The rats were then injected with vitamin K1, and the levels of serum aspartate aminotransferase, alanine transaminase, total bilirubin and the fibrotic grade score, collagen content, the expressions of α-smooth muscle actin (SMA) and cytokeratin 19 (CK19) were measured on day 28 after ligation. The levels of the biochemical parameters, fibrotic score and collagen content were significantly reduced by treatment with vitamin K1 in bile duct-ligated rats. In addition, α-SMA and CK19 expression was significantly reduced by vitamin K1 treatment in bile duct-ligated rats. These results suggested that vitamin K1 may attenuate liver fibrosis by inhibiting hepatic stellate cell activation in bile duct-ligated rats.

Emergency treatment of esophageal varix incarceration in the endoscope and ligation device during endoscopic variceal rubber band ligation

PubMed Central

Zhao, Hong; Cheng, Jilin; Xu, Yahong; Lu, Cuili; Huang, Shaoping; Fan, Zhenyu; Shi, Yuxin

2014-01-01

Sclerotherapy and endoscopic esophageal variceal ligation (EVL) are commonly used to treat and prevent variceal bleeding. As of today, there has been no report on an unexpected incarceration of a varix hooked on with the bands from the endoscopic EVL device. We recently experienced this emergency while using the 7-band ring endoscopic EVL device (Boston Scientific Corp., Boston, MA) for prophylaxis of variceal bleeding. In this case, the varix body itself was accidently incarcerated in the crevice of the esophageal endoscope after highly negative pressure of absorption was applied on the endoscope. In this situation, using force to take out the gastroscope was not an option as it would tear the vein and cause massive hemorrhage. We were managed to ligate the varix with rubber bands while releasing the incarceration. We observed that ligation of the varix at the same position using all seven ligation bands resulted in disappearance of the targeted varix. The surrounding esophageal mucosa became smooth after the treatment. PMID:25550983

Single session treatment for bleeding hemorrhoids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weinstein, S.J.; Rypins, E.B.; Houck, J.

1987-12-01

Fifty consecutive outpatients with bleeding internal hemorrhoids were prospectively treated with a single application of rubber band ligation or infrared coagulation. Complete follow-up observation was obtained in 48 patients (23 underwent rubber band ligation and 25 underwent infrared coagulation). At one month after treatment, 22 patients who underwent rubber band ligation and 16 who underwent infrared coagulation, were symptomatically improved (p less than 0.05). At six months, 15 patients who had undergone rubber band ligation and ten who had infrared coagulation treatment, remained improved (p less than 0.05). There was no statistical difference in the discomfort experienced by either groupmore » during or after the procedure as determined by a self-assessment scale. Two patients who underwent rubber band ligation experienced complications--a thrombosed external hemorrhoid developed in one patient and another had delayed rectal bleeding. Although associated with occasional complications after treatment, rubber band ligation is more effective than in infrared coagulation for single session treatment of bleeding internal hemorrhoids.« less

Effects of cholestasis on learning and locomotor activity in bile duct ligated rats.

PubMed

Hosseini, Nasrin; Alaei, Hojjatallah; Nasehi, Mohammad; Radahmadi, Maryam; Mohammad Reza, Zarrindast

2014-01-01

Cognitive functions are impaired in patients with liver disease. Bile duct ligation causes cholestasis that impairs liver function. This study investigated the impact of cholestasis progression on the acquisition and retention times in the passive avoidance test and on the locomotor activity of rats. Cholestasis was induced in male Wistar rats by ligating the main bile duct. Locomotor activity, learning and memory were assessed by the passive avoidance learning test at day 7, day 14, and day 21 post-bile duct ligation. The serum levels of bilirubin, alanine aminotransferase, and alkaline phosphatase were measured. The results showed that acquisition time and locomotor activity were not affected at day 7 and day 14, but they were significantly (P < 0.05) impaired at day 21 post-bile duct ligation compared with the results for the control group. Additionally, memory was significantly impaired on day 7 (P < 0.01), day 14, and day 21 (P < 0.001) compared with the control groups. The levels of total bilirubin, direct bilirubin, indirect bilirubin, alanine aminotransferase, and alkaline phosphatase were significantly higher at day 7, day 14, and day 21 post-bile duct ligation compared with the levels in the sham group. Based on these findings, both liver and memory function were affected in the early stage of cholestasis (7 days after bile duct ligation), while learning and locomotor activity were impaired at 21 days after bile duct ligation following the progression of cholestasis.

Comparison of infrared coagulation and rubber band ligation for first and second degree haemorrhoids: a randomised prospective clinical trial.

PubMed Central

Templeton, J L; Spence, R A; Kennedy, T L; Parks, T G; Mackenzie, G; Hanna, W A

1983-01-01

One hundred and thirty seven previously untreated out-patients with first and second degree haemorrhoids were allocated at random to treatment by infrared coagulation (n=66) or rubber band ligation (n=71). Complete follow up was obtained in 122 patients (60 who had undergone infrared coagulation (group 1), and 62 rubber band ligation (group 2)) at periods from three months to one year after completion of treatment. Infrared coagulation produced a satisfactory outcome in 51 patients (85%): 34 were rendered asymptomatic and 17 improved. Rubber band ligation produced a satisfactory outcome in 57 patients (92%): 33 were rendered asymptomatic and 24 improved. Both methods were equally effective in first and second degree haemorrhoids. The incidence of side effects, particularly discomfort, during and after treatment was significantly higher in those treated by rubber band ligation (p less than 0.001). This appeared to be an appreciable deterrent to future patient compliance. The number of patients losing more than 24 hours from work was higher after rubber band ligation than after infrared coagulation. The number of treatments necessary to cure symptoms did not differ significantly between the two methods. Infrared coagulation was significantly faster than rubber band ligation (p less than 0.001). Infrared coagulation is a simple, fast, and effective outpatient method for the treatment of first and second degree haemorrhoids with fewer troublesome side effects and higher patient acceptability than rubber band ligation. PMID:6404471

Vocal cord paralysis post patent ductus arteriosus ligation surgery: risks and co-morbidities.

PubMed

Rukholm, Gavin; Farrokhyar, Forough; Reid, Diane

2012-11-01

1. To determine the prevalence of left vocal cord paralysis (LVCP) post patent ductus arteriosus (PDA) ligation at a Tertiary Care Centre. 2. To identify risk factors associated with LVCP. 3. To identify co-morbidities associated with LVCP. 4. To determine the frequency of pre- and post-operative nasopharyngolaryngoscopic (NPL) examination in this patient population. Retrospective chart review of all infants who underwent PDA ligation surgery at a tertiary care academic hospital between July 2003 and July 2010. Data on patient age, gender, weight, method of PDA ligation, and results of NPL scoping were collected, as well as patient co-morbidities post PDA ligation. One hundred and fifteen patients underwent PDA ligation surgery. Four patients were excluded due to bilateral vocal cord paralysis. Of the remaining 111 patients, nineteen patients (17.1%) were found to have LVCP. Low birth weight was identified as a significant risk factor for LVCP (p=0.002). Gastroesophageal reflux was identified as a significant co-morbidity associated with LVCP post PDA ligation (p=0.002). Only 0.9% of patients were scoped pre-operatively, and 27.9% were scoped postoperatively. LVCP is associated with multiple morbidities. The authors strongly recommend routine post-operative scoping of all patients post PDA ligation surgery, and preoperative scoping when possible. A prospective study is warranted, in order to confirm the prevalence of LVCP as well as risk factors and associated co-morbidities. Crown Copyright © 2012. Published by Elsevier Ireland Ltd. All rights reserved.

Sac ligation in inguinal hernia repair: A meta-analysis of randomized controlled trials.

PubMed

Kao, Chun-Yu; Li, Ching-Li; Lin, Chao-Chun; Su, Chih-Ming; Chen, Chia-Che; Tam, Ka-Wai

2015-07-01

Traditionally, hernia sac ligation during inguinal hernia repair is considered mandatory to prevent postoperative development of hernia. However, ligation may induce postoperative pain. The aim of this study was to evaluate the outcomes of hernia sac ligation after inguinal hernia repair. We conducted a systematic review and meta-analysis of randomized controlled trials to investigate the outcomes of hernia sac ligation for open or laparoscopic inguinal hernia repair. Incidence of hernia recurrence was assessed following the surgery. The secondary outcomes included pain scores and postoperative complications. Five trials were selected and their results were summarized. These 5 trials were published between 1984 and 2014, and the sample sizes ranged from 50 to 467 patients. Four trials had recruited patients with inguinal hernia who underwent open repair, and one study enrolled patients who underwent laparoscopic procedures. We observed no difference in the incidence of hernia recurrence and postoperative complications between the sac ligation and nonligation groups. Postoperatively, the intensity of pain was significantly higher in the ligation group than in the nonligation group at Day 7 (Weight mean difference 1.46; 95% confident interval: 0.98-1.95). Hernia sac ligation was associated with higher postoperative pain, and did not show any benefit over sac nonligation regarding the incidence of recurrence and postoperative complications in patients undergoing open tension-free mesh repair or laparoscopic procedures. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

Insights into the Photoprotective Switch of the Major Light-harvesting Complex II (LHCII)

PubMed Central

Sunku, Kiran; de Groot, Huub. J. M.; Pandit, Anjali

2013-01-01

Light-harvesting antennae of the LHC family form transmembrane three-helix bundles of which two helices are interlocked by conserved arginine-glutamate (Arg-Glu) ion pairs that form ligation sites for chlorophylls. The antenna proteins of photosystem II have an intriguing dual function. In excess light, they can switch their conformation from a light-harvesting into a photoprotective state, in which the excess and harmful excitation energies are safely dissipated as heat. Here we applied magic angle spinning NMR and selective Arg isotope enrichment as a noninvasive method to analyze the Arg structures of the major light-harvesting complex II (LHCII). The conformations of the Arg residues that interlock helix A and B appear to be preserved in the light-harvesting and photoprotective state. Several Arg residues have very downfield-shifted proton NMR responses, indicating that they stabilize the complex by strong hydrogen bonds. For the Arg Cα chemical shifts, differences are observed between LHCII in the active, light-harvesting and in the photoprotective, quenched state. These differences are attributed to a conformational change of the Arg residue in the stromal loop region. We conclude that the interlocked helices of LHCII form a rigid core. Consequently, the LHCII conformational switch does not involve changes in A/B helix tilting but likely involves rearrangements of the loops and helical segments close to the stromal and lumenal ends. PMID:23629658

The impact of a dedicated patent ductus arteriosus ligation team on neonatal health-care outcomes.

PubMed

Resende, M H F; More, K; Nicholls, D; Ting, J; Jain, A; McNamara, P J

2016-06-01

The decision to perform patent ductus arteriosus (PDA) ligation is controversial. Patient selection is oftentimes poorly standardized, leading to delays in referral and inappropriate intervention. A system for PDA ligation categorization and triaging process was introduced in 2006 at a quaternary hospital in Canada to streamline referrals and enhance perioperative care. We aimed to evaluate the impact of this dedicated PDA ligation triaging system comparing pre- and postimplementation of this system. We performed a retrospective chart review. Demographic and cardiorespiratory data of neonates ⩽30 weeks gestation age at birth, who were referred for and/or had a PDA ligation performed during two distinct epochs (EPOCH 1 (2003 to 2005) and EPOCH 2 (2010 to 2012)), were analyzed. All surgeries were performed at The Hospital for Sick Children, the regional referral center for PDA ligation. The primary outcome was incidence of PDA ligation and procedural cancellations. Secondary outcomes included postoperative need for cardiovascular or respiratory support. Subgroup analysis was performed in neonates <1000 vs >1000 g at the time of surgery during both epochs. A total of 198 neonates underwent surgery with no difference in baseline demographics between epochs. The incidence of PDA ligation as a proportion of total live births under 30 weeks in Central East Region of Ontario was lower in the second epoch (EPOCH 1: 117/1092 (10.7%) vs EPOCH 2: 81/1520 (5.3%)). During the second epoch, 24% of referrals for surgery were canceled after review by our PDA ligation team. There were no overall differences in the proportion of neonates with oxygenation failure, ventilation failure or Post-Ligation Cardiac Syndrome (PLCS), after surgery, between epochs. The proportion of neonates who developed systemic hypotension was higher in patients <1000 g (n=34 (34%) vs n=17 (17.4%), P=0.01) at the time of surgery. In addition, we identified a reduction in the proportion of neonates <1000 g who developed PLCS in EPOCH 2. On the contrary, there was an increase in the proportion of neonates >1000 g who developed ventilation failure in EPOCH 2. The presence of dedicated triaging and management system enhances efficiency of referral process through careful selection of patients for PDA ligation and optimizes perioperative management. We demonstrated a reduction in the incidence of PDA ligation without any negative impact on short-term neonatal morbidity. The use of targeted neonatal echocardiography in the assessment of PDA shunt volume and guiding postoperative decision making is likely to have contributed to these findings.

Friction behavior of self-ligating and conventional brackets with different ligature systems.

PubMed

Szczupakowski, Alexandra; Reimann, Susanne; Dirk, Cornelius; Keilig, Ludger; Weber, Anna; Jäger, Andreas; Bourauel, Christoph

2016-07-01

Self-ligating brackets are widely believed to offer better clinical efficiency and, in particular, less friction. Thus, the goal of this in vitro investigation was to assess the friction behavior of different bracket/archwire/ligature combinations during simulated canine retraction. An important aspect of this work was to determine whether conventional bracket systems behave differently in passive or active self-ligating brackets used with a Slide™ ligature, an elastic ligature, or a steel ligature. Three conventional (Contour, Class One; Discovery(®), Dentaurum; Mystique MB, GAC) and six self-ligating (Carriere SL, Class One; Clarity™ SL, 3M Unitek; Damon3, Ormco; In-Ovation(®) C, GAC; Speed Appliance, Speed System™; QuicKlear(®), Forestadent(®)) bracket systems were analyzed. All brackets featured a 0.022″ slot (0.56 mm). Each conventional system was tested with a steel ligature (0.25 mm; Remanium(®), Dentaurum), an elastic ligature (1.3 mm in diameter; Dentalastics, Dentaurum), and a modified elastic ligature (Slide™; Leone(®)). Each combination was used with four archwires, including rectangular stainless steel (0.46 × 0.64 mm, 0.018 × 0.025″, Dentaurum), rectangular nickel-titanium with Teflon coating (0.46 × 0.64 mm, 0.018 × 0.025″, Forestadent(®)), round coaxial nickel-titanium (0.46 mm, 0.018″, Speed), and half-round/half-square (D-profile) stainless steel (0.46 mm, 0.018″, Speed). In the orthodontic measurement and simulation system (OMSS), retraction of a canine was simulated on a Frasaco model replicated in resin. Based on the force systems, the respective friction values were determined. For each combination of materials, five brackets of the same type were tested and five single measurements performed. Friction values were found to vary distinctly with the different combinations, modifiers being the ligature systems and the archwire types. Any significant friction differences between the steel-ligated, Slide™-ligated, and self-ligated brackets were sporadic. All three systems were associated with average friction values of 40 %. Active self-ligating brackets and elastic-ligated conventional brackets, by contrast, generally differed significantly from the three above-mentioned bracket systems and showed distinctly higher friction values averaging 59 and 67 %, respectively. While passive self-ligating bracket systems have frequently been touted as advantageous in the literature, they should not be regarded as the only favorable system. Steel-ligated and Slide™-ligated conventional bracket systems are capable of offering similar friction performance.

Functional and structural characterization of a β-glucosidase involved in saponin metabolism from intestinal bacteria.

PubMed

Yan, Shan; Wei, Peng-Cheng; Chen, Qiao; Chen, Xin; Wang, Shi-Cheng; Li, Jia-Ru; Gao, Chuan

2018-02-19

Saponins are natural glycosides widely used in medicine and the food industry. Although saponin metabolism in human is dependent on intestinal microbes, few involving bacteria enzymes have been identified. We cloned BlBG3, a GH3 β-glucosidase from Bifidobacterium longum, from human stool. We found that BlBG3 catalyzes the hydrolysis of glycoside furostanol and ginsenoside Rb1 at higher efficiency than other microbial β-glucosidases. Structural analysis of BlBG3 in complex with d-glucose revealed its three unique loops, which form a deep pocket and participate in substrate binding. To understand how substrate is bound to the pocket, molecular docking was performed and the binding interactions of protobioside with BlBG3 were revealed. Mutational study suggested that R484 and H642 are critical for enzymatic activity. Our study presents the first structural and functional analysis of a saponin-processing enzyme from human microbiota. Copyright © 2018 Elsevier Inc. All rights reserved.

Non perianal fistulas in Crohn's disease and short bowel syndrome: what we can do?

PubMed

Zildzic, Muharem; Alibegovic, Ervin

2009-01-01

Crohn's disease (CD) is a lifelong disease arising from an interaction between genetic and environmental factors, but seen predominantly in the developed countries of the world. The precise etiology is unknown and therefore a causal treatment is not yet available. Fistulating Crohn's disease includes fistulas arising in the perianal area, together with those communicating between the intestine and other organs or the abdominal wall. Non perianal fistulas include fistulas communicating with other viscera (urinary bladder, vagina), loops of intestine (enteroenteral fistulas) or the abdominal wall (enterocutaneus fistulas). The diagnostic approach is a crucial aspect in the management of fistulating CD as the findings influence the therapeutic strategy. Short bowel syndrome caused by extensive bowel resection should be initially treated with nutritional support and can caused serious treatment and reevaluating problems. We review this uncommon manifestation in a high risk patient after multiple operations and severely shortened bowel and also with non perianal fistulating CD.

Enteric colonization by staphylococcus delphini in four ferret kits with diarrhoea.

PubMed

Gary, J M; Langohr, I M; Lim, A; Bolin, S; Bolin, C; Moore, I; Kiupel, M

2014-11-01

Four, 1-to 4-week-old ferret kits were submitted to the Diagnostic Center for Population and Animal Health at Michigan State University for post-mortem examination. Grossly, multiple bowel loops in all ferret kits were distended by mucoid faecal material. Microscopically, there was no evidence of inflammation or notable alteration to the normal mucosal morphology. Gram-positive coccoid bacteria colonized variable segments of the small intestine. These bacteria were identified as Staphylococcus delphini by phenotypic and molecular analyses. Enzyme-linked immunosorbent assay for detection of Staphylococcus enterotoxins was positive and polymerase chain reaction detected the gene for Staphylococcus enterotoxin E in the isolates. The hypersecretory diarrhoea in these ferret kits may have been associated with colonization of the small intestine by S. delphini, cultures of which were shown in vitro to be potentially capable of producing enterotoxin E. The condition described in these ferrets is similar to 'sticky' kit syndrome in mink. Copyright © 2014 Elsevier Ltd. All rights reserved.

[A rare case of intussusception in a seventeen year old boy: diagnosis, management and review of the literature.

PubMed

Rossi, Enrica; Basile, Massimo; Narese, Donatella; Ognibene, Noemi; Poggesi, Sara; Cangelosi, Marta; Defilippi, Claudio

2017-04-01

Intussusception is the most common cause of intestinal obstruction and acute abdomen in the first year of life. Approximately in the 80% of cases intussusception occurs when the last ileal loop is pulled into the cecum, passing through the ileocecal valve, and finally resulting in the displacement of cecum in the upper abdominal. It could be related with mesenteric adenitis because enlarged lymph nodes, together with peristalsis, can serve as "lead point". Other forms of intussusception are ileo-ileal and colo-colic. The aetiology in infants and adults can be very variable and most often linked with secondary causes, such as benign or malignant lesions (polyps, tumors, lymphomas, intestinal duplication cyst, Meckel's diverticulum). In this paper we describe a rare case of idiopathic ileo-ileal intussusception in a 17 year old boy. We also discuss, with a careful analysis of the literature, the diagnostic and therapeutic protocol in case of intussusception ileo-colic approved at the Meyer Children's Hospital.

Some properties of purified Escherichia coli heat-stable enterotoxin II.

PubMed Central

Hitotsubashi, S; Fujii, Y; Yamanaka, H; Okamoto, K

1992-01-01

We examined the biological properties of purified Escherichia coli heat-stable enterotoxin II (STII) using mouse intestinal loop assays and compared these properties with those of heat-stable enterotoxin I (STI) and cholera toxin (CT). The action of STII over time differed from those of STI and CT. STII did not alter cyclic GMP or cyclic AMP levels in intestinal mucosal cells. Our results supported the idea that the mechanism of action of STII in inducing fluid secretion is different from the mechanisms of action of STI and CT. This hypothesis was further supported by the fact that an anti-STII neutralizing serum did not neutralize the activities of STI and CT. Subsequently, we examined the involvement of prostaglandins in the action of STII. The level of prostaglandin E2 in the fluid accumulated as a result of the action of STII increased, and the prostaglandin synthesis inhibitors aspirin and indomethacin significantly reduced the response to STII. These results implicate prostaglandin E2 in the mechanism of action of STII. Images PMID:1398961

Unexpected substrate specificity of T4 DNA ligase revealed by in vitro selection

NASA Technical Reports Server (NTRS)

Harada, Kazuo; Orgel, Leslie E.

1993-01-01

We have used in vitro selection techniques to characterize DNA sequences that are ligated efficiently by T4 DNA ligase. We find that the ensemble of selected sequences ligates about 50 times as efficiently as the random mixture of sequences used as the input for selection. Surprisingly many of the selected sequences failed to produce a match at or close to the ligation junction. None of the 20 selected oligomers that we sequenced produced a match two bases upstream from the ligation junction.

Perirectal sepsis after rubber band ligation of haemorrhoids : a case report.

PubMed

Duchateau, A; Huyghe, M

2014-01-01

Rubber band ligation (Barron ligation, RBL) is a widely used method for the treatment of symptomatic -haemorrhoids. In general, it is considered as a safe, effective and easily performed way of treating second and third -degree haemorrhoids. Perineal and pelvic sepsis was already known to be a rare, but possible complication after stapled haemorrhoidopexy. However, there have been some reports of severe sepsis after rubber band ligation as well. We -present a patient who was treated twice for haemorrhoids with rubber band ligation and attended the emergency department 10 days later. He was diagnosed with perirectal sepsis and aggressive antibiotic treatment was the first attempt of treatment. Because of further deterioration under medical therapy, our patient required extensive surgery. Copyright© Acta Chirurgica Belgica.

Rubber band ligation of hemorrhoids: A guide for complications

PubMed Central

Albuquerque, Andreia

2016-01-01

Rubber band ligation is one of the most important, cost-effective and commonly used treatments for internal hemorrhoids. Different technical approaches were developed mainly to improve efficacy and safety. The technique can be employed using an endoscope with forward-view or retroflexion or without an endoscope, using a suction elastic band ligator or a forceps ligator. Single or multiple ligations can be performed in a single session. Local anaesthetic after ligation can also be used to reduce the post-procedure pain. Mild bleeding, pain, vaso-vagal symptoms, slippage of bands, priapism, difficulty in urination, anal fissure, and chronic longitudinal ulcers are normally considered minor complications, more frequently encountered. Massive bleeding, thrombosed hemorrhoids, severe pain, urinary retention needing catheterization, pelvic sepsis and death are uncommon major complications. Mild pain after rubber band ligation is the most common complication with a high frequency in some studies. Secondary bleeding normally occurs 10 to 14 d after banding and patients taking anti-platelet and/or anti-coagulant medication have a higher risk, with some reports of massive life-threatening haemorrhage. Several infectious complications have also been reported including pelvic sepsis, Fournier’s gangrene, liver abscesses, tetanus and bacterial endocarditis. To date, seven deaths due to these infectious complications were described. Early recognition and immediate treatment of complications are fundamental for a favourable prognosis. PMID:27721924

The RtcB RNA ligase is an essential component of the metazoan unfolded protein response.

PubMed

Kosmaczewski, Sara Guckian; Edwards, Tyson James; Han, Sung Min; Eckwahl, Matthew J; Meyer, Benjamin Isaiah; Peach, Sally; Hesselberth, Jay R; Wolin, Sandra L; Hammarlund, Marc

2014-12-01

RNA ligation can regulate RNA function by altering RNA sequence, structure and coding potential. For example, the function of XBP1 in mediating the unfolded protein response requires RNA ligation, as does the maturation of some tRNAs. Here, we describe a novel in vivo model in Caenorhabditis elegans for the conserved RNA ligase RtcB and show that RtcB ligates the xbp-1 mRNA during the IRE-1 branch of the unfolded protein response. Without RtcB, protein stress results in the accumulation of unligated xbp-1 mRNA fragments, defects in the unfolded protein response, and decreased lifespan. RtcB also ligates endogenous pre-tRNA halves, and RtcB mutants have defects in growth and lifespan that can be bypassed by expression of pre-spliced tRNAs. In addition, animals that lack RtcB have defects that are independent of tRNA maturation and the unfolded protein response. Thus, RNA ligation by RtcB is required for the function of multiple endogenous target RNAs including both xbp-1 and tRNAs. RtcB is uniquely capable of performing these ligation functions, and RNA ligation by RtcB mediates multiple essential processes in vivo. © 2014 The Authors.

The RtcB RNA ligase is an essential component of the metazoan unfolded protein response

PubMed Central

Kosmaczewski, Sara Guckian; Edwards, Tyson James; Han, Sung Min; Eckwahl, Matthew J; Meyer, Benjamin Isaiah; Peach, Sally; Hesselberth, Jay R; Wolin, Sandra L; Hammarlund, Marc

2014-01-01

RNA ligation can regulate RNA function by altering RNA sequence, structure and coding potential. For example, the function of XBP1 in mediating the unfolded protein response requires RNA ligation, as does the maturation of some tRNAs. Here, we describe a novel in vivo model in Caenorhabditis elegans for the conserved RNA ligase RtcB and show that RtcB ligates the xbp-1 mRNA during the IRE-1 branch of the unfolded protein response. Without RtcB, protein stress results in the accumulation of unligated xbp-1 mRNA fragments, defects in the unfolded protein response, and decreased lifespan. RtcB also ligates endogenous pre-tRNA halves, and RtcB mutants have defects in growth and lifespan that can be bypassed by expression of pre-spliced tRNAs. In addition, animals that lack RtcB have defects that are independent of tRNA maturation and the unfolded protein response. Thus, RNA ligation by RtcB is required for the function of multiple endogenous target RNAs including both xbp-1 and tRNAs. RtcB is uniquely capable of performing these ligation functions, and RNA ligation by RtcB mediates multiple essential processes in vivo. Subject Categories Protein Biosynthesis & Quality Control; RNA Biology PMID:25366321

Rubber band ligation of hemorrhoids: A guide for complications.

PubMed

Albuquerque, Andreia

2016-09-27

Rubber band ligation is one of the most important, cost-effective and commonly used treatments for internal hemorrhoids. Different technical approaches were developed mainly to improve efficacy and safety. The technique can be employed using an endoscope with forward-view or retroflexion or without an endoscope, using a suction elastic band ligator or a forceps ligator. Single or multiple ligations can be performed in a single session. Local anaesthetic after ligation can also be used to reduce the post-procedure pain. Mild bleeding, pain, vaso-vagal symptoms, slippage of bands, priapism, difficulty in urination, anal fissure, and chronic longitudinal ulcers are normally considered minor complications, more frequently encountered. Massive bleeding, thrombosed hemorrhoids, severe pain, urinary retention needing catheterization, pelvic sepsis and death are uncommon major complications. Mild pain after rubber band ligation is the most common complication with a high frequency in some studies. Secondary bleeding normally occurs 10 to 14 d after banding and patients taking anti-platelet and/or anti-coagulant medication have a higher risk, with some reports of massive life-threatening haemorrhage. Several infectious complications have also been reported including pelvic sepsis, Fournier's gangrene, liver abscesses, tetanus and bacterial endocarditis. To date, seven deaths due to these infectious complications were described. Early recognition and immediate treatment of complications are fundamental for a favourable prognosis.

Why is cytoskeletal contraction required for cardiac fusion before but not after looping begins?

NASA Astrophysics Data System (ADS)

Shi, Yunfei; Varner, Victor D.; Taber, Larry A.

2015-02-01

Cytoskeletal contraction is crucial to numerous morphogenetic processes, but its role in early heart development is poorly understood. Studies in chick embryos have shown that inhibiting myosin-II-based contraction prior to Hamburger-Hamilton (HH) stage 10 (33 h incubation) impedes fusion of the mesodermal heart fields that create the primitive heart tube (HT), as well as the ensuing process of cardiac looping. If contraction is inhibited at or after looping begins at HH10, however, fusion and looping proceed relatively normally. To explore the mechanisms behind this seemingly fundamental change in behavior, we measured spatiotemporal distributions of tissue stiffness, stress, and strain around the anterior intestinal portal (AIP), the opening to the foregut where contraction and cardiac fusion occur. The results indicate that stiffness and tangential tension decreased bilaterally along the AIP with distance from the embryonic midline. The gradients in stiffness and tension, as well as strain rate, increased to peaks at HH9 (30 h) and decreased afterward. Exposure to the myosin II inhibitor blebbistatin reduced these effects, suggesting that they are mainly generated by active cytoskeletal contraction, and finite-element modeling indicates that the measured mechanical gradients are consistent with a relatively uniform contraction of the endodermal layer in conjunction with constraints imposed by the attached mesoderm. Taken together, our results suggest that, before HH10, endodermal contraction pulls the bilateral heart fields toward the midline where they fuse to create the HT. By HH10, however, the fusion process is far enough along to enable apposing cardiac progenitor cells to keep ‘zipping’ together during looping without the need for continued high contractile forces. These findings should shed new light on a perplexing question in early heart development.

Influence of betaine and salinomycin on intestinal absorption of methionine and glucose and on the ultrastructure of intestinal cells and parasite developmental stages in chicks infected with Eimeria acervulina.

PubMed

Augustine, P C; Danforth, H D

1999-01-01

The effect of betaine and salinomycin on absorption of methionine and glucose in tissue from the duodenal loops of Eimeria acervulina-infected chicks was determined. Differences in the ultrastructure of the intestinal cells and parasite developmental stages were also examined. With a drug-resistant isolate of E. acervulina, methionine absorption was significantly higher in chicks fed a basal diet supplemented with 0.15% betaine as compared with absorption in chicks fed the unsupplemented basal diet. Addition of 66 ppm salinomycin to the diet containing betaine did not further enhance absorption. Conversely, with a drug-sensitive isolate, methionine absorption was significantly higher in chicks fed a diet supplemented with both betaine and salinomycin than in chicks fed the unsupplemented basal diet. Tissue from chicks fed any of the supplemented diets was usually significantly heavier than that from chicks fed the unsupplemented diet, even when weight gains of the birds were similar. Glucose absorption was similar in all diet groups. Epithelial cells in coccidia-infected and uninfected chicks fed diets supplemented with betaine or betaine plus salinomycin were less electron dense than cells from chicks fed diets that were not supplemented with betaine. Merozoites of E. acervulina in chicks fed diets supplemented with salinomycin had extensive membrane disruption and vacuolization, but the damage was prevented when betaine was added to the diet. Numerous merozoites and intact schizonts were seen in the intestinal lumen of chicks fed the diet containing betaine plus salinomycin.

Peritonitis secondary to spontaneous perforation of a primary gastrointestinal stromal tumour of the small intestine: A case report and a literature review.

PubMed

Alessiani, Mario; Gianola, Marco; Rossi, Sabina; Perfetti, Vittorio; Serra, Piero; Zelaschi, Daniela; Magnani, Enzo; Cobianchi, Lorenzo

2015-01-01

A few cases of acute abdomen caused by perforation of small-intestinal gastrointestinal stromal tumours (GISTs) have been reported in the literature. Together with a review of the published cases, here we report a case of an elderly patient with peritonitis due to spontaneous perforation of a GIST of the jejunum. An 82-year-old man was admitted to the emergency unit of our hospital with fever and severe abdominal pain. An abdominal enhanced computed tomography scan detected a 6cm solid mass in the left upper quadrant adherent to a jejunal loop and surrounded by free fluid and free air. Due to the radiological features of the mass, the diagnosis of a perforation of a GIST arising from the jejunum wall was suspected. The patient underwent emergency laparotomy. Intraoperative findings confirmed diffuse peritonitis secondary to jejunal tumour perforation. A segmental resection of the jejunum containing the mass was performed followed by a mechanical end-to-side anastomosis. The histopathologic examination of the mass confirmed the diagnosis of a perforated GIST of the small intestine (high-risk category). The post-operative course was uneventful and the patient was treated with adjuvant imatinib therapy. Twenty-one other cases of spontaneous perforation of small intestine GISTs are reported in the literature and are summarized in the present review. The described case is the tip of the iceberg and spontaneous rupture or perforation of GISTs are a far more frequent first presentation of this rare tumour. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Haemodynamic effects of a selective adenosine A2A receptor agonist, CGS 21680, in chronic heart failure in anaesthetized rats.

PubMed

Nekooeian, A A; Tabrizchi, R

1998-10-01

1. Recently we demonstrated that the administration of an A2A adenosine receptor agonist, CGS 21680, to anaesthetized rats with acute heart failure (1 h post-coronary artery ligation) resulted in an increase in cardiac output. In the present investigation, the effects of CGS 21680 on cardiac output, vascular resistance, heart rate, blood pressure and mean circulatory filling pressure (Pmcf) were investigated in anaesthetized rats with chronic heart failure (8 weeks post-coronary artery ligation). 2. Experiments were conducted in five groups (n = 6) of animals: sham-operated vehicle-treated (0.9% NaCl; 0.037 mL kg(-1) min(-1)) animals in which the occluder was placed but not pulled to ligate the coronary artery; coronary artery-ligated vehicle-treated animals; and coronary artery-ligated CGS 21680-treated (0.1. 0.3 or 1.0 microg kg(-1) min(-1)) animals. 3. Baseline blood pressure, cardiac output and rate of rise in left ventricular pressure (+dP/dt) were significantly reduced in animals with coronary artery ligation when compared to sham-operated animals. Coronary artery ligation resulted in a significant increase in left ventricular end-diastolic pressure, Pmcf and venous resistance when compared to sham-operated animals. 4. Administration of CGS 21680 at 0.3 and 1.0 microg kg(-1) min(-1) significantly (n = 6; P<0.05) increased cardiac output by 19+/-4% and 39+/-5%, and heart rate by 14+/-2% and 15+/-1%, respectively, when compared to vehicle treatment in coronary artery-ligated animals. Administration of CGS 21680 also significantly reduced blood pressure and arterial resistance when compared to coronary artery-ligated vehicle-treated animals. Infusion of CGS 21680 also significantly reduced venous resistance when compared to vehicle-treated coronary artery-ligated animals. 5. The results show that heart failure is characterized by reduced cardiac output, and increased left ventricular end-diastolic pressure, venous resistance and Pmcf. Acute treatment with CGS 21680 in animals with chronic heart failure decreased left ventricular end-diastolic pressure and increased cardiac output. This increase in cardiac output was the result of reduced arterial and venous resistances and increased heart rate.

Effect of surgical subspecialty training on patent ductus arteriosus ligation outcomes.

PubMed

Markush, Dor; Briden, Kelleigh E; Chung, Michael; Herbst, Katherine W; Lerer, Trudy J; Neff, Stephen; Wu, Amy C; Campbell, Brendan T

2014-05-01

Surgical outcomes data for patent ductus arteriosus (PDA) ligation come primarily from single institution case series. The purpose of this study was to evaluate national PDA ligation trends, and to compare outcomes between pediatric general (GEN) and pediatric cardiothoracic (CT) surgeons. The Pediatric Health Information System database was queried to identify neonates who underwent PDA ligation from 2006 through 2009. Outcomes evaluated included surgical morbidity, in-hospital mortality, length of stay, and total charges. Outcomes were compared between pediatric general and pediatric cardiothoracic surgeons. The records of 1,482 neonates who underwent PDA ligation were identified and analyzed. Overall mean gestational age was 26 ± 3 weeks and birth weight was 888 ± 428 g. The majority of patients among both surgeons had birth weights of ≤1,000 g (77.2%) and were born at ≤27-week gestation (81.5%). Most of the PDA ligations were performed by pediatric CT surgeons (n = 1,196, 80.7%). The mortality rate did not differ by surgeon subspecialty training (GEN = 5.2%, CT 7.9%, p = 0.16). Neonates in the cardiothoracic surgeon cohort showed lower length of stay (p < 0.001-0.05) and total hospital charges (p < 0.05) among patients with birth weight ≤1,200 g. Proxy measures of surgical morbidity-gastrostomy, fundoplication, and tracheostomy-showed no significant differences between the two surgical subspecialists overall or across birth weight subgroups (p > 0.05). These data provide a contemporary snapshot of PDA ligation outcomes at American children's hospitals. Pediatric general surgeons achieve comparable outcomes performing PDA ligation compared to pediatric cardiothoracic surgeons.

Amitriptyline and phenytoin prevents memory deficit in sciatic nerve ligation model of neuropathic pain.

PubMed

Abdulmajeed, Wahab Imam; Ibrahim, Ridwan Babatunde; Ishola, Azeez Olakunle; Balogun, Wasiu Gbolahan; Cobham, Ansa Emmanuel; Amin, Abdulbasit

2016-03-01

Phenytoin and amitriptyline are often reported to attenuate pain in chronic conditions. Information on their ability to ameliorate cognitive impairment associated with neuropathic pain remains unclear due to mixed results from studies. This study investigated the effects of phenytoin and amitriptyline on memory deficit associated with neuropathic pain. Twenty-eight adult male Wistar rats were randomly divided into four groups: A, B, C, and D (n=7). Groups A, B, C, and D served as sham control, sciatic nerve ligated untreated, sciatic nerve ligated receiving amitriptyline (5 mg/kg), and sciatic nerve ligated receiving phenytoin (10 mg/kg) respectively. Treatments lasted for 14 days, after which both 'Y' maze and novel object recognition test (NOR) were performed. On the last day of treatment, the animals were anesthetized and their brain excised, and the prefrontal cortices and sciatic nerve were processed histologically using hematoxylin and eosin. There was memory impairment in the sciatic nerve ligated untreated group which was statistically significant (p<0.05) when compared to the phenytoin-treated, amitriptyline-treated, and sham control groups using the 'Y' maze and NOR tests. Histological quantification showed that the prefrontal cortices of the ligated animals showed increased neural population in comparison to normal control. These increases were significantly marked in the untreated ligated group. Sciatic nerve of untreated ligated group showed high demyelination and axonal degeneration which was ameliorated in the treated animals. The administration of amitriptyline and phenytoin can ameliorate neuronal injury, demyelination, and memory impairment associated with neuropathic pain in Wistar rats.

The effect of ligation on the load deflection characteristics of nickel titanium orthodontic wire.

PubMed

Kasuya, Shugo; Nagasaka, Satoshi; Hanyuda, Ai; Ishimura, Sadao; Hirashita, Ayao

2007-12-01

This study examined the effect of ligation on the load-deflection characteristics of nickel-titanium (NiTi) orthodontic wire. A modified three-point bending system was used for bending the NiTi round wire, which was inserted and ligated in the slots of three brackets, one of which was bonded to each of the three bender rods. Three different ligation methods, stainless steel ligature (SSL), slot lid (SL), and elastomeric ligature (EL), were employed, as well as a control with neither bracket nor ligation (NBL). The tests were repeated five times under each condition. Comparisons were made of load-deflection curve, load at maximum deflection of 2,000 microm, and load at a deflection of 1,500 microm during unloading. Analysis of Variance (ANOVA) and Dunnett's test were conducted to determine method difference (alpha = 0.05). The interaction between deflection and ligation was tested, using repeated-measures ANOVA (alpha = 0.05). The load values of the ligation groups were two to three times greater than the NBL group at a deflection of 1,500 microm during unloading: 4.37 N for EL, 3.90 N for SSL, 3.02 N for SL, and 1.49 N for NBL (P < 0.01). For the EL, a plateau region disappeared in the unloading curve. SL showed the smallest load. The ligation of the bracket wire may make NiTi wire exhibit a significantly heavier load than that traditionally expected. NiTi wire exhibited the majority of its true superelasticity with SL, whereas EL may act as a restraint on its superelasticity.

Propranolol, isosorbide mononitrate and endoscopic band ligation - alone or in varying combinations for the prevention of esophageal variceal rebleeding.

PubMed

Ahmad, Irfan; Khan, Anwaar A; Alam, Altaf; Butt, Arshad Kamal; Shafqat, Farzana; Sarwar, Shahid

2009-05-01

To compare the efficacy of propranolol, propranolol with nitrate, band ligation, and band ligation with propranolol and nitrate for the prevention of esophageal variceal rebleeding. A prospective randomized trial. Department of Gastroenterology and Hepatology, Sheikh Zayed Hospital, Lahore, from November 2003 to July 2005. One hundred and sixty cirrhotic patients with esophageal variceal bleeding were randomized to four treatment groups (propranolol, propranolol plus isosorbide mononitrate, band ligation, band ligation plus propranolol and nitrate) with 40 patients in each group. Patients were followed for 6 months after the enrolment of last patient. Primary end points were recurrence of esophageal variceal bleeding and death. Treatment complications were noted. Four treatment groups were comparable regarding baseline characteristics. Esophageal variceal rebleeding occurred in 22% patients in band ligation plus drugs group, 26% patients in drug combination group, 31% patients in banding group and 38% patients in propranolol group (p=0.41). Difference in mortality rates was also not significant. There was no significant difference between treatment groups in prevention of esophageal variceal rebleeding.

Milrinone use for hemodynamic instability in patent ductus arteriosus ligation.

PubMed

Halliday, Matthew; Kavarana, Minoo; Ebeling, Myla; Kiger, James

2017-03-01

Determine if prophylactic milrinone improves cardiovascular or long-term clinical outcomes in preterm neonates who receive surgical patent ductus arteriosus (PDA) ligation. Retrospective review of 45 infants over a 4-year period that received a PDA ligation at one institution. Data were collected on morbidity and mortality outcomes for all infants as well as milrinone therapy perioperatively. Of the 45 infants that were studied 15 received milrinone in the perioperative period of PDA ligation and the remaining 30 infants did not receive milrinone. The use of milrinone showed no statistically significant improvement in acute markers of hemodynamic stability. There was also no statistically significant difference in morbidity and mortality outcomes in milrinone group compared to the non-milrinone group. Prophylactic milrinone use for premature infants following PDA ligation does not show a significant cardiovascular or long-term clinical benefit.

Heated oligonucleotide ligation assay (HOLA): an affordable single nucleotide polymorphism assay.

PubMed

Black, W C; Gorrochotegui-Escalante, N; Duteau, N M

2006-03-01

Most single nucleotide polymorphism (SNP) detection requires expensive equipment and reagents. The oligonucleotide ligation assay (OLA) is an inexpensive SNP assay that detects ligation between a biotinylated "allele-specific detector" and a 3' fluorescein-labeled "reporter" oligonucleotide. No ligation occurs unless the 3' detector nucleotide is complementary to the SNP nucleotide. The original OLA used chemical denaturation and neutralization. Heated OLA (HOLA) instead uses a thermal stable ligase and cycles of denaturing and hybridization for ligation and SNP detection. The cost per genotype is approximately US$1.25 with two-allele SNPs or approximately US$1.75 with three-allele SNPs. We illustrate the development of HOLA for SNP detection in the Early Trypsin and Abundant Trypsin loci in the mosquito Aedes aegypti (L.) and at the a-glycerophosphate dehydrogenase locus in the mosquito Anopheles gambiae s.s.

Patent Ductus Arteriosus Ligation and Adverse Outcomes: Causality or Bias?

PubMed Central

Weisz, Dany E.; McNamara, Patrick J.

2014-01-01

Observational studies have associated patent ductus arteriosus (PDA) ligation in preterm infants with increased chronic lung disease (CLD), retinopathy of prematurity, and neurodevelopmental impairment at long-term follow-up. Although the biological rationale for this association is incompletely understood, there is an emerging secular trend toward a permissive approach to the PDA. However, insufficient adjustment for postnatal, pre-ligation confounders, such as intraventricular hemorrhage and the duration and intensity of mechanical ventilation, suggests the presence of residual bias due to confounding by indication, and obliges caution in interpreting the ligation-morbidity relationship. A period of conservative management after failure of medical PDA closure may be considered to reduce the number of infants treated with surgery. Increased mortality and CLD in infants with persistent symptomatic PDA suggests that surgical ligation remains an important treatment modality for preterm infants. PMID:25024972

Late complication of open inguinal hernia repair: small bowel obstruction caused by intraperitoneal mesh migration.

PubMed

Ferrone, Roberto; Scarone, Pier Carlo; Natalini, Gianni

2003-09-01

We describe a case of small bowel obstruction due to prosthetic mesh migration. A 67-year-old male, who had undergone prosthetic repair of inguinal hernia 3 years before, was admitted for a mechanical small bowel obstruction. Laparotomy revealed the penultimate ileal loop choked by an adhesion drawing it towards a polypropylene mesh, firmly attached to the parietal peritoneum of the inguinal region. The intestinal loop was released; the mesh was embedded deep with continuous whip suture after folding the parietal peritoneum. The patient was dismissed on the 11th postoperative day surgically healed. The "tension-free" technique is undoubtedly the gold standard for hernia repair. However, it is not free of complications, mostly due to technical errors, of which the surgeon must be aware, both when he is responsible for correcting defects in the wall, as well as when he has to face an occlusion in a patient who has undergone plastic surgery for inguinal hernia.

Evaluation of the reverse transcription loop-mediated isothermal amplification (RT-LAMP) as a screening method for the detection of influenza viruses in the fecal materials of water birds.

PubMed

Yoshida, Hiromi; Sakoda, Yoshihiro; Endo, Mayumi; Motoshima, Masayuki; Yoshino, Fumi; Yamamoto, Naoki; Okamatsu, Masatoshi; Soejima, Takahiro; Senba, Syouhei; Kanda, Hidetoshi; Kida, Hiroshi

2011-06-01

Migratory water birds are a natural reservoir for influenza A viruses. Viruses replicate in the intestines of ducks and are shed with the fecal materials. Virus isolation from collected fecal materials, therefore, is an integral part of the surveillance of avian influenza in water birds. In the present study, reverse transcription loop-mediated isothermal amplification (RT-LAMP) was assessed for its usefulness in detecting the RNA of influenza A viruses in fecal materials. It was found that, RT-LAMP specifically and sensitively detects the matrix gene of influenza A viruses. Influenza A viruses were isolated from the fecal materials in which viral RNA were detected by RT-LAMP in 35 min. The present findings indicate that RT-LAMP is useful as a high throughput screening method for field samples prior to virus isolation, allowing the processing of hundreds of samples per day.

[Rubber band ligation in treatment of hemorrhoids: our experience].

PubMed

Gaj, F; Biviano, I; Sportelli, G; Candeloro, L

2015-01-01

Hemorrhoids are a very common condition. The treatment depends upon persistence and severity of symptoms. For hemorrhoids of II and III grade the rubber band ligation may be therapeutic. Our aim is to report the outcomes of rubber band ligation of hemorrhoids, with a follow up of 6 months. A total of 50 patients underwent rubber band ligation for symptomatic hemorrhoids (grade II and III) without prolapse, between June 2012 and June 2014. All patients underwent plug test to rule out presence of rectal mucosal prolapse and were classified according to PATE classification (1). Each hemorrhoid was ligated with one rubber band through a ligator. All patients were evaluated immediately at the end of the procedure, after ten days and six months after the treatment. Patient's demographic and operative data were collected and analyzed. The mean patients age was 47.6±12.3 years (range 24-72). All procedures were performed without complications. Before rubber band ligation, 42 patients had rectal bleeding, 38 had perineal discomfort and 27 had itching. Ten days after the treatment, 12 patients presented self-limited rectal bleeding, but 10 of these had more hemorrhoids and underwent a second rubber band ligation. No patients complained perineal discomfort, and 8 patients had itching; 78% and 16% of patients respectively, experienced feeling of a foreign body inside the canal anal and anal pain. After 6 months, only 13 patients were occasionally symptomatic: 4 patients had rectal bleeding, 2 had perineal discomfort and 4 had itching. Three more patients presented both perineal discomfort and hitching. None had the feeling of a foreign body in anal canal or anal pain. Rubber band ligation is an efficacious, cost-effective and simple treatment for the second and third degree hemorrhoids without rectal mucosal prolapsed. In our hands, no severe complications developed and minor complications could be handled with ease.

Convergent synthesis of proteins by kinetically controlled ligation

DOEpatents

Kent, Stephen; Pentelute, Brad; Bang, Duhee; Johnson, Erik; Durek, Thomas

2010-03-09

The present invention concerns methods and compositions for synthesizing a polypeptide using kinetically controlled reactions involving fragments of the polypeptide for a fully convergent process. In more specific embodiments, a ligation involves reacting a first peptide having a protected cysteyl group at its N-terminal and a phenylthioester at its C-terminal with a second peptide having a cysteine residue at its N-termini and a thioester at its C-termini to form a ligation product. Subsequent reactions may involve deprotecting the cysteyl group of the resulting ligation product and/or converting the thioester into a thiophenylester.

Self-ligating versus conventional metallic brackets on Streptococcus mutans retention: A systematic review.

PubMed

Longoni, Juliano N; Lopes, Beatriz M; Freires, Irlan A; Dutra, Kamile L; Franco, Ademir; Paranhos, Luiz R

2017-01-01

The present study aimed to review the literature systematically and assess comparatively whether self-ligating metallic brackets accumulate less Streptococcus mutans biofilm than conventional metallic brackets. The systematic search was performed following PRISMA guidelines and registration in PROSPERO. Seven electronic databases (Google Scholar, LILACS, Open Grey, PubMed, SciELO, ScienceDirect, and Scopus) were consulted until April 2016, with no restriction of language and time of publication. Only randomized clinical studies verifying S. mutans colonization in metallic brackets (self-ligating and conventional) were included. All steps were performed independently by two operators. The search resulted in 546 records obtained from the electronic databases. Additionally, 216 references obtained from the manual search of eligible articles were assessed. Finally, a total of 5 studies were included in the qualitative synthesis. In 1 study, the total bacterial count was not different among self-ligating and conventional brackets, whereas in 2 studies the amount was lower for self-ligating brackets. Regarding the specific count of S. mutans , 2 studies showed less accumulation in self-ligating than in conventional brackets. Based on the limited evidence, self-ligating metallic brackets accumulate less S. mutans than conventional ones. However, these findings must be interpreted in conjunction with particularities individual for each patient - such as hygiene and dietary habits, which are components of the multifactorial environment that enables S. Mutans to proliferate and keep retained in the oral cavity.

Root resorption during orthodontic treatment with self-ligating or conventional brackets: a systematic review and meta-analysis.

PubMed

Yi, Jianru; Li, Meile; Li, Yu; Li, Xiaobing; Zhao, Zhihe

2016-11-21

The aim of this study was to compare the external apical root resorption (EARR) in patients receiving fixed orthodontic treatment with self-ligating or conventional brackets. Studies comparing the EARR between orthodontic patients using self-ligating or conventional brackets were identified through electronic search in databases including CENTRAL, PubMed, EMBASE, China National Knowledge Infrastructure (CNKI) and SIGLE, and manual search in relevant journals and reference lists of the included studies until Apr 2016. The extraction of data and risk of bias evaluation were conducted by two investigators independently. The original outcome underwent statistical pooling by using Review Manager 5. Seven studies were included in the systematic review, out of which, five studies were statistically pooled in meta-analysis. The value of EARR of maxillary central incisors in the self-ligating bracket group was significantly lower than that in the conventional bracket group (SMD -0.31; 95% CI: -0.60--0.01). No significant differences in other incisors were observed between self-ligating and conventional brackets. Current evidences suggest self-ligating brackets do not outperform conventional brackets in reducing the EARR in maxillary lateral incisors, mandible central incisors and mandible lateral incisors. However, self-ligating brackets appear to have an advantage in protecting maxillary central incisor from EARR, which still needs to be confirmed by more high-quality studies.

Universal strategies for the DNA-encoding of libraries of small molecules using the chemical ligation of oligonucleotide tags

PubMed Central

Litovchick, Alexander; Clark, Matthew A; Keefe, Anthony D

2014-01-01

The affinity-mediated selection of large libraries of DNA-encoded small molecules is increasingly being used to initiate drug discovery programs. We present universal methods for the encoding of such libraries using the chemical ligation of oligonucleotides. These methods may be used to record the chemical history of individual library members during combinatorial synthesis processes. We demonstrate three different chemical ligation methods as examples of information recording processes (writing) for such libraries and two different cDNA-generation methods as examples of information retrieval processes (reading) from such libraries. The example writing methods include uncatalyzed and Cu(I)-catalyzed alkyne-azide cycloadditions and a novel photochemical thymidine-psoralen cycloaddition. The first reading method “relay primer-dependent bypass” utilizes a relay primer that hybridizes across a chemical ligation junction embedded in a fixed-sequence and is extended at its 3′-terminus prior to ligation to adjacent oligonucleotides. The second reading method “repeat-dependent bypass” utilizes chemical ligation junctions that are flanked by repeated sequences. The upstream repeat is copied prior to a rearrangement event during which the 3′-terminus of the cDNA hybridizes to the downstream repeat and polymerization continues. In principle these reading methods may be used with any ligation chemistry and offer universal strategies for the encoding (writing) and interpretation (reading) of DNA-encoded chemical libraries. PMID:25483841

Association of Patent Ductus Arteriosus Ligation With Death or Neurodevelopmental Impairment Among Extremely Preterm Infants

PubMed Central

Mirea, Lucia; Rosenberg, Erin; Jang, Maximus; Ly, Linh; Church, Paige T.; Kelly, Edmond; Kim, S. Joseph; Jain, Amish; McNamara, Patrick J.; Shah, Prakesh S.

2017-01-01

Importance Observational studies have associated patent ductus arteriosus (PDA) ligation among preterm infants with adverse neonatal outcomes and neurodevelopmental impairment in early childhood, with a resultant secular trend away from surgical treatment. However, to our knowledge, studies have inadequately addressed sources of residual bias, including survival bias and major neonatal morbidities arising before exposure to ligation. Objective Evaluate the association between PDA ligation vs medical management and neonatal and neurodevelopmental outcomes. Design, Setting, and Participants This retrospective cohort study of preterm infants younger than 28 weeks gestational age born between January 1, 2006, and December 31, 2012, with clinical and echocardiography diagnoses of hemodynamically significant PDA was conducted at 3 tertiary neonatal intensive care units and affiliated follow-up programs. Exposure Surgical ligation vs medical management. Main Outcomes and Measures The primary outcome was a composite of death or neurodevelopmental impairment (NDI) at 18 to 24 months corrected age. Secondary outcomes included death before discharge, NDI, moderate-severe chronic lung disease, and severe retinopathy of prematurity. Multivariable logistic regression analysis was used to adjust for perinatal and postnatal confounders. Results Of 754 infants with hemodynamically significant PDA (mean [standard deviation] gestational age 25.7 [1.2] weeks and birth weight 813 [183] grams), 184 (24%) underwent ligation. Infants who underwent ligation had a higher frequency of morbidities before PDA closure, including sepsis, necrotizing enterocolitis, and a dependence on mechanical ventilation. After adjusting for perinatal characteristics and preligation morbidities, there was no difference in the odds of death or NDI (adjusted odds ratio (aOR), 0.83; 95% CI, 0.52-1.32), NDI (aOR, 1.27; 95% CI, 0.78-2.06), chronic lung disease (aOR, 1.36; 95% CI, 0.78-2.39) or severe retinopathy of prematurity (aOR, 1.61; 95% CI, 0.85-3.06). Ligation was associated with lower odds of mortality (aOR, 0.09; 95% CI, 0.04-0.21). Conclusions and Relevance Patent ductus arteriosus ligation among preterm neonates younger than 28 weeks gestational age was not associated with the composite outcome of death or NDI, and there were no differences in chronic lung disease, retinopathy of prematurity, or NDI among survivors. Mortality was lower among infants who underwent ligation, though residual survival bias could not be excluded. Previously reported associations of ligation with increased morbidity may be because of bias from confounding by indication. PMID:28264088

A comparative study of frictional force in self-ligating brackets according to the bracket-archwire angulation, bracket material, and wire type

PubMed Central

Lee, Souk Min

2015-01-01

Objective This study aimed to compare the frictional force (FR) in self-ligating brackets among different bracket-archwire angles, bracket materials, and archwire types. Methods Passive and active metal self-ligating brackets and active ceramic self-ligating brackets were included as experimental groups, while conventional twin metal brackets served as a control group. All brackets were maxillary premolar brackets with 0.022 inch [in] slots and a -7° torque. The orthodontic wires used included 0.018 round and 0.019 × 0.025 in rectangular stainless steel wires. The FR was measured at 0°, 5°, and 10° angulations as the wire was drawn through the bracket slots after attaching brackets from each group to the universal testing machine. Static and kinetic FRs were also measured. Results The passive self-ligating brackets generated a lower FR than all the other brackets. Static and kinetic FRs generally increased with an increase in the bracket-archwire angulation, and the rectangular wire caused significantly higher static and kinetic FRs than the round wire (p < 0.001). The metal passive self-ligating brackets exhibited the lowest static FR at the 0° angulation and a lower increase in static and kinetic FRs with an increase in bracket-archwire angulation than the other brackets, while the conventional twin brackets showed a greater increase than all three experimental brackets. Conclusions The passive self-ligating brackets showed the lowest FR in this study. Self-ligating brackets can generate varying FRs in vitro according to the wire size, surface characteristics, and bracket-archwire angulation. PMID:25667913

Exercise training prevents skeletal muscle damage in an experimental sepsis model

PubMed Central

Coelho, Carla Werlang; Jannig, Paulo R; de Souza, Arlete B; Fronza, Hercilio; Westphal, Glauco A; Petronilho, Fabricia; Constantino, Larissa; Dal-Pizzol, Felipe; Ferreira, Gabriela K; Streck, Emilio E; Silva, Eliezer

2013-01-01

OBJECTIVE: Oxidative stress plays an important role in skeletal muscle damage in sepsis. Aerobic exercise can decrease oxidative stress and enhance antioxidant defenses. Therefore, it was hypothesized that aerobic exercise training before a sepsis stimulus could attenuate skeletal muscle damage by modulating oxidative stress. Thus, the aim of this study was to evaluate the effects of aerobic physical preconditioning on the different mechanisms that are involved in sepsis-induced myopathy. METHODS: Male Wistar rats were randomly assigned to either the untrained or trained group. The exercise training protocol consisted of an eight-week treadmill program. After the training protocol, the animals from both groups were randomly assigned to either a sham group or a cecal ligation and perforation surgery group. Thus, the groups were as follows: sham, cecal ligation and perforation, sham trained, and cecal ligation and perforation trained. Five days after surgery, the animals were euthanized and their soleus and plantaris muscles were harvested. Fiber cross-sectional area, creatine kinase, thiobarbituric acid reactive species, carbonyl, catalase and superoxide dismutase activities were measured. RESULTS: The fiber cross-sectional area was smaller, and the creatine kinase, thiobarbituric acid reactive species and carbonyl levels were higher in both muscles in the cecal ligation and perforation group than in the sham and cecal ligation and perforation trained groups. The muscle superoxide dismutase activity was higher in the cecal ligation and perforation trained group than in the sham and cecal ligation and perforation groups. The muscle catalase activity was lower in the cecal ligation and perforation group than in the sham group. CONCLUSION: In summary, aerobic physical preconditioning prevents atrophy, lipid peroxidation and protein oxidation and improves superoxide dismutase activity in the skeletal muscles of septic rats. PMID:23420166

An enzyme-free flow cytometric bead assay for the sensitive detection of microRNAs based on click nucleic acid ligation-mediated signal amplification.

PubMed

Qi, Yan; Qiu, Liying; Fan, Wenjiao; Liu, Chenghui; Li, Zhengping

2017-08-07

A versatile flow cytometric bead assay (FCBA) coupled with a completely enzyme-free signal amplification mechanism is developed for the sensitive detection of microRNAs (miRNAs). This new strategy integrates click chemistry-mediated ligation chain reaction (CLCR) with hybridization chain reaction (HCR) for enzyme-free signal amplification on magnetic beads (MBs), and a flow cytometer for the robust fluorescence readout of the MBs. Firstly, target miRNA can initiate CLCR on the surface of MBs based on the click chemical ligation between dibenzocyclooctyne (DBCO)- and azide-modified single-stranded DNA (ssDNA) probes, and the amount of ligated ssDNA sequences on the MBs will be proportional to the dosage of target miRNA. Afterward, each of the ligated ssDNA products can trigger a cascade chain reaction of hybridization events between two alternating fluorophore-tagged hairpin probes, resulting in another signal amplification pathway with an amplified accumulation of fluorophores on the MBs. Finally, the fluorophore-anchored MBs are directly and rapidly analyzed by using a flow cytometer without any separation or elution processes. Herein, the click nucleic acid ligation only occurs on the surface of MBs, so the nonspecific ligations are greatly inhibited compared with that of ligation reaction performed in homogeneous solution. Furthermore, the signal amplification by CLCR-HCR is highly efficient but totally enzyme-free, which may overcome the potential drawbacks of conventional enzyme-catalyzed signal amplification protocols and lead to a high sensitivity. The CLCR-HCR-based FCBA has pushed the detection limit of let-7a miRNA down to the femtomolar (fM) level, showing great potential in miRNA-related biological studies and disease diagnosis.

Protein-Templated Fragment Ligations-From Molecular Recognition to Drug Discovery.

PubMed

Jaegle, Mike; Wong, Ee Lin; Tauber, Carolin; Nawrotzky, Eric; Arkona, Christoph; Rademann, Jörg

2017-06-19

Protein-templated fragment ligation is a novel concept to support drug discovery and can help to improve the efficacy of protein ligands. Protein-templated fragment ligations are chemical reactions between small molecules ("fragments") utilizing a protein's surface as a reaction vessel to catalyze the formation of a protein ligand with increased binding affinity. The approach exploits the molecular recognition of reactive small-molecule fragments by proteins both for ligand assembly and for the identification of bioactive fragment combinations. In this way, chemical synthesis and bioassay are integrated in one single step. This Review discusses the biophysical basis of reversible and irreversible fragment ligations and gives an overview of the available methods to detect protein-templated ligation products. The chemical scope and recent applications as well as future potential of the concept in drug discovery are reviewed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Significance of Reflux Abolition at the Saphenofemoral Junction in Connection with Stripping and Ablative Methods

PubMed Central

Recek, Cestmir

2015-01-01

Saphenous reflux interferes with the physiological decrease in pressure and induces ambulatory venous hypertension. Elimination of reflux is achieved by flush ligation at the incompetent saphenofemoral junction and stripping of the great saphenous vein, which is the basis of the conventional surgical therapy. Endovenous ablative methods substitute stripping by thermal of chemical destruction of the saphenous trunk; they usually refrain from saphenofemoral junction ligation. Short-term and medium-term results up to 5 years, achieved after endovenous ablation without high ligation, are comparable with those after conventional surgery, which questioned the necessity to ligate the incompetent saphenofemoral junction. Nevertheless, clinical symptoms caused by recurrent reflux occur as a rule not earlier than 8 to 10 years after efficient abolition of reflux. Consequently, randomized studies with long-term follow-ups exceeding 10 years are necessary for trustworthy assessment whether it is justified to abstain from saphenofemoral junction ligation. PMID:26648666

Decrease in oral bioavailability of ciclosporin by intravenous pulse of methylprednisolone succinate in rats.

PubMed

Konishi, Hiroki; Sumi, Masaki; Shibata, Nobuhito; Takada, Kanji; Minouchi, Tokuzo; Yamaji, Akira

2004-10-01

We examined the effects of high-dose methylprednisolone on the bioavailability of orally administered ciclosporin in rats. To emulate the clinical protocol of methylprednisolone pulse therapy, methylprednisolone sodium succinate (MPS), a prodrug of methylprednisolone, was intravenously administered as repeated doses (66.3 mg kg(-1)) for 3 days. The area under the blood ciclosporin concentration versus time curve after oral administration was significantly reduced by 60% by pulse treatment with MPS. Based on our previous finding that the total body clearance of ciclosporin was reduced by about 20% by the same methylprednisolone pulse protocol, the extent of reduction in the oral bioavailability of ciclosporin was estimated to be approximately 50%, indicating a drug interaction between high-dose methylprednisolone and orally administered ciclosporin, which affected the absorption process. In rats treated with MPS, an in-situ efflux experiment using rhodamine-123 demonstrated that the reverse transport function of P-glycoprotein (P-gp) in the small intestine was significantly enhanced, although there was no significant increase in the intestinal microsomal activity of triazolam alpha- and 4-hydroxylation, metabolic probes for CYP3A. In addition, a significant decrease was observed in the amount of secreted bile acids serving as an enhancer of gastrointestinal absorption of ciclosporin in MPS treatment. To directly estimate the absorptive capacity, an in-situ absorption test was conducted using a closed-loop of small intestine in control and MPS-treated rats. Intestinal absorption of ciclosporin was significantly decreased, not only in the absence of bile flow but also by treatment with MPS, which well reflected the change in the in-vivo pharmacokinetic behaviour of ciclosporin after methylprednisolone pulsing. These results demonstrate that bioavailability of ciclosporin is markedly reduced by MPS pulse treatment, and the mechanism of this interaction was confirmed to involve enhancement of small-intestinal P-gp function and decrease in bile secretion.

A high-throughput assay for the comprehensive profiling of DNA ligase fidelity

PubMed Central

Lohman, Gregory J. S.; Bauer, Robert J.; Nichols, Nicole M.; Mazzola, Laurie; Bybee, Joanna; Rivizzigno, Danielle; Cantin, Elizabeth; Evans, Thomas C.

2016-01-01

DNA ligases have broad application in molecular biology, from traditional cloning methods to modern synthetic biology and molecular diagnostics protocols. Ligation-based detection of polynucleotide sequences can be achieved by the ligation of probe oligonucleotides when annealed to a complementary target sequence. In order to achieve a high sensitivity and low background, the ligase must efficiently join correctly base-paired substrates, while discriminating against the ligation of substrates containing even one mismatched base pair. In the current study, we report the use of capillary electrophoresis to rapidly generate mismatch fidelity profiles that interrogate all 256 possible base-pair combinations at a ligation junction in a single experiment. Rapid screening of ligase fidelity in a 96-well plate format has allowed the study of ligase fidelity in unprecedented depth. As an example of this new method, herein we report the ligation fidelity of Thermus thermophilus DNA ligase at a range of temperatures, buffer pH and monovalent cation strength. This screen allows the selection of reaction conditions that maximize fidelity without sacrificing activity, while generating a profile of specific mismatches that ligate detectably under each set of conditions. PMID:26365241

A high-throughput assay for the comprehensive profiling of DNA ligase fidelity.

PubMed

Lohman, Gregory J S; Bauer, Robert J; Nichols, Nicole M; Mazzola, Laurie; Bybee, Joanna; Rivizzigno, Danielle; Cantin, Elizabeth; Evans, Thomas C

2016-01-29

DNA ligases have broad application in molecular biology, from traditional cloning methods to modern synthetic biology and molecular diagnostics protocols. Ligation-based detection of polynucleotide sequences can be achieved by the ligation of probe oligonucleotides when annealed to a complementary target sequence. In order to achieve a high sensitivity and low background, the ligase must efficiently join correctly base-paired substrates, while discriminating against the ligation of substrates containing even one mismatched base pair. In the current study, we report the use of capillary electrophoresis to rapidly generate mismatch fidelity profiles that interrogate all 256 possible base-pair combinations at a ligation junction in a single experiment. Rapid screening of ligase fidelity in a 96-well plate format has allowed the study of ligase fidelity in unprecedented depth. As an example of this new method, herein we report the ligation fidelity of Thermus thermophilus DNA ligase at a range of temperatures, buffer pH and monovalent cation strength. This screen allows the selection of reaction conditions that maximize fidelity without sacrificing activity, while generating a profile of specific mismatches that ligate detectably under each set of conditions. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Haemodynamic effects of a selective adenosine A2A receptor agonist, CGS 21680, in chronic heart failure in anaesthetized rats

PubMed Central

Nekooeian, Ali A; Tabrizchi, Reza

1998-01-01

Recently we demonstrated that the administration of an A2A adenosine receptor agonist, CGS 21680, to anaesthetized rats with acute heart failure (1 h post-coronary artery ligation) resulted in an increase in cardiac output. In the present investigation, the effects of CGS 21680 on cardiac output, vascular resistance, heart rate, blood pressure and mean circulatory filling pressure (Pmcf) were investigated in anaesthetized rats with chronic heart failure (8 weeks post-coronary artery ligation).Experiments were conducted in five groups (n=6) of animals: sham-operated vehicle-treated (0.9% NaCl; 0.037 mL kg−1 min−1) animals in which the occluder was placed but not pulled to ligate the coronary artery; coronary artery-ligated vehicle-treated animals; and coronary artery-ligated CGS 21680-treated (0.1, 0.3 or 1.0 μg kg−1 min−1) animals.Baseline blood pressure, cardiac output and rate of rise in left ventricular pressure (+dP/dt) were significantly reduced in animals with coronary artery ligation when compared to sham-operated animals. Coronary artery ligation resulted in a significant increase in left ventricular end-diastolic pressure, Pmcf and venous resistance when compared to sham-operated animals.Administration of CGS 21680 at 0.3 and 1.0 μg kg−1 min−1 significantly (n=6; P<0.05) increased cardiac output by 19±4% and 39±5%, and heart rate by 14±2% and 15±1%, respectively, when compared to vehicle treatment in coronary artery-ligated animals. Administration of CGS 21680 also significantly reduced blood pressure and arterial resistance when compared to coronary artery-ligated vehicle-treated animals. Infusion of CGS 21680 also significantly reduced venous resistance when compared to vehicle-treated coronary artery-ligated animals.The results show that heart failure is characterized by reduced cardiac output, and increased left ventricular end-diastolic pressure, venous resistance and Pmcf. Acute treatment with CGS 21680 in animals with chronic heart failure decreased left ventricular end-diastolic pressure and increased cardiac output. This increase in cardiac output was the result of reduced arterial and venous resistances and increased heart rate. PMID:9831898

Effects of double ligation of Stensen's duct on the rabbit parotid gland.

PubMed

Maria, O M; Maria, S M; Redman, R S; Maria, A M; Saad El-Din, T A; Soussa, E F; Tran, S D

2014-04-01

Salivary gland duct ligation is an alternative to gland excision for treating sialorrhea or reducing salivary gland size prior to tumor excision. Duct ligation also is used as an approach to study salivary gland aging, regeneration, radiotherapy, sialolithiasis and sialadenitis. Reports conflict about the contribution of each salivary cell population to gland size reduction after ductal ligation. Certain cell populations, especially acini, reportedly undergo atrophy, apoptosis and proliferation during reduction of gland size. Acini also have been reported to de-differentiate into ducts. These contradictory results have been attributed to different animal or salivary gland models, or to methods of ligation. We report here a bilateral double ligature technique for rabbit parotid glands with histologic observations at 1, 7, 14, 30, 60 days after ligation. A large battery of special stains and immunohistochemical procedures was employed to define the cell populations. Four stages with overlapping features were observed that led to progressive shutdown of gland activities: 1) marked atrophy of the acinar cells occurred by 14 days, 2) response to and removal of the secretory material trapped in the acinar and ductal lumens mainly between 30 and 60 days, 3) reduction in the number of parenchymal (mostly acinar) cells by apoptosis that occurred mainly between 14-30 days, and 4) maintenance of steady-state at 60 days with a low rate of fluid, protein, and glycoprotein secretion, which greatly decreased the number of leukocytes engaged in the removal of the luminal contents. The main post- ligation characteristics were dilation of ductal and acinar lumens, massive transient infiltration of mostly heterophils (rabbit polymorphonuclear leukocytes), acinar atrophy, and apoptosis of both acinar and ductal cells. Proliferation was uncommon except in the larger ducts. By 30 days, the distribution of myoepithelial cells had spread from exclusively investing the intercalated ducts pre-ligation to surrounding a majority of the residual duct-like structures, many of which clearly were atrophic acini. Thus, both atrophy and apoptosis made major contributions to the post-ligation reduction in gland size. Structures also occurred with both ductal and acinar markers that suggested acini differentiating into ducts. Overall, the reaction to duct ligation proceeded at a considerably slower pace in the rabbit parotid glands than has been reported for the salivary glands of the rat.

Iron dysregulation combined with aging prevents sepsis-induced apoptosis

PubMed Central

Javadi, Pardis; Buchman, Timothy G.; Stromberg, Paul E.; Turnbull, Isaiah R.; Vyas, Dinesh; Hotchkiss, Richard S.; Karl, Irene E.; Coopersmith, Craig M.

2005-01-01

Background Sepsis, iron loading and aging cause independent increases in gut epithelial and splenic apoptosis. It is unknown how their combination will affect apoptosis and systemic cytokine levels. Methods Hfe−/− mice (a murine homolog of hemochromatosis) abnormally accumulate iron in their tissues. Aged (24–26 months) or mature (16–18 months) Hfe−/− mice and wild type (WT) littermates were subjected to cecal ligation and puncture (CLP) or sham laparotomy. Intestine, spleen, and blood were harvested 24 hours later and assessed for apoptosis and cytokine levels. Results Gut epithelial and splenic apoptosis were low in both aged septic and sham Hfe−/− mice, regardless of the amount of iron in their diet. Mature septic WT mice had increased apoptosis compared to age-matched sham WT mice. Mature septic Hfe−/− mice had similar levels of intestinal cell death to age-matched septic WT mice but higher levels of splenic apoptosis. Apoptosis was significantly lower in septic aged Hfe−/− mice than septic mature Hfe−/− animals. Interleukin-6 was elevated in septic aged Hfe−/− mice compared to sham mice. Conclusions Although sepsis, chronic iron dysregulation, and aging each increase gut and splenic apoptosis, their combination yields cell death levels similar to sham animals despite the fact that aged Hfe−/− mice are able to mount an inflammatory response following CLP and mature Hfe−/− mice have elevated sepsis-induced apoptosis. Combining sepsis with two risk factors that ordinarily increase cell death and increase mortality in CLP yields an apoptotic response that could not have been predicted based upon each element in isolation. PMID:15921699

Sepsis reveals compartment-specific responses in intestinal proliferation and apoptosis in transgenic mice whose enterocytes re-enter the cell cycle.

PubMed

Lyons, John D; Klingensmith, Nathan J; Otani, Shunsuke; Mittal, Rohit; Liang, Zhe; Ford, Mandy L; Coopersmith, Craig M

2017-12-01

Cell production and death are tightly regulated in the rapidly renewing gut epithelium, with proliferation confined to crypts and apoptosis occurring in villi and crypts. This study sought to determine how stress alters these compartmentalized processes. Wild-type mice made septic via cecal ligation and puncture had decreased crypt proliferation and increased crypt and villus apoptosis. Fabpi -TAg mice expressing large T-antigen solely in villi had ectopic enterocyte proliferation with increased villus apoptosis in unmanipulated animals. Septic fabpi -TAg mice had an unexpected increase in villus proliferation compared with unmanipulated littermates, whereas crypt proliferation was decreased. Cell cycle regulators cyclin D1 and cyclin D2 were decreased in jejunal tissue in septic transgenic mice. In contrast, villus and crypt apoptosis were increased in septic fabpi -TAg mice. To examine the relationship between apoptosis and proliferation in a compartment-specific manner, fabpi -TAg mice were crossed with fabpl -Bcl-2 mice, resulting in expression of both genes in the villus but Bcl-2 alone in the crypt. Septic bi-transgenic animals had decreased crypt apoptosis but had a paradoxical increase in villus apoptosis compared with septic fabpi -TAg mice, associated with decreased proliferation in both compartments. Thus, sepsis unmasks compartment-specific proliferative and apoptotic regulation that is not present under homeostatic conditions.-Lyons, J. D., Klingensmith, N. J., Otani, S., Mittal, R., Liang, Z., Ford, M. L., Coopersmith, C. M. Sepsis reveals compartment-specific responses in intestinal proliferation and apoptosis in transgenic mice whose enterocytes re-enter the cell cycle. © FASEB.

Severity and treatment of "occult" intra-abdominal injuries in blunt trauma victims.

PubMed

Parreira, José G; Oliari, Camilla B; Malpaga, Juliano M D; Perlingeiro, Jacqueline A G; Soldá, Silvia C; Assef, José C

2016-01-01

to assess the severity and treatment of "occult" intra-abdominal injuries in blunt trauma victims. Retrospective analysis of charts and trauma register data of adult blunt trauma victims, admitted without abdominal pain or alterations in the abdominal physical examination, but were subsequently diagnosed with intra-abdominal injuries, in a period of 2 years. The severity was stratified according to RTS, AIS, OIS and ISS. The specific treatment for abdominal injuries and the complications related to them were assessed. Intra-abdominal injuries were diagnosed in 220 (3.8%) out of the 5785 blunt trauma victims and 76 (34.5%) met the inclusion criteria. The RTS and ISS median (lower quartile, upper quartile) were 7.84 (6.05, 7.84) and 25 (16, 34). Sixty seven percent had a GCS≥13 on admission. Injuries were identified in the spleen (34), liver (33), kidneys (9), intestines (4), diaphragm (3), bladder (3) and iliac vessels (1). Abdominal injuries scored AIS≥3 in 67% of patients. Twenty-one patients (28%) underwent laparotomy, 5 of which were nontherapeutic. The surgical procedures performed were splenectomy (8), suturing of the diaphragm (3), intestines (3), bladder (2), kidneys (1), enterectomy/anastomosis (1), ligation of the common iliac vein (1), and revascularization of the common iliac artery (1). Angiography and embolization of liver and/or spleen injuries were performed in 3 cases. Three patients developed abdominal complications, all of which were operatively treated. There were no deaths directly related to the abdominal injuries. Severe "occult" intra-abdominal injuries, requiring specific treatment, may be present in adult blunt trauma patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

Intestinal decontamination inhibits TLR4 dependent fibronectin mediated crosstalk between stellate cells and endothelial cells in liver fibrosis in mice

PubMed Central

Zhu, Qiang; Zou, Li; Jagavelu, Kumaravelu; Simonetto, Douglas A.; Huebert, Robert C.; Jiang, Zhi-Dong; DuPont, Herbert L.; Shah, Vijay H.

2012-01-01

Background/Aims Liver fibrosis is associated with angiogenesis and leads to portal hypertension. Certain antibiotics reduce complications of liver failure in humans, however, effect of antibiotics on the pathologic alterations of the disease are not fully understood. The aim of this study was to test whether the non-absorbable antibiotic rifaximin could attenuate fibrosis progression and portal hypertension in vivo, and explore potential mechanisms in vitro. Methods Effect of rifaximin on portal pressure, fibrosis, and angiogenesis was examined in wild type and toll like receptor 4 (TLR4) mutant mice after bile duct ligation (BDL). In vitro studies were carried out to evaluate the effect of the bacterial product and TLR agonist, lipopolysaccharide (LPS) on paracrine interactions between hepatic stellate cells (HSC) and liver endothelial cells (LEC) that lead to fibrosis and portal hypertension. Results Portal pressure, fibrosis, and angiogenesis were significantly lower in BDL mice receiving rifaximin compared to BDL mice receiving vehicle. Studies in TLR4 mutant mice confirmed that the effect of rifaximin was dependent on LPS/TLR4 pathway. Fibronectin (FN) was increased in BDL liver and was reduced by rifaximin administration and thus was explored further in vitro as a potential mediator of paracrine interactions of HSC and LEC. In vitro, LPS promoted FN production from HSC. Furthermore, HSC-derived FN promoted LEC migration and angiogenesis. Conclusion These studies expand our understanding of the relationship of intestinal microbiota with fibrosis development by identifying FN as a TLR4 dependent mediator of the matrix and vascular changes that characterize cirrhosis. PMID:22173161

The Superoxide Reductase from the Early Diverging Eukaryote Giardia Intestinalis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cabelli, D.E.; Testa, F.; Mastronicola, D.

2011-10-15

Unlike superoxide dismutases (SODs), superoxidereductases (SORs) eliminate superoxide anion (O{sub 2}{sup {sm_bullet}-}) not through its dismutation, but via reduction to hydrogen peroxide (H{sub 2}O{sub 2}) in the presence of an electron donor. The microaerobic protist Giardia intestinalis, responsible for a common intestinal disease in humans, though lacking SOD and other canonical reactive oxygen species-detoxifying systems, is among the very few eukaryotes encoding a SOR yet identified. In this study, the recombinant SOR from Giardia (SOR{sub Gi}) was purified and characterized by pulse radiolysis and stopped-flow spectrophotometry. The protein, isolated in the reduced state, after oxidation by superoxide or hexachloroiridate(IV), yieldsmore » a resting species (T{sub final}) with Fe{sup 3+} ligated to glutamate or hydroxide depending on pH (apparent pK{sub a} = 8.7). Although showing negligible SOD activity, reduced SOR{sub Gi} reacts with O{sub 2}{sup {sm_bullet}-} with a pH-independent second-order rate constant k{sub 1} = 1.0 x 10{sup 9} M{sup -1} s{sup -1} and yields the ferric-(hydro)peroxo intermediate T{sub 1}; this in turn rapidly decays to the T{sub final} state with pH-dependent rates, without populating other detectable intermediates. Immunoblotting assays show that SOR{sub Gi} is expressed in the disease-causing trophozoite of Giardia. We propose that the superoxide-scavenging activity of SOR in Giardia may promote the survival of this air-sensitive parasite in the fairly aerobic proximal human small intestine during infection.« less

Drug gastrointestinal absorption in rat: Strain and gender differences.

PubMed

Oltra-Noguera, Davinia; Mangas-Sanjuan, Victor; González-Álvarez, Isabel; Colon-Useche, Sarin; González-Álvarez, Marta; Bermejo, Marival

2015-10-12

Predictive animal models of intestinal drug absorption are essential tools in drug development to identify compounds with promising biopharmaceutical properties. In situ perfusion absorption studies are routinely used in the preclinical setting to screen drug candidates. The objective of this work is to explore the differences in magnitude and variability on intestinal absorption associated with rat strain and gender. Metoprolol and Verapamil absorption rate coefficients were determined using the in situ closed loop perfusion model in four strains of rats and in both genders. Strains used were Sprague-Dawley, Wistar-Han, Wistar-Unilever, Long-Evans and CD∗IGS. In the case of Metoprolol only CD∗IGS and Wistar Unilever showed differences between males and females. For Verapamil, Wistar Han and Sprague-Dawley strains do not show differences between male and female rats. That means that in these strains permeability data from male and female could be combined. In male rats, which are commonly used for permeability estimation, there were differences for Metoprolol permeability between Sprague-Dawley (with lower permeability values) and the other strains, while for Verapamil Sprague-Dawley and Wistar-Han showed the lower permeability values. In conclusion, the selection of rat's strain and gender for intestinal absorption experiments is a relevant element during study design and data from different strains may not be always comparable. Copyright © 2015 Elsevier B.V. All rights reserved.

Changes in intestinal fluid and mucosal immune responses to cholera toxin in Giardia muris infection and binding of cholera toxin to Giardia muris trophozoites.

PubMed

Ljungström, I; Holmgren, J; Svennerholm, A M; Ferrante, A

1985-10-01

The effect of Giardia muris infection on the diarrheal response and gut mucosal antibody response to cholera toxin was examined in mice. The results obtained showed that the fluid accumulation in intestinal loops exposed to cholera toxin was increased in mice infected with a low number (5 X 10(4) ) of G. muris cysts compared with the response in noninfected mice. This effect was associated with a marked reduction in absorption of oral rehydration fluid from the intestine. In contrast, mice infected with a high dose (2 X 10(5) ) of cysts showed a marked decrease in fluid accumulation in response to the toxin. This decrease might be related to the finding that both G. muris and Giardia lamblia trophozoites can bind significant amounts of cholera toxin. Evidence is presented which suggests that the gut mucosal antibody response, mainly immunoglobulin A but also immunoglobulin G, to an immunization course with perorally administered cholera toxin was depressed in mice infected with G. muris. The reduction in antibody levels was particularly evident when the primary immunization was made very early after infection. The serum antitoxin antibodies to the oral immunization with cholera toxin were, however, not affected. Likewise, the delayed-type hypersensitivity response against sheep erythrocytes in animals primed subcutaneously with sheep erythrocytes was not modified during the course of G. muris infection.

Time course of collagen peak in bile duct-ligated rats.

PubMed

Tarcin, Orhan; Basaranoglu, Metin; Tahan, Veysel; Tahan, Gülgün; Sücüllü, Ilker; Yilmaz, Nevin; Sood, Gagan; Snyder, Ned; Hilman, Gilbert; Celikel, Cigdem; Tözün, Nurdan

2011-04-28

One of the most useful experimental fibrogenesis models is the "bile duct-ligated rats". Our aim was to investigate the quantitative hepatic collagen content by two different methods during the different stages of hepatic fibrosis in bile duct-ligated rats on a weekly basis. We questioned whether the 1-wk or 4-wk bile duct-ligated model is suitable in animal fibrogenesis trials. Of the 53 male Wistar rats, 8 (Group 0) were used as a healthy control group. Bile duct ligation (BDL) had been performed in the rest. Bile duct-ligated rates were sacrificed 7 days later in group 1 (10 rats), 14 days later in group 2 (9 rats), 21 days later in group 3(9 rats) and 28 days later in group 4 (9 rats). Eight rats underwent sham-operation (Sham). Hepatic collagen measurements as well as serum levels of liver enzymes and function tests were all analysed. The peak level of collagen was observed biochemically and histomorphometricly at the end of third week (P < 0.001 and P < 0.05). Suprisingly, collagen levels had decreased with the course of time such as at the end of fourth week (P < 0.01 and P < 0.05). We have shown that fibrosis in bile duct-ligated rats is transient, i.e. reverses spontaneously after 3 weeks. This contrasts any situation in patients where hepatic fibrosis is progressive and irreversible as countless studies performed by many investigators in the same animal model.

Ligation with Nucleic Acid Sequence–Based Amplification

PubMed Central

Ong, Carmichael; Tai, Warren; Sarma, Aartik; Opal, Steven M.; Artenstein, Andrew W.; Tripathi, Anubhav

2012-01-01

This work presents a novel method for detecting nucleic acid targets using a ligation step along with an isothermal, exponential amplification step. We use an engineered ssDNA with two variable regions on the ends, allowing us to design the probe for optimal reaction kinetics and primer binding. This two-part probe is ligated by T4 DNA Ligase only when both parts bind adjacently to the target. The assay demonstrates that the expected 72-nt RNA product appears only when the synthetic target, T4 ligase, and both probe fragments are present during the ligation step. An extraneous 38-nt RNA product also appears due to linear amplification of unligated probe (P3), but its presence does not cause a false-positive result. In addition, 40 mmol/L KCl in the final amplification mix was found to be optimal. It was also found that increasing P5 in excess of P3 helped with ligation and reduced the extraneous 38-nt RNA product. The assay was also tested with a single nucleotide polymorphism target, changing one base at the ligation site. The assay was able to yield a negative signal despite only a single-base change. Finally, using P3 and P5 with longer binding sites results in increased overall sensitivity of the reaction, showing that increasing ligation efficiency can improve the assay overall. We believe that this method can be used effectively for a number of diagnostic assays. PMID:22449695

Frictional resistance of self-ligating versus conventional brackets in different bracket-archwire-angle combinations

PubMed Central

MONTEIRO, Maria Regina Guerra; da SILVA, Licinio Esmeraldo; ELIAS, Carlos Nelson; VILELLA, Oswaldo de Vasconcellos

2014-01-01

Objective To compare the influence of archwire material (NiTi, beta-Ti and stainless steel) and brackets design (self-ligating and conventional) on the frictional force resistance. Material and Methods Two types of brackets (self-ligating brackets - Smartclip, 3M/Unitek - and conventional brackets - Gemini, 3M/Unitek) with three (0, 5, and 10 degrees) slot angulation attached with elastomeric ligatures (TP Orthodontics) were tested. All brackets were tested with archwire 0.019"x0.025" nickel-titanium, beta-titanium, and stainless steel (Unitek/3M). The mechanical testing was performed with a universal testing machine eMIC DL 10000 (eMIC Co, Brazil). The wires were pulled from the bracket slots at a cross-head speed of 3 mm/min until 2 mm displacement. Results Self-ligating brackets produced significantly lower friction values compared with those of conventional brackets. Frictional force resistance values were directly proportional to the increase in the bracket/ wire angulation. With regard to conventional brackets, stainless steel wires had the lowest friction force values, followed by nickel-titanium and beta-titanium ones. With regard to self-ligating brackets, the nickel-titanium wires had the lowest friction values, significantly lower than those of other materials. Conclusion even at different angulations, the self-ligating brackets showed significantly lower friction force values than the conventional brackets. Combined with nickel-titanium wires, the self-ligating brackets exhibit much lower friction, possibly due to the contact between nickel-titanium clips and wires of the same material. PMID:25025564

Self-ligating versus conventional metallic brackets on Streptococcus mutans retention: A systematic review

PubMed Central

Longoni, Juliano N.; Lopes, Beatriz M.; Freires, Irlan A.; Dutra, Kamile L.; Franco, Ademir; Paranhos, Luiz R.

2017-01-01

Objective: The present study aimed to review the literature systematically and assess comparatively whether self-ligating metallic brackets accumulate less Streptococcus mutans biofilm than conventional metallic brackets. Material and methods: The systematic search was performed following PRISMA guidelines and registration in PROSPERO. Seven electronic databases (Google Scholar, LILACS, Open Grey, PubMed, SciELO, ScienceDirect, and Scopus) were consulted until April 2016, with no restriction of language and time of publication. Only randomized clinical studies verifying S. mutans colonization in metallic brackets (self-ligating and conventional) were included. All steps were performed independently by two operators. Results: The search resulted in 546 records obtained from the electronic databases. Additionally, 216 references obtained from the manual search of eligible articles were assessed. Finally, a total of 5 studies were included in the qualitative synthesis. In 1 study, the total bacterial count was not different among self-ligating and conventional brackets, whereas in 2 studies the amount was lower for self-ligating brackets. Regarding the specific count of S. mutans, 2 studies showed less accumulation in self-ligating than in conventional brackets. Conclusion: Based on the limited evidence, self-ligating metallic brackets accumulate less S. mutans than conventional ones. However, these findings must be interpreted in conjunction with particularities individual for each patient – such as hygiene and dietary habits, which are components of the multifactorial environment that enables S. Mutans to proliferate and keep retained in the oral cavity. PMID:29279684

Prolonged exposure to 1,25(OH)2D3 and high ionized calcium induces FGF-23 production in intestinal epithelium-like Caco-2 monolayer: A local negative feedback for preventing excessive calcium transport.

PubMed

Rodrat, Mayuree; Wongdee, Kannikar; Panupinthu, Nattapon; Thongbunchoo, Jirawan; Teerapornpuntakit, Jarinthorn; Krishnamra, Nateetip; Charoenphandhu, Narattaphol

2018-02-15

Overdose of oral calcium supplement and excessive intestinal calcium absorption can contribute pathophysiological conditions, e.g., nephrolithiasis, vascular calcification, dementia, and cardiovascular accident. Since our previous investigation has indicated that fibroblast growth factor (FGF)-23 could abolish the 1,25-dihydroxyvitamin D 3 [1,25(OH) 2 D 3 ]-enhanced calcium absorption, we further hypothesized that FGF-23 produced locally in the enterocytes might be part of a local negative feedback loop to regulate calcium absorption. Herein, 1,25(OH) 2 D 3 was found to enhance the transcellular calcium transport across the epithelium-like Caco-2 monolayer, and this stimulatory effect was diminished by preceding prolonged exposure to high-dose 1,25(OH) 2 D 3 or high concentration of apical ionized calcium. Pretreatment with a neutralizing antibody for FGF-23 prevented this negative feedback regulation of calcium hyperabsorption induced by 1,25(OH) 2 D 3 . FGF-23 exposure completely abolished the 1,25(OH) 2 D 3 -enhanced calcium transport. Western blot analysis revealed that FGF-23 expression was upregulated in a dose-dependent manner by 1,25(OH) 2 D 3 or apical calcium exposure. Finally, calcium-sensing receptor (CaSR) inhibitors were found to prevent the apical calcium-induced suppression of calcium transport. In conclusion, prolonged exposure to high apical calcium and calcium hyperabsorption were sensed by CaSR, which, in turn, increased FGF-23 expression to suppress calcium transport. This local negative feedback loop can help prevent unnecessary calcium uptake and its detrimental consequences. Copyright © 2018 Elsevier Inc. All rights reserved.

Intestinal alkaline phosphatase regulates protective surface microclimate pH in rat duodenum.

PubMed

Mizumori, Misa; Ham, Maggie; Guth, Paul H; Engel, Eli; Kaunitz, Jonathan D; Akiba, Yasutada

2009-07-15

Regulation of localized extracellular pH (pH(o)) maintains normal organ function. An alkaline microclimate overlying the duodenal enterocyte brush border protects the mucosa from luminal acid. We hypothesized that intestinal alkaline phosphatase (IAP) regulates pH(o) due to pH-sensitive ATP hydrolysis as part of an ecto-purinergic pH regulatory system, comprised of cell-surface P2Y receptors and ATP-stimulated duodenal bicarbonate secretion (DBS). To test this hypothesis, we measured DBS in a perfused rat duodenal loop, examining the effect of the competitive alkaline phosphatase inhibitor glycerol phosphate (GP), the ecto-nucleoside triphosphate diphosphohydrolase inhibitor ARL67156, and exogenous nucleotides or P2 receptor agonists on DBS. Furthermore, we measured perfusate ATP concentration with a luciferin-luciferase bioassay. IAP inhibition increased DBS and luminal ATP output. Increased luminal ATP output was partially CFTR dependent, but was not due to cellular injury. Immunofluorescence localized the P2Y(1) receptor to the brush border membrane of duodenal villi. The P2Y(1) agonist 2-methylthio-ADP increased DBS, whereas the P2Y(1) antagonist MRS2179 reduced ATP- or GP-induced DBS. Acid perfusion augmented DBS and ATP release, further enhanced by the IAP inhibitor l-cysteine, and reduced by the exogenous ATPase apyrase. Furthermore, MRS2179 or the highly selective P2Y(1) antagonist MRS2500 co-perfused with acid induced epithelial injury, suggesting that IAP/ATP/P2Y signalling protects the mucosa from acid injury. Increased DBS augments IAP activity presumably by raising pH(o), increasing the rate of ATP degradation, decreasing ATP-mediated DBS, forming a negative feedback loop. The duodenal epithelial brush border IAP-P2Y-HCO(3-) surface microclimate pH regulatory system effectively protects the mucosa from acid injury.

Furosemide suppresses ileal and colonic contractility via interactions with GABA-A receptor in mice.

PubMed

Kaewsaro, Kannaree; Nualplub, Suparp; Bumrungsri, Sara; Khuituan, Pissared

2017-11-01

The loop diuretic furosemide has an action to inhibit Na + -K + -2Cl - co-transporter at the thick ascending limb of Henle's loop resulting in diuresis. Furosemide also has the non-diuretic effects by binding to GABA-A receptor which may involve the gastrointestinal tract. The aim of this study was to investigate the effects of furosemide on smooth muscle contractions in mice ileum and proximal colon. Each intestinal segment suspended in an organ bath was connected to a force transducer. Signal output of mechanical activity was amplified and recorded for analysis using PowerLab System. After equilibration, the intestine was directly exposed to furosemide, GABA, GABA-A receptor agonist (muscimol), or muscarinic receptor antagonist (atropine). Furosemide (50, 100 and 500 μmol L -1 ) acutely reduced the amplitude of ileal and colonic contraction. In the ileum, 1 mmol L -1 GABA and 10-60 μmol L -1 muscimol significantly increased the amplitude, whereas in the colon, 50-100 mmol L -1 GABA and 60 μmol L -1 muscimol decreased the contractions. The contractions were also significantly suppressed by atropine. To investigate the mechanisms underlying the inhibiting effect of furosemide, furosemide was added to the organ bath prior to the addition of muscimol or atropine. A comparison of furosemide combined with muscimol or atropine group and furosemide group showed no significant difference of the ileal contraction, but the amplitude of colonic contraction significantly decreased when compared to adding furosemide alone. These results suggest that furosemide can reduce the ileal and proximal colonic contraction mediated by blocking and supporting of GABA-A receptor, respectively, resulting in decreased acetylcholine release. © 2017 John Wiley & Sons Australia, Ltd.

A novel pathway down-modulating T cell activation involves HPK-1-dependent recruitment of 14-3-3 proteins on SLP-76.

PubMed

Di Bartolo, Vincenzo; Montagne, Benjamin; Salek, Mogjiborahman; Jungwirth, Britta; Carrette, Florent; Fourtane, Julien; Sol-Foulon, Nathalie; Michel, Frédérique; Schwartz, Olivier; Lehmann, Wolf D; Acuto, Oreste

2007-03-19

The SH2 domain-containing leukocyte protein of 76 kD (SLP-76) is a pivotal element of the signaling machinery controlling T cell receptor (TCR)-mediated activation. Here, we identify 14-3-3epsilon and zeta proteins as SLP-76 binding partners. This interaction was induced by TCR ligation and required phosphorylation of SLP-76 at serine 376. Ribonucleic acid interference and in vitro phosphorylation experiments showed that serine 376 is the target of the hematopoietic progenitor kinase 1 (HPK-1). Interestingly, either S376A mutation or HPK-1 knockdown resulted in increased TCR-induced tyrosine phosphorylation of SLP-76 and phospholipase C-gamma1. Moreover, an SLP-76-S376A mutant induced higher interleukin 2 gene transcription than wild-type SLP-76. These data reveal a novel negative feedback loop involving HPK-1-dependent serine phosphorylation of SLP-76 and 14-3-3 protein recruitment, which tunes T cell activation.

Rejection of isolated pancreatic allografts in patients with with diabetes.

PubMed

Groth, C G; Lundgren, G; Arner, P; Collste, H; Hårdstedt, C; Lewander, R; Ostman, J

1976-12-01

Four patients with diabetes mellitus of juvenile onset but without uremia have been treated with segmental transplantation of the body and tail of pancreas. The indications were hyperlabile diabetes or progressive loss of vision. The grafts were procured from cadaveric donors four to 16 minutes after circulary arrest and were subsequently stored in the cold for approximately four hours. In one patient, the pancreatic duct was ligated, while in the other three, drainage was attained by suturing the transected end of the pancreas into a jejunal Roux-en-Y loop. Three of the grafts failed within six weeks as a result of irreversible refection, and one graft failed because of the early onset of venous thrombosis. The first sign of graft rejection was an increase in the postprandial blood sugar level, an increase in the fasting blood sugar level occurring several days later. Neither hyperamylasemia nor fever was observed. Radioisotope scans and angiograms were of great value in establishing the diagnosis of graft rejection. All of the patients survived after graft removal.

Modified protrusion arch for anterior crossbite correction - a case report.

PubMed

Roy, Abhishek Singha; Singh, Gulshan Kr; Tandon, Pradeep; Chaudhary, Ramsukh

2013-01-01

Borderline and mild skeletal Class III relationships in adult patients are usually treated by orthodontic camouflage. Reasonably rood results have been achieved with nonsurgical teatment of anterior crossbite. Class III malocclusion may be associated with mandibular prognathism, maxillary retrognathism, or both. Class III maxillary retrognathism generally involves anterior crossbite, which must be opened if upper labial brackets are to be bonded. If multiple teeth are in crossbite, after opening the bite usual step is to ligate forward or advancement arch made of 0.018" or 0.020" stainless steel or NiTi wire main arch that must be kept separated 2 mm from the slot ofupper incisor braces. Two stops or omegas are made 1 mm mesial to the tubes of the molar bands that will impede main arch from slipping,and in this manner the arch will push the anterior teeth forward Here we have fabricated a modified multiple loop protrusion arch to correct an anterior crossbite with severe crowding that was not amenable to correct by advancement arches.

Single-nucleus Hi-C of mammalian oocytes and zygotes.

PubMed

Gassler, Johanna; Flyamer, Ilya M; Tachibana, Kikuë

2018-01-01

The 3D folding of the genome is linked to essential nuclear processes including gene expression, DNA repair, and replication. Chromatin conformation capture assays such as Hi-C are providing unprecedented insights into higher-order chromatin structure. Bulk Hi-C of millions of cells enables detection of average chromatin features at high resolution but is challenging to apply to rare cell types. This chapter describes our recently developed single-nucleus Hi-C (snHi-C) approach for detection of chromatin contacts in single nuclei of murine oocytes and one-cell embryos (zygotes). The step-by-step protocol includes isolation of these cells, extraction of nuclei, fixation, restriction digestion, ligation, and whole genome amplification. Contacts obtained by snHi-C allow detection of chromatin features including loops, topologically associating domains, and compartments when averaged over the genome. The combination of snHi-C with other single-cell techniques in these and other rare cell types will likely provide a comprehensive picture of how chromatin architecture shapes cell identity. © 2018 Elsevier Inc. All rights reserved.

Adherence of Escherichia coli O157:H7 to epithelial cells in vitro and in pig gut loops is affected by bacterial culture conditions

PubMed Central

Yin, Xianhua; Feng, Yanni; Wheatcroft, Roger; Chambers, James; Gong, Joshua; Gyles, Carlton L.

2011-01-01

The objectives of this study were to determine the effect of bacterial culture conditions on adherence of enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain 86-24 in vivo to pig enterocytes and to compare the results with adherence in vitro to cultured HEp-2 and IPEC-J2 cells. Growth of O157:H7 in MacConkey broth (MB) resulted in almost no adherence to both HEp-2 and IPEC-J2 cells; prior exposure of the bacteria to pH 2.5 reduced adherence. There was greater adherence by bacteria from static cultures than by those from shaken cultures and by bacteria cultured in brain–heart infusion (BHI) plus NaHCO3 (BHIN) than by bacteria cultured in BHI. In contrast, in pig ileal loops, bacteria cultured in MB adhered well to enterocytes, and prior exposure to pH 2.5 had no effect on adherence. Among several media tested for their effect on bacterial adherence in the pig intestine, MB and BHIN proved to be the best. Bacterial adherence was dose-dependent and was more extensive in the ileum than in the colon. This study demonstrated that there are remarkable differences between culture conditions that promote adherence of an EHEC O157:H7 strain in vitro and in vivo, that culture conditions profoundly affect adherence to epithelial cells in vitro and in vivo, and that pig ileal loops are better suited to adherence studies than are colon loops. PMID:21731177

Doppler-guided hemorrhoidal artery ligation does not offer any advantage over suture ligation of grade 3 symptomatic hemorrhoids.

PubMed

Gupta, P J; Kalaskar, S; Taori, S; Heda, P S

2011-12-01

Doppler-guided ligation of hemorrhoidal vessels is being proposed as a treatment of grade 2 and 3 hemorrhoids. Many researchers are coupling this procedure with mucopexy or lifting of hemorrhoids to control the prolapse more effectively. The present study was conducted in patients with 3rd-degree hemorrhoids to determine the usefulness of Doppler-guided hemorrhoidal artery ligation compared to mucopexy of prolapsing hemorrhoids and to compare it with mere mucopexy of the hemorrhoids. A double-blind, randomized controlled study was conducted on 48 consecutive patients with grade III hemorrhoids requiring surgery. The patients were randomized into two groups. Half of them were treated with ligation and mucopexy [SL], while the remaining patients underwent a Doppler-guided hemorrhoidal artery ligation followed by ligation and mucopexy [DSL]. The patients were examined by a blinded independent observer at 2, 4, and 6 weeks and at the end of 1 year after the operation to evaluate postoperative pain scores, amount of analgesics consumed, and complications encountered. The observer also assessed recurrence of hemorrhoids after 1 year. Operative time was significantly longer in the DSL group (31 min vs. 9 min P < 0.003). The postoperative pain score was significantly higher in the Doppler group [4.4 vs. 2.2, P < 0.002 (visual analogue scale)]. The mean total analgesic dose and duration of pain control using analgesics were greater and longer for the Doppler group than for the SL group (17 vs. 11 tablets, and 13 days vs. 9 days, respectively; P < 0. 01). Complications were similar in both the groups. At 1-year follow-up, the recurrence of hemorrhoids was not statistically significant in either group (4 patients in SL group and 3 patients in DSL group; P < 0.93). Suture ligation of hemorrhoids is a simple, cost-effective, and convenient modality for treating grade 3 hemorrhoids. Doppler assistance in ligating the hemorrhoidal vessels prior to hemorrhoidal mucopexy offers no advantage and is a time-consuming procedure.

The HubBLe trial: haemorrhoidal artery ligation (HAL) versus rubber band ligation (RBL) for haemorrhoids.

PubMed

Tiernan, Jim; Hind, Daniel; Watson, Angus; Wailoo, Allan J; Bradburn, Michael; Shephard, Neil; Biggs, Katie; Brown, Steven

2012-10-25

Haemorrhoids (piles) are a very common condition seen in surgical clinics. After exclusion of more sinister causes of haemorrhoidal symptoms (rectal bleeding, perianal irritation and prolapse), the best option for treatment depends upon persistence and severity of the symptoms. Minor symptoms often respond to conservative treatment such as dietary fibre and reassurance. For more severe symptoms treatment such as rubber band ligation may be therapeutic and is a very commonly performed procedure in the surgical outpatient setting. Surgery is usually reserved for those who have more severe symptoms, as well as those who do not respond to non-operative therapy; surgical techniques include haemorrhoidectomy and haemorrhoidopexy. More recently, haemorrhoidal artery ligation has been introduced as a minimally invasive, non destructive surgical option.There are substantial data in the literature concerning efficacy and safety of 'rubber band ligation including multiple comparisons with other interventions, though there are no studies comparing it to haemorrhoidal artery ligation. A recent overview has been carried out by the National Institute for Health and Clinical Excellence which concludes that current evidence shows haemorrhoidal artery ligation to be a safe alternative to haemorrhoidectomy and haemorrhoidopexy though it also highlights the lack of good quality data as evidence for the advantages of the technique. The aim of this study is to establish the clinical effectiveness and cost effectiveness of haemorrhoidal artery ligation compared with conventional rubber band ligation in the treatment of people with symptomatic second or third degree (Grade II or Grade III) haemorrhoids. A multi-centre, parallel group randomised controlled trial. The primary outcome is patient-reported symptom recurrence twelve months following the intervention. Secondary outcome measures relate to symptoms, complications, health resource use, health related quality of life and cost effectiveness following the intervention. 350 patients with grade II or grade III haemorrhoids will be recruited in surgical departments in up to 14 NHS hospitals. A multi-centre, parallel group randomised controlled trial. Block randomisation by centre will be used, with 175 participants randomised to each group. The results of the research will help inform future practice for the treatment of grade II and III haemorrhoids. ISRCTN41394716.

Maintenance of a fully functional digestive system during hibernation in the European hamster, a food-storing hibernator.

PubMed

Weitten, Mathieu; Oudart, Hugues; Habold, Caroline

2016-03-01

Some small mammals limit energy expenditure during winter conditions through torpor bouts, which are characterized by a decrease in body temperature and metabolic rate. Individuals arise periodically from torpor to restore critical functions requiring euthermia. Although most of the species involved do not feed during hibernation and rely on body reserves to fulfil energy requirements (fat-storing species), others hoard food in a burrow (food-storing species) and can feed during interbout euthermy. Whereas fat-storing species undergo a marked atrophy of the digestive tract, food-storing species have to maintain a functional digestive system during hibernation. Our study aimed to evaluate the absorption capacities of a food-storing species, the European hamster, throughout the annual cycle. In vivo intestinal perfusions were conducted in different groups of hamsters (n=5) during the different life periods, namely before hibernation, in torpor, during interbout euthermy, and during summer rest. The triglyceride, non-esterified free fatty acid, starch, glucose and protein composition of the perfusate was evaluated before and after the 1h perfusion of a closed intestinal loop. Triglyceride, starch and protein hydrolysis rates were similar in hibernating (torpid and euthermic) and non-hibernating hamsters. Intestinal absorption of free fatty acid was also similar in all groups. However, glucose uptake rate was higher during hibernation than during the summer. In contrast with fat-storing species, the intestinal absorption capacities of food-storing species are fully maintained during hibernation to optimize nutrient assimilation during short interbout euthermy. In particular, glucose uptake rate is increased during hibernation to restore glycaemia and ensure glucose-dependent pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

pH-sensitive thiolated nanoparticles facilitate the oral delivery of insulin in vitro and in vivo

NASA Astrophysics Data System (ADS)

Zhang, Yan; Lin, Xia; Du, Xuli; Geng, Sicong; Li, Hongren; Sun, Hong; Tang, Xing; Xiao, Wei

2015-02-01

In this work, we designed and developed a delivery system composed of enteric Eudragit L100-cysteine/reduced glutathione nanoparticles (Eul-cys/GSH NPs) for oral delivery of insulin. First, interactions between Eul-cys and mucin glycoproteins, which are believed to be the result of disulfide bonds, were confirmed using rheology experiments. Subsequently, the insulin-loaded Eul-cys/GSH NPs were prepared by the diffusion method using the rich gel network multipore structure at the surface of the Eul-cys when the pH was higher than the p Ka of Eul-cys polymer. The Eul-cys/GSH NPs obtained were characterized by dynamic light scattering, transmission electron microscopy, and atomic force microscopy. The results obtained showed that the average particle size ranged from 240 to 280 nm, and the particles were almost spherical in shape. The in vitro drug release results showed that the Eul-cys/GSH NPs retained a large amount of insulin in simulated gastric fluid, while a significant insulin release was found in simulated intestinal fluid. The in situ release study suggested that NPs released a greater amount of FITC-insulin (49.2 %) into the intestinal mucus layer compared with that of FITC-insulin solution (16.4 %), which facilitating insulin delivery through the intestinal mucosa. Eul-cys/GSH NPs exhibited promising mucoadhesive properties demonstrated using an in vitro cell model. Consequently, NPs were introduced into the ileum loop of healthy rats, thus enhancing the intestinal absorption of insulin and providing a prolonged reduction in blood glucose levels. These results suggest that Eul-cys/GSH NPs may be a promising delivery system for the treatment of diabetes.

Ferroportin mediates the intestinal absorption of iron from a nanoparticulate ferritin core mimetic in mice

PubMed Central

Aslam, Mohamad F.; Frazer, David M.; Faria, Nuno; Bruggraber, Sylvaine F. A.; Wilkins, Sarah J.; Mirciov, Cornel; Powell, Jonathan J.; Anderson, Greg J.; Pereira, Dora I. A.

2014-01-01

The ferritin core is composed of fine nanoparticulate Fe3+ oxohydroxide, and we have developed a synthetic mimetic, nanoparticulate Fe3+ polyoxohydroxide (nanoFe3+). The aim of this study was to determine how dietary iron derived in this fashion is absorbed in the duodenum. Following a 4 wk run-in on an Fe-deficient diet, mice with intestinal-specific disruption of the Fpn-1 gene (Fpn-KO), or littermate wild-type (WT) controls, were supplemented with Fe2+ sulfate (FeSO4), nanoFe3+, or no added Fe for a further 4 wk. A control group was Fe sufficient throughout. Direct intestinal absorption of nanoFe3+ was investigated using isolated duodenal loops. Our data show that FeSO4 and nanoFe3+ are equally bioavailable in WT mice, and at wk 8 the mean ± sem hemoglobin increase was 18 ± 7 g/L in the FeSO4 group and 30 ± 5 g/L in the nanoFe3+ group. Oral iron failed to be utilized by Fpn-KO mice and was retained in enterocytes, irrespective of the iron source. In summary, although nanoFe3+ is taken up directly by the duodenum its homeostasis is under the normal regulatory control of dietary iron absorption, namely via ferroportin-dependent efflux from enterocytes, and thus offers potential as a novel oral iron supplement.—Aslam, M. F., Frazer, D. M., Faria, N., Bruggraber, S. F. A., Wilkins, S. J., Mirciov, C., Powell, J. J., Anderson, G. J., Pereira, D. I. A. Ferroportin mediates the intestinal absorption of iron from a nanoparticulate ferritin core mimetic in mice. PMID:24776745

Zampanolide Binding to Tubulin Indicates Cross-Talk of Taxane Site with Colchicine and Nucleotide Sites.

PubMed

Field, Jessica J; Pera, Benet; Gallego, Juan Estévez; Calvo, Enrique; Rodríguez-Salarichs, Javier; Sáez-Calvo, Gonzalo; Zuwerra, Didier; Jordi, Michel; Andreu, José M; Prota, Andrea E; Ménchon, Grégory; Miller, John H; Altmann, Karl-Heinz; Díaz, J Fernando

2018-03-23

The marine natural product zampanolide and analogues thereof constitute a new chemotype of taxoid site microtubule-stabilizing agents with a covalent mechanism of action. Zampanolide-ligated tubulin has the switch-activation loop (M-loop) in the assembly prone form and, thus, represents an assembly activated state of the protein. In this study, we have characterized the biochemical properties of the covalently modified, activated tubulin dimer, and we have determined the effect of zampanolide on tubulin association and the binding of tubulin ligands at other binding sites. Tubulin activation by zampanolide does not affect its longitudinal oligomerization but does alter its lateral association properties. The covalent binding of zampanolide to β-tubulin affects both the colchicine site, causing a change of the quantum yield of the bound ligand, and the exchangeable nucleotide binding site, reducing the affinity for the nucleotide. While these global effects do not change the binding affinity of 2-methoxy-5-(2,3,4-trimethoxyphenyl)-2,4,6-cycloheptatrien-1-one (MTC) (a reversible binder of the colchicine site), the binding affinity of a fluorescent analogue of GTP (Mant-GTP) at the nucleotide E-site is reduced from 12 ± 2 × 10 5 M -1 in the case of unmodified tubulin to 1.4 ± 0.3 × 10 5 M -1 in the case of the zampanolide tubulin adduct, indicating signal transmission between the taxane site and the colchicine and nucleotide sites of β-tubulin.

Superficial dorsal vein injury/thrombosis presenting as false penile fracture requiring dorsal venous ligation.

PubMed

Rafiei, Arash; Hakky, Tariq S; Martinez, Daniel; Parker, Justin; Carrion, Rafael

2014-12-01

Conditions mimicking penile fracture are extremely rare and have been seldom described. To describe a patient with false penile fracture who presented with superficial dorsal vein injury/thrombosis managed with ligation. A 33-year-old male presented with penile swelling and ecchymosis after intercourse. A penile ultrasound demonstrated a thrombosed superficial dorsal vein but also questionable fracture of the tunica albuginea. As the thrombus was expanding, he was emergently taken to the operating room for exploration and required only dorsal venous ligation. Postoperatively, patient's Sexual Health Inventory for Men score was 23, and he had no issues with erections or sexual intercourse. Early exploration of patients with suspected penile fracture provides excellent results with maintenance of erectile function. Also, in the setting of dorsal vein thrombosis, ligation preserves the integrity of the penile tissues and avoids unnecessary complications from conservative management. Rafiei A, Hakky TS, Martinez D, Parker J, and Carrion R. Superficial dorsal vein injury/thrombosis presenting as false penile fracture requiring dorsal venous ligation.

Can interposition of a silicone implant after sapheno-femoral ligation prevent recurrent varicose veins?

PubMed

De Maeseneer, M G; Giuliani, D R; Van Schil, P E; De Hert, S G

2002-11-01

To investigate whether a silicone implant at the sapheno-femoral ligation site could prevent recurrent varicosities. Two non-randomised groups of patients were studied prospectively. In group A 173 patients and 212 limbs had sapheno-femoral ligation, while 172 patients and 210 limbs additionally had a piece (2x3cm) of silicone sheet sutured to the saphenous stump to cover the anterior half of the common femoral vein. The implant was fixed in apposition to the deep vein by carefully closing the cribriform fascia. Colour duplex scanning was performed after 2 and 12 months. In the no implant group neovascularisation was observed in 35 (17%) after 12 months, but only in 13 (6%) limbs treated with a silicone implant (p<0.05). Interposition of a partition of silicone implant seems to lower the incidence of neovascularisation one year after saphenofemoral ligation. This technique may constitute an efficient method to prevent recurrence at the correctly ligated saphenous stump.

Evaluation of the force generated by gradual deflection of orthodontic wires in conventional metallic, esthetic, and self-ligating brackets.

PubMed

Francisconi, Manoela Fávaro; Janson, Guilherme; Henriques, José Fernando Castanha; Freitas, Karina Maria Salvatore de

2016-01-01

The purpose of this study was to evaluate the deflection forces of Nitinol orthodontic wires placed in different types of brackets: metallic, reinforced polycarbonate with metallic slots, sapphire, passive and active self-ligating, by assessing strength values variation according to gradual increase in wire diameter and deflection and comparing different combinations in the different deflections. Specimens were set in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using the ISO 15841 protocol. Data were subjected to One-way ANOVA, followed by Tukey tests (p<0.05). Self-ligating brackets presented the most similar behavior to each other. For conventional brackets there was no consistent behavior for any of the deflections studied. Self-ligating brackets presented the most consistent and predictable results while conventional brackets, as esthetic brackets, showed very different patterns of forces. Self-ligating brackets showed higher strength in all deflections when compared with the others, in 0.020-inch wires.

Coil occlusion of residual shunts after surgical closure of patent ductus arteriosus.

PubMed

Fujii, Yoko; Keene, Bruce W; Mathews, Kyle G; Atkins, Clarke E; Defrancesco, Teresa C; Hardie, Elizabeth M; Wakao, Yoshito

2006-12-01

OBJECTIVE; To describe use of coil embolization to occlude residual flow through a patent ductus arteriosus (PDA) after incomplete surgical ligation. Clinical study. Dogs (n=4) with continuous murmur after surgical ligation of PDA. After PDA ligation, residual ductal flow through the PDA was visible on color-flow Doppler examination and left ventricular end-diastolic diameter remained increased. Coil embolization by an arterial approach was performed to achieve complete occlusion of the PDA. Embolization coils were delivered without complications and hemodynamically successful occlusion was achieved. Doppler-visible flow resolved in 2 dogs within 3 months after embolization. Left ventricular end-diastolic diameter indexed to body weight decreased in all dogs. Transcatheter coil embolization appears to be a safe and minimally invasive procedure for complete occlusion of residual PDA flow after incomplete surgical ligation. Transcatheter coil embolization should be considered for correction of hemodynamically significant residual shunts in dogs that have incomplete PDA occlusion after open surgical ligation.

Efficient peptide ligation between allyl-protected Asp and Cys followed by palladium-mediated deprotection.

PubMed

Kamo, Naoki; Hayashi, Gosuke; Okamoto, Akimitsu

2018-04-24

An efficient method for peptide ligation between C-terminal Asp(OAllyl) and N-terminal Cys has been developed. Peptide ligation and removal of the allyl group at the Asp carboxylate side chain proceeded in one pot by adding a small amount of Pd/TPPTS complex. Based on this efficient synthetic method, PEP-19 (61 amino acids), which is highly expressed in Purkinje cells, was synthesized.

Hubble trial: time to stick to basics for treatment of haemorrhoids?

PubMed

Brown, S R

2017-01-01

The results of the Hubble trial, a randomised controlled trial comparing haemorrhoidal artery ligation with rubber band ligation for early-grade prolapsing haemorrhoids, are discussed. The difficulties in defining treatment success are debated along with the trial design highlighting the pitfalls of previous research. A finding that haemorrhoidal artery ligation is not necessarily superior to cheap alternatives has implications for current practice and future commissioning of surgeons.

Mechanisms Underlying the Breast Cancer Susceptibility Locus Mcs5a

DTIC Science & Technology

2010-07-01

fixed using formaldehyde . The extracted fixed chromatin is digested with a restriction enzyme and religated in a strongly dilute fashion. In this...procedure the ligation of genetic elements that were glued together by formaldehyde fixation is favored over ligation of random elements. Following... digested and randomly ligated control template containing all restriction fragments of interest in equal molarity. To investigate the Mcs5a1-Mcs5a2

Can 5-aminosalicylic acid suppository decrease the pain after rectal band ligation?

PubMed

Kayhan, Burcak; Ozer, Digdem; Akdogan, Meral; Ozaslan, Ersan; Yuksel, Osman

2008-06-14

To investigate the effect of 5-aminosalicylic acid (5-ASA) suppositories on rectal band ligation-induced pain. Sixty patients were randomized into two treatment groups. Our results showed that there was no difference between 5-ASA suppository group and the control group for pain control. 5-ASA may be an alternative treatment for hemorrhoids; however, it does not affect the rectal band ligation-induced pain.

Transcatheter recanalization of ligated main pulmonary artery.

PubMed

Bhole, Vinay; Wright, John G C; Stumper, Oliver

2007-04-01

A 12.5-year-old boy with tricuspid atresia and quadriplegic cerebral palsy presented with increasing cyanosis after previous palliation with a cavopulmonary shunt and ligation of the main pulmonary artery (MPA). Because of severe physical disabilities he was not considered suitable for Fontan completion. He underwent successful transcatheter stent recanalization of the ligated MPA. This re-established anterograde flow to the pulmonary arteries resulting in marked improvement in saturations.

Retroperitoneal Varix ligation with sclerotherapy: a prospective randomized comparative study

PubMed Central

Abdelsalam, Yaser M.; Saeed, Waleed M.; Elganainy, Ehab O.; Ahmed, Abdelfatah I.

2017-01-01

Introduction The aim of this article is to compare the results of high varix ligation with and without sclerotherapy. Material and methods Between November 2014 and December 2015, sixty patients with varicocele were included in this study. Patients were divided into two equal groups; group I (underwent high varix ligation), and group II (underwent high varix ligation with a retrograde injection of 2 mL of 5% ethanolamine oleate in the lower end of the bisected gonadal vein). The operative time, intra- and postoperative complications, postoperative pain, improvement of semen parameters, incidence of recurrence and achieving of unassisted pregnancy were recorded for both groups. Results The age range was 19–34 years in group I and 21–37 years in group II. The operative time was shorter in group I (34.6 ±7.81 min) than group II (43.3 ±8.5 min) (P <0.001), which was statistically significant. Improvement of semen parameters and the occurrence of spontaneous pregnancy were insignificant between both groups. No intraoperative complications occurred. The postoperative complications were statistically insignificant in both groups. Conclusions Combined varix ligation with retrograde sclerotherapy does not offer significant advantages over high varix ligation alone with a longer operative time and prolonged post-operative pain. PMID:29104794

Air-powder polishing on self-ligating brackets after clinical use: effects on debris levels.

PubMed

Aragón, Mônica L S Castro; Lima, Leandro Santiago; Normando, David

2016-01-01

Debris buildup on brackets and arch surfaces is one of the main factors that can influence the intensity of friction between bracket and orthodontic wire. This study sought to evaluate the effect of air-powder polishing cleaning on debris levels of self-ligating ceramic brackets at the end of orthodontic treatment, compared to the behavior of conventional brackets. Debris levels were evaluated in metal conventional orthodontic brackets (n = 42) and ceramic self-ligating brackets (n = 42) on canines and premolars, arranged in pairs. There were brackets with and without air-powder polishing. At the end of orthodontic treatment, a hemiarch served as control and the contralateral hemiarch underwent prophylaxis with air-powder polishing. Debris buildup in bracket slots was assessed through images, and Wilcoxon test was used to analyze the results. The median debris levels were statistically lower in the conventional metal brackets compared to self-ligating ones (p = 0.02), regarding brackets not submitted to air-powder polishing. Polishing significantly reduced debris buildup to zero in both systems, without differences between groups. Ceramic self-ligating brackets have a higher debris buildup in comparison to conventional metal brackets in vivo, but prophylaxis with sodium bicarbonate jet was effective in reducing debris levels in self-ligating and also in conventional brackets.

Solid-phase proximity ligation assays for individual or parallel protein analyses with readout via real-time PCR or sequencing.

PubMed

Nong, Rachel Yuan; Wu, Di; Yan, Junhong; Hammond, Maria; Gu, Gucci Jijuan; Kamali-Moghaddam, Masood; Landegren, Ulf; Darmanis, Spyros

2013-06-01

Solid-phase proximity ligation assays share properties with the classical sandwich immunoassays for protein detection. The proteins captured via antibodies on solid supports are, however, detected not by single antibodies with detectable functions, but by pairs of antibodies with attached DNA strands. Upon recognition by these sets of three antibodies, pairs of DNA strands brought in proximity are joined by ligation. The ligated reporter DNA strands are then detected via methods such as real-time PCR or next-generation sequencing (NGS). We describe how to construct assays that can offer improved detection specificity by virtue of recognition by three antibodies, as well as enhanced sensitivity owing to reduced background and amplified detection. Finally, we also illustrate how the assays can be applied for parallel detection of proteins, taking advantage of the oligonucleotide ligation step to avoid background problems that might arise with multiplexing. The protocol for the singleplex solid-phase proximity ligation assay takes ~5 h. The multiplex version of the assay takes 7-8 h depending on whether quantitative PCR (qPCR) or sequencing is used as the readout. The time for the sequencing-based protocol includes the library preparation but not the actual sequencing, as times may vary based on the choice of sequencing platform.

Antisecretory activity from the flowers of Chiranthodendron pentadactylon and its flavonoids on intestinal fluid accumulation induced by Vibrio cholerae toxin in rats.

PubMed

Velázquez, Claudia; Calzada, Fernando; Esquivel, Baldomero; Barbosa, Elizabeth; Calzada, Samuel

2009-12-10

The flowers of Chiranthodendron pentadactylon Larreat. (Sterculiaceae) has been traditionally used as folk medicine in Mexico for the treatment of gastrointestinal disorders such as diarrhea and dysentery. This study aimed to assess the antisecretory activity which supports the therapeutic use of Chiranthodendron pentadactylon and its flavonoids to treat diarrhea. The methanol extract of Chiranthodendron pentadactylon, subsequent fractions, and flavonoids were evaluated on cholera toxin-induced intestinal secretion in rat jejunal loops model. Three antisecretory flavonoids were isolated by bioassay-guided purification, namely, isoquercitrin 3, (+)-catechin 4 and (-)-epicatechin 5. Among them, epicatechin exhibited the most potent antisecretory activity with ID(50) of 8.3 microM/kg. Its potency was close that of to loperamide (ID(50) 6.1 microM/kg), drug used as control. Isoquercitrin (ID(50) 19.2 microM/kg) and catechin (ID(50) 51.7 microM/kg) showed moderate and weak activity, respectively. The results of the present study lend some support to the anecdotal report for the traditional use of the flowers of Chiranthodendron pentadactylon in the control of dysentery.

Effect of bacterial sepsis on gluconeogenic capacity in the rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holman, J.M. Jr.; Saba, T.M.

Since sepsis places increased demands on the host for energy and on other substrates for tissue repair and host defense, hepatic gluconeogenesis is critical for the host's adaptation to sepsis. Substrate-stimulated gluconeogenesis (i.e., gluconeogenic capacity) was assessed by the alanine load method in mannoheptulose-pretreated rats made septic by cecal ligation after laparotomy, as well as by cecal ligation and puncture after laparotomy. Fasted rats subjected to laparotomy only (sham-ligated) and fasted, nonoperated rats (controls) were investigated simultaneously. Following an overnight (-18 to 0 hr) fast, nonoperated animals converted 17.9 +/- 1.5% of (/sup 14/C)alanine to (/sup 14/C)glucose. Continued fasting inmore » nonoperated animals resulted in enhanced (P less than 0.05) gluconeogenic capacity (6 hr = 27.2 +/- 3.0%; 24 hr = 26.2 +/- 1.9%; and 48 hr = 28.5 +/- 2.6%) relative to Time 0. Laparotomy alone (sham ligation) delayed the fasting-induced increase (P less than 0.05) in gluconeogenesis capacity (6 hr = 21.1 +/- 1.2%; 24 hr = 18.5 +/- 1.3%; 48 hr = 27.8 +/- 1.0%) relative to Time 0. In contrast, postoperative sepsis produced a sustained depression (P less than 0.05) of gluconeogenic capacity relative to nonoperated sham-ligated controls at 48 hr (cecal ligation, 18.4 +/- 1.4%; and cecal ligation and puncture, 18.8 +/- 1.2%). Thus, (1) fasting enhances hepatic gluconeogenic capacity; (2) surgical trauma transiently blunts the gluconeogenic response to fasting; and (3) sepsis undermines the gluconeogenic response to fasting.« less

Butelase-mediated cyclization and ligation of peptides and proteins.

PubMed

Nguyen, Giang K T; Qiu, Yibo; Cao, Yuan; Hemu, Xinya; Liu, Chuan-Fa; Tam, James P

2016-10-01

Enzymes that catalyze efficient macrocyclization or site-specific ligation of peptides and proteins can enable tools for drug design and protein engineering. Here we describe a protocol to use butelase 1, a recently discovered peptide ligase, for high-efficiency cyclization and ligation of peptides and proteins ranging in size from 10 to >200 residues. Butelase 1 is the fastest known ligase and is found in pods of the common medicinal plant Clitoria ternatea (also known as butterfly pea). It has a very simple C-terminal-specific recognition motif that requires Asn/Asp (Asx) at the P1 position and a dipeptide His-Val at the P1' and P2' positions. Substrates for butelase-mediated ligation can be prepared by standard Fmoc (9-fluorenylmethyloxycarbonyl) chemistry or recombinant expression with the minimal addition of this tripeptide Asn-His-Val motif at the C terminus. Butelase 1 achieves cyclizations that are 20,000 times faster than those of sortase A, a commonly used enzyme for backbone cyclization. Unlike sortase A, butelase is traceless, and it can be used for the total synthesis of naturally occurring peptides and proteins. Furthermore, butelase 1 is also useful for intermolecular ligations and synthesis of peptide or protein thioesters, which are versatile activated intermediates necessary for and compatible with many chemical ligation methods. The protocol describes steps for isolation and purification of butelase 1 from plant extract using a four-step chromatography procedure, which takes ∼3 d. We then describe steps for intramolecular cyclization, intermolecular ligation and butelase-mediated synthesis of protein thioesters. Butelase reactions are generally completed within minutes and often achieve excellent yields.

Relationships between alterations in glutathione metabolism and the disposition of inorganic mercury in rats: effects of biliary ligation and chemically induced modulation of glutathione status.

PubMed

Zalups, R K; Barfuss, D W; Lash, L H

1999-12-15

Influences of biliary ligation and systemic depletion of glutathione (GSH) or modulation of GSH status on the disposition of a low, non-nephrotoxic i.v. dose of inorganic mercury were evaluated in rats in the present study. Renal and hepatic disposition, and the urinary and fecal excretion, of inorganic mercury were assessed 24 h after the injection of a 0.5-micromol/kg dose of mercuric chloride in control rats and rats pretreated with acivicin (two 10-mg/kg i.p. doses in 2 ml/kg normal saline, 90 min apart, 60 min before mercuric chloride), buthionine sulfoximine (BSO; 2 mmol/kg i.v. in 4 ml/kg normal saline, 2 h before mercuric chloride) or diethylmaleate (DEM; 3.37 mmol/kg i.p. in 2 ml/kg corn oil, 2 h before mercuric chloride) that either underwent or did not undergo acute biliary ligation prior to the injection of mercury. Among the groups that did not undergo biliary ligation, the pretreatments used to alter GSH status systemically had varying effects on the disposition of inorganic mercury in the kidneys, liver, and blood. Biliary ligation caused the net renal accumulation of mercury to decrease under all pretreatment conditions. By contrast, biliary ligation caused significant increases in the hepatic burden of mercury in all pretreatment groups except in theacivicin-pretreated group. Blood levels of mercury also increased as a result of biliary ligation, regardless of the type of pretreatment used. The present findings indicate that biliary ligation combined with methods used to modulate GSH status systemically have additive effects with respect to causing reductions in the net renal accumulation of mercury. Additionally, the findings indicate that at least some fraction of the renal accumulation of inorganic mercury is linked mechanistically to the hepato-biliary system.

Ligation versus no ligation of spontaneous portosystemic shunts during liver transplantation: Audit of a prospective series of 66 consecutive patients.

PubMed

Gomez Gavara, Concepcion; Bhangui, Prashant; Salloum, Chady; Osseis, Michael; Esposito, Francesco; Moussallem, Toufic; Lahat, Eylon; Fuentes, Liliana; Compagnon, Philippe; Ngongang, Norbert; Lim, Chetana; Azoulay, Daniel

2018-04-01

The management of large spontaneous portosystemic shunt (SPSS) during liver transplantation (LT) is a matter of debate. The aim of this study is to compare the short-term and longterm outcomes of SPSS ligation versus nonligation during LT, when both options are available. From 2011 to 2017, 66 patients with SPSS underwent LT: 56 without and 10 with portal vein thrombosis (PVT), all of whom underwent successful thrombectomy and could have portoportal reconstruction. The SPSS were either splenorenal (n = 40; 60.6%), left gastric (n = 16; 24.2%), or mesenterico-iliac (n = 10; 15.1%). Following portoportal anastomosis, the SPSS was ligated in 36 (54.4%) patients and left in place in 30 (45.5%) patients, based on the effect of the SPSS clamping/unclamping test on portal vein flow during the anhepatic phase. Intraoperatively, satisfactory portal flow was obtained in both groups. Primary nonfunction (PNF) and primary dysfunction (PDF) rates did not differ significantly between the 2 groups. Nonligation of SPSS was significantly associated with a higher rate of postoperative encephalopathy (P < 0.001) and major postoperative morbidity (P = 0.02). PVT occurred in 0 and 3 patients in the ligated and nonligated shunt group, respectively (P = 0.08). A composite end point, which included the relevant complications in the setting of SPSS in LT (ie, PNF and PDF, PVT, and encephalopathy) was present in 16 (44.4%) and 22 (73.3%) patients of the ligated and nonligated shunt group, respectively (P = 0.02). Patient (P = 0.05) and graft (P = 0.02) survival rates were better in the ligated shunt group. In conclusion, the present study supports routine ligation of large SPSS during LT whenever feasible. Liver Transplantation 24 505-515 2018 AASLD. © 2018 by the American Association for the Study of Liver Diseases.

Rhubarb Monomers Protect Intestinal Mucosal Barrier in Sepsis via Junction Proteins

PubMed Central

Wang, Lyu; Cui, Yun-Liang; Zhang, Zhe; Lin, Zhao-Fen; Chen, De-Chang

2017-01-01

Background: Leakage of the intestinal mucosal barrier may cause translocation of bacteria, then leading to multiorgan failure. This study hypothesized that rhubarb monomers might protect the gut mucosal barrier in sepsis through junction proteins. Methods: Healthy male Sprague-Dawley rats (weighing 230–250 g) under anesthesia and sedation were subjected to cecal ligation and perforation (CLP). After surgical preparation, rats were randomly assigned to eight groups (n = 6 or 8 each group): sham group (Group A: normal saline gavage); sepsis group (Group B: normal saline gavage); Group C (intraperitoneally, dexamethasone 0.5 mg/kg) immediately after CLP surgery; and rhubarb monomer (100 mg/kg in normal saline)-treated groups (Group D: rhein; Group E: emodin; Group F: 3,8-dihydroxy-1-methyl-anthraquinone-2-carboxylic acid; Group G: 1-O-caffeoyl-2-(4-hydroxy-O-cinnamoyl)-D-glucose; and Group H: daucosterol linoleate). Animals were sacrificed after 24 h. Intestinal histology, lactulose, mannitol concentrations were measured, and zonula occludens (ZO)-1, occludin and claudin-5 transcription (polymerase chain reaction), translation (by Western blot analysis), and expression (by immunohistochemistry) were also measured. Results: Intestinal histology revealed injury to intestinal mucosal villi induced by sepsis in Group B, compared with Group A. Compared with Group A (0.17 ± 0.41), the pathological scores in Groups B (2.83 ± 0.41, P < 0.001), C (1.83 ± 0.41, P < 0.001), D (2.00 ± 0.63, P < 0.001), E (1.83 ± 0.41, P < 0.001), F (1.83 ± 0.75, P < 0.001), G (2.17 ± 0.41, P < 0.001), and H (1.83 ± 0.41, P < 0.001) were significantly increased. Lactulose/mannitol (L/M) ratio in Group B (0.046 ± 0.003) was significantly higher than in Group A (0.013 ± 0.001, P < 0.001) while L/M ratios in Groups C (0.028 ± 0.002, P < 0.001), D (0.029 ± 0.003, P < 0.001), E (0.026 ± 0.003, P < 0.001), F (0.027 ± 0.003, P < 0.001), G (0.030 ± 0.005, P < 0.001), and H (0.026 ± 0.002, P < 0.001) were significantly lower than that in Group B. ZO-1, occludin and claudin-5 transcription, translation, and expression in Group B were significantly lower than that in Group A (P < 0.001), but they were significantly higher in Groups C, D, E, F, G, and H than those in Group B (P < 0.05). Conclusion: Rhubarb monomer treatment ameliorated mucosal damage in sepsis via enhanced transcription, translation, and expression of junction proteins. PMID:28485323

Impact of split completeness on future liver remnant hypertrophy in associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) in hepatocellular carcinoma: Complete-ALPPS versus partial-ALPPS.

PubMed

Chan, Albert C Y; Chok, Kenneth; Dai, Jeff W C; Lo, Chung Mau

2017-02-01

Recent evidence suggested that associating liver partition and portal vein ligation for staged hepatectomy with a partial split could effectively induce the same degree of future liver remnant hypertrophy as a complete split in non-cirrhotic and non-cholestatic livers with better postoperative safety profiles. Our aim was to evaluate if the same phenomenon could be applied to hepatitis-related chronic liver diseases. In the study, 25 patients who underwent associating liver partition and portal vein ligation for staged hepatectomy from October 2013 to January 2016 for hepatocellular carcinoma were analyzed. Partial-associating liver partition and portal vein ligation for staged hepatectomy (n = 12) was defined as 50-80% of the transection surface split and complete-associating liver partition and portal vein ligation for staged hepatectomy (n = 13) was split down to inferior vena cava. Perioperative outcomes stratified by split completeness were evaluated. There was no significant difference in operating times and blood loss for stage I and II operations between complete-associating liver partition and portal vein ligation for staged hepatectomy and partial-associating liver partition and portal vein ligation for staged hepatectomy. All patients underwent stage II operation without any inter-stage complications. Complete split induced greater future liver remnant hypertrophy than partial split (hypertrophy rate: 31.2 vs 17.5 mL/day, P = .022) with more pronounced effect in chronic hepatitis (P = .007) than cirrhosis (P = .283). Complete-associating liver partition and portal vein ligation for staged hepatectomy was more likely to attain a future liver remnant/estimated standard liver volume ratio >35% within 10 days (76.9% vs 33.3%, P = .024) and proceed to stage II within 14 days after stage I (100% vs 58.4%, P = .009). The overall postoperative morbidity (≥grade 3a) after stage II was 16% (complete versus partial split: 7.7% vs 25%, P = .238) and hospital mortality after stage II was 8% (complete versus partial split: 0% vs 16.7%, P = .125). Complete-associating liver partition and portal vein ligation for staged hepatectomy induced more rapid future liver remnant hypertrophy than partial-associating liver partition and portal vein ligation for staged hepatectomy without increased perioperative risk in chronic liver diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

Unlimited in vitro expansion of adult bi-potent pancreas progenitors through the Lgr5/R-spondin axis

PubMed Central

Huch, Meritxell; Bonfanti, Paola; Boj, Sylvia F; Sato, Toshiro; Loomans, Cindy J M; van de Wetering, Marc; Sojoodi, Mozhdeh; Li, Vivian S W; Schuijers, Jurian; Gracanin, Ana; Ringnalda, Femke; Begthel, Harry; Hamer, Karien; Mulder, Joyce; van Es, Johan H; de Koning, Eelco; Vries, Robert G J; Heimberg, Harry; Clevers, Hans

2013-01-01

Lgr5 marks adult stem cells in multiple adult organs and is a receptor for the Wnt-agonistic R-spondins (RSPOs). Intestinal, stomach and liver Lgr5+ stem cells grow in 3D cultures to form ever-expanding organoids, which resemble the tissues of origin. Wnt signalling is inactive and Lgr5 is not expressed under physiological conditions in the adult pancreas. However, we now report that the Wnt pathway is robustly activated upon injury by partial duct ligation (PDL), concomitant with the appearance of Lgr5 expression in regenerating pancreatic ducts. In vitro, duct fragments from mouse pancreas initiate Lgr5 expression in RSPO1-based cultures, and develop into budding cyst-like structures (organoids) that expand five-fold weekly for >40 weeks. Single isolated duct cells can also be cultured into pancreatic organoids, containing Lgr5 stem/progenitor cells that can be clonally expanded. Clonal pancreas organoids can be induced to differentiate into duct as well as endocrine cells upon transplantation, thus proving their bi-potentiality. PMID:24045232

Copper-free click chemistry in living animals

PubMed Central

Chang, Pamela V.; Prescher, Jennifer A.; Sletten, Ellen M.; Baskin, Jeremy M.; Miller, Isaac A.; Agard, Nicholas J.; Lo, Anderson; Bertozzi, Carolyn R.

2010-01-01

Chemical reactions that enable selective biomolecule labeling in living organisms offer a means to probe biological processes in vivo. Very few reactions possess the requisite bioorthogonality, and, among these, only the Staudinger ligation between azides and triarylphosphines has been employed for direct covalent modification of biomolecules with probes in the mouse, an important model organism for studies of human disease. Here we explore an alternative bioorthogonal reaction, the 1,3-dipolar cycloaddition of azides and cyclooctynes, also known as “Cu-free click chemistry,” for labeling biomolecules in live mice. Mice were administered peracetylated N-azidoacetylmannosamine (Ac4ManNAz) to metabolically label cell-surface sialic acids with azides. After subsequent injection with cyclooctyne reagents, glycoconjugate labeling was observed on isolated splenocytes and in a variety of tissues including the intestines, heart, and liver, with no apparent toxicity. The cyclooctynes tested displayed various labeling efficiencies that likely reflect the combined influence of intrinsic reactivity and bioavailability. These studies establish Cu-free click chemistry as a bioorthogonal reaction that can be executed in the physiologically relevant context of a mouse. PMID:20080615

Inflammation: a way to understanding the evolution of portal hypertension

PubMed Central

Aller, María-Angeles; Arias, Jorge-Luis; Cruz, Arturo; Arias, Jaime

2007-01-01

Background Portal hypertension is a clinical syndrome that manifests as ascites, portosystemic encephalopathy and variceal hemorrhage, and these alterations often lead to death. Hypothesis Splanchnic and/or systemic responses to portal hypertension could have pathophysiological mechanisms similar to those involved in the post-traumatic inflammatory response. The splanchnic and systemic impairments produced throughout the evolution of experimental prehepatic portal hypertension could be considered to have an inflammatory origin. In portal vein ligated rats, portal hypertensive enteropathy, hepatic steatosis and portal hypertensive encephalopathy show phenotypes during their development that can be considered inflammatory, such as: ischemia-reperfusion (vasodilatory response), infiltration by inflammatory cells (mast cells) and bacteria (intestinal translocation of endotoxins and bacteria) and lastly, angiogenesis. Similar inflammatory phenotypes, worsened by chronic liver disease (with anti-oxidant and anti-enzymatic ability reduction) characterize the evolution of portal hypertension and its complications (hepatorenal syndrome, ascites and esophageal variceal hemorrhage) in humans. Conclusion Low-grade inflammation, related to prehepatic portal hypertension, switches to high-grade inflammation with the development of severe and life-threatening complications when associated with chronic liver disease. PMID:17999758

[Magnetic closure for ileostomy (author's transl)].

PubMed

Loygue, J; Salmon, R; Bloch, P

1980-09-20

The Maclet magnetic stoma seal already used by the authors for colostomies was applied to the closure of permanent terminal ileostomies. A reservoir is constructed upstreams of the closure with the last loop of ileum, so that the faeces accumulate and can be evacuated by intermittence. Patients empty the reservoir by removing the cap which blocks the intestinal lumen and introducing a probe into it. The technique was used on 2 patients who had undergone total proctocolectomy for familial polyposis of the colon. One patient has now been followed up for 3 years and the other for 6 months. The perfect continence obtained by this method favourably compares with Kock's continent ileostomy.

Selective binding and transcytosis of Ulex europaeus 1 lectin by mouse Peyer's patch M-cells in vivo.

PubMed

Clark, M A; Jepson, M A; Simmons, N L; Hirst, B H

1995-12-01

The in vivo interaction of the lectin Ulex europaeus agglutinin 1 with mouse Peyer's patch follicle-associated epithelial cells was studied in the mouse Peyer's patch gut loop model by immunofluorescence and electron microscopy. The lectin targets to mouse Peyer's patch M-cells and is rapidly endocytosed and transcytosed. These processes are accompanied by morphological changes in the M-cell microvilli and by redistribution of polymerised actin. The demonstration of selective binding and uptake of a lectin by intestinal M-cells in vivo suggests that M-cell-specific surface glycoconjugates might act as receptors for the selective adhesion/uptake of microorganisms.

The effect of vagotomy and drainage on the small bowel flora

PubMed Central

Browning, G. G.; Buchan, K. A.; Mackay, C.

1974-01-01

The incidence of small intestinal colonization in unoperated duodenal ulcer patients was low and similar to that in the normal population. The majority of patients seven to 10 days following truncal vagotomy and drainage were colonized whereas none of a control group of patients following simple closure of a perforated duodenal ulcer was colonized. In patients with pyloroplasty, this high incidence fell to control levels on average 18 months postoperatively, but in patients with a gastro-jejunostomy, the incidence remained raised probably due to the presence of the afferent loop. Only two patients developed episodic diarrhoea and there was no obvious association with small bowel colonization. PMID:4820640

Enzyme-linked immunosorbent assay for Escherichia coli heat-stable enterotoxin type II.

PubMed Central

Handl, C; Rönnberg, B; Nilsson, B; Olsson, E; Jonsson, H; Flock, J I

1988-01-01

The gene for Escherichia coli heat-stable enterotoxin type II (STII) was fused to the genes for protein A from Staphylococcus aureus and beta-galactosidase in two different expression systems. Antibodies raised in rabbits against the protein A-STII fusion protein recognized the beta-galactosidase-STII fusion protein. The latter fusion protein was used as the immobilized antigen in an enzyme-linked immunosorbent assay (ELISA) for detection of STII. The correlation between the results of the ELISA and the intestinal loop test in piglets was 95%, suggesting that the ELISA can be used to reliably detect STII. Images PMID:3049659

Hemoptysis due to pulmonary pseudosequestration secondary to gastro-pulmonary fistula after a revisional bariatric operation.

PubMed

Santacruz, Carlos Cerdán; Rodríguez, María Conde; Sánchez-Pernaute, Andrés; García, Antonio José Torres

2014-10-01

We report the case of a patient with a history of a complicated revisional bariatric operation who developed a lung pseudosequestration secondary to a gastro-pulmonary fistula. As the patient presented with recurrent hemoptysis, she was initially submitted to embolization of the aberrant vessels and later to a definite operation, which consisted on a diversion of the gastric fistula into a Roux-en-Y intestinal loop. It is an exceptional case about late complications of bariatric surgery, and it underlines the importance of discarding these complications even when the clinical manifestations affect another anatomic region different from the operated abdomen.

Hemoptysis due to pulmonary pseudosequestration secondary to gastro-pulmonary fistula after a revisional bariatric operation

PubMed Central

Santacruz, Carlos Cerdán; Rodríguez, María Conde; Sánchez-Pernaute, Andrés; García, Antonio José Torres

2014-01-01

We report the case of a patient with a history of a complicated revisional bariatric operation who developed a lung pseudosequestration secondary to a gastro-pulmonary fistula. As the patient presented with recurrent hemoptysis, she was initially submitted to embolization of the aberrant vessels and later to a definite operation, which consisted on a diversion of the gastric fistula into a Roux-en-Y intestinal loop. It is an exceptional case about late complications of bariatric surgery, and it underlines the importance of discarding these complications even when the clinical manifestations affect another anatomic region different from the operated abdomen. PMID:25276245

Management of ingested magnets in children.

PubMed

Hussain, Sunny Z; Bousvaros, Athos; Gilger, Mark; Mamula, Petar; Gupta, Sandeep; Kramer, Robert; Noel, R Adam

2012-09-01

We describe a comprehensive algorithm for the management of ingested rare-earth magnets in children. These newer and smaller neodymium magnets sold as adult toys are much stronger than the traditional magnets, and can attract each other with formidable forces. If >1 magnet is swallowed at the same time, or a magnet is co-ingested with another metallic object, the loops of intestine can be squeezed between them resulting in bowel damage including perforations. An algorithm that uses the number of magnets ingested, location of magnets, and the timing of ingestion before intervention helps to delineate the roles of the pediatric gastroenterologists and surgeons in the management of these cases.

[Fetal meconium pseudocyst secondary to in utero perforation of colon transversum and meconium peritonitis].

PubMed

Markov, D; Jekova, N; Ivanov, St; Diavolov, V; Brankov, O

2011-01-01

Fetal bowel intrauterine perforation causes sterile inflammation of the peritoneum, known as meconium peritonitis. In some cases the perforation closes spontaneously, thus forming a meconium pseudocyst between the intestinal loops and the omentum. Meconium peritonitis, complicated by pseudocyst formation, should always be considered when a fetal abdominal mass with diverse echogenicity and hyperechogenic calcifications is observed on prenatal ultrasound. Usually, this is associated with ascites and/or polyhydramnios. The differential diagnosis necessitates exclusion of all other fetal abdominal tumors. We present a case report of meconium pseudocyst diagnosed prenatally at 32 weeks of gestation which was successfully treated by surgery after birth.

Covalent Chemical Ligation Strategy for Mono- and Polyclonal Immunoglobulins at Their Nucleotide Binding Sites.

PubMed

Lac, Diana; Feng, Chun; Bhardwaj, Gaurav; Le, Huong; Tran, Jimmy; Xing, Li; Fung, Gabriel; Liu, Ruiwu; Cheng, Holland; Lam, Kit S

2016-01-20

Nonspecific ligation methods have been traditionally used to chemically modify immunoglobulins. Site-specific ligation of compounds (toxins or ligands) to antibodies has become increasingly important in the fields of therapeutic antibody-drug conjugates and bispecific antibodies. In this present study, we took advantage of the reported nucleotide-binding pocket (NBP) in the Fab arms of immunoglobulins by developing indole-based, 5-fluoro-2,4-dinitrobenzene-derivatized OBOC peptide libraries for the identification of affinity elements that can be used as site-specific derivatization agents against both mono- and polyclonal antibodies. Ligation can occur at any one of the few lysine residues located at the NBP. Immunoconjugates resulting from such affinity elements can be used as therapeutics against cancer or infectious agents.

21 CFR 876.4400 - Hemorrhoidal ligator.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4400 Hemorrhoidal ligator. (a... of a ligature or band placed around the hemorrhoid. (b) Classification. Class II (performance...

Systems Analysis of Early Host Gene Expression Provides Clues for Transient Mycobacterium avium ssp avium vs. Persistent Mycobacterium avium ssp paratuberculosis Intestinal Infections

PubMed Central

Khare, Sangeeta; Drake, Kenneth L.; Lawhon, Sara D.; Nunes, Jairo E. S.; Figueiredo, Josely F.; Rossetti, Carlos A.; Gull, Tamara; Everts, Robin E.; Lewin, Harris. A.; Adams, Leslie Garry

2016-01-01

It has long been a quest in ruminants to understand how two very similar mycobacterial species, Mycobacterium avium ssp. paratuberculosis (MAP) and Mycobacterium avium ssp. avium (MAA) lead to either a chronic persistent infection or a rapid-transient infection, respectively. Here, we hypothesized that when the host immune response is activated by MAP or MAA, the outcome of the infection depends on the early activation of signaling molecules and host temporal gene expression. To test our hypothesis, ligated jejuno-ileal loops including Peyer’s patches in neonatal calves were inoculated with PBS, MAP, or MAA. A temporal analysis of the host transcriptome profile was conducted at several times post-infection (0.5, 1, 2, 4, 8 and 12 hours). When comparing the transcriptional responses of calves infected with the MAA versus MAP, discordant patterns of mucosal expression were clearly evident, and the numbers of unique transcripts altered were moderately less for MAA-infected tissue than were mucosal tissues infected with the MAP. To interpret these complex data, changes in the gene expression were further analyzed by dynamic Bayesian analysis. Bayesian network modeling identified mechanistic genes, gene-to-gene relationships, pathways and Gene Ontologies (GO) biological processes that are involved in specific cell activation during infection. MAP and MAA had significant different pathway perturbation at 0.5 and 12 hours post inoculation. Inverse processes were observed between MAP and MAA response for epithelial cell proliferation, negative regulation of chemotaxis, cell-cell adhesion mediated by integrin and regulation of cytokine-mediated signaling. MAP inoculated tissue had significantly lower expression of phagocytosis receptors such as mannose receptor and complement receptors. This study reveals that perturbation of genes and cellular pathways during MAP infection resulted in host evasion by mucosal membrane barrier weakening to access entry in the ileum, inhibition of Ca signaling associated with decreased phagosome-lysosome fusion as well as phagocytosis inhibition, bias toward Th2 cell immune response accompanied by cell recruitment, cell proliferation and cell differentiation; leading to persistent infection. Contrarily, MAA infection was related to cellular responses associated with activation of molecular pathways that release chemicals and cytokines involved with containment of infection and a strong bias toward Th1 immune response, resulting in a transient infection. PMID:27653506

Systems Analysis of Early Host Gene Expression Provides Clues for Transient Mycobacterium avium ssp avium vs. Persistent Mycobacterium avium ssp paratuberculosis Intestinal Infections.

PubMed

Khare, Sangeeta; Drake, Kenneth L; Lawhon, Sara D; Nunes, Jairo E S; Figueiredo, Josely F; Rossetti, Carlos A; Gull, Tamara; Everts, Robin E; Lewin, Harris A; Adams, Leslie Garry

It has long been a quest in ruminants to understand how two very similar mycobacterial species, Mycobacterium avium ssp. paratuberculosis (MAP) and Mycobacterium avium ssp. avium (MAA) lead to either a chronic persistent infection or a rapid-transient infection, respectively. Here, we hypothesized that when the host immune response is activated by MAP or MAA, the outcome of the infection depends on the early activation of signaling molecules and host temporal gene expression. To test our hypothesis, ligated jejuno-ileal loops including Peyer's patches in neonatal calves were inoculated with PBS, MAP, or MAA. A temporal analysis of the host transcriptome profile was conducted at several times post-infection (0.5, 1, 2, 4, 8 and 12 hours). When comparing the transcriptional responses of calves infected with the MAA versus MAP, discordant patterns of mucosal expression were clearly evident, and the numbers of unique transcripts altered were moderately less for MAA-infected tissue than were mucosal tissues infected with the MAP. To interpret these complex data, changes in the gene expression were further analyzed by dynamic Bayesian analysis. Bayesian network modeling identified mechanistic genes, gene-to-gene relationships, pathways and Gene Ontologies (GO) biological processes that are involved in specific cell activation during infection. MAP and MAA had significant different pathway perturbation at 0.5 and 12 hours post inoculation. Inverse processes were observed between MAP and MAA response for epithelial cell proliferation, negative regulation of chemotaxis, cell-cell adhesion mediated by integrin and regulation of cytokine-mediated signaling. MAP inoculated tissue had significantly lower expression of phagocytosis receptors such as mannose receptor and complement receptors. This study reveals that perturbation of genes and cellular pathways during MAP infection resulted in host evasion by mucosal membrane barrier weakening to access entry in the ileum, inhibition of Ca signaling associated with decreased phagosome-lysosome fusion as well as phagocytosis inhibition, bias toward Th2 cell immune response accompanied by cell recruitment, cell proliferation and cell differentiation; leading to persistent infection. Contrarily, MAA infection was related to cellular responses associated with activation of molecular pathways that release chemicals and cytokines involved with containment of infection and a strong bias toward Th1 immune response, resulting in a transient infection.

Precise Quantitation of MicroRNA in a Single Cell with Droplet Digital PCR Based on Ligation Reaction.

PubMed

Tian, Hui; Sun, Yuanyuan; Liu, Chenghui; Duan, Xinrui; Tang, Wei; Li, Zhengping

2016-12-06

MicroRNA (miRNA) analysis in a single cell is extremely important because it allows deep understanding of the exact correlation between the miRNAs and cell functions. Herein, we wish to report a highly sensitive and precisely quantitative assay for miRNA detection based on ligation-based droplet digital polymerase chain reaction (ddPCR), which permits the quantitation of miRNA in a single cell. In this ligation-based ddPCR assay, two target-specific oligonucleotide probes can be simply designed to be complementary to the half-sequence of the target miRNA, respectively, which avoids the sophisticated design of reverse transcription and provides high specificity to discriminate a single-base difference among miRNAs with simple operations. After the miRNA-templated ligation, the ddPCR partitions individual ligated products into a water-in-oil droplet and digitally counts the fluorescence-positive and negative droplets after PCR amplification for quantification of the target molecules, which possesses the power of precise quantitation and robustness to variation in PCR efficiency. By integrating the advantages of the precise quantification of ddPCR and the simplicity of the ligation-based PCR, the proposed method can sensitively measure let-7a miRNA with a detection limit of 20 aM (12 copies per microliter), and even a single-base difference can be discriminated in let-7 family members. More importantly, due to its high selectivity and sensitivity, the proposed method can achieve precise quantitation of miRNAs in single-cell lysate. Therefore, the ligation-based ddPCR assay may serve as a useful tool to exactly reveal the miRNAs' actions in a single cell, which is of great importance for the study of miRNAs' biofunction as well as for the related biomedical studies.

Isolation of novel ribozymes that ligate AMP-activated RNA substrates

NASA Technical Reports Server (NTRS)

Hager, A. J.; Szostak, J. W.

1997-01-01

BACKGROUND: The protein enzymes RNA ligase and DNA ligase catalyze the ligation of nucleic acids via an adenosine-5'-5'-pyrophosphate 'capped' RNA or DNA intermediate. The activation of nucleic acid substrates by adenosine 5'-monophosphate (AMP) may be a vestige of 'RNA world' catalysis. AMP-activated ligation seems ideally suited for catalysis by ribozymes (RNA enzymes), because an RNA motif capable of tightly and specifically binding AMP has previously been isolated. RESULTS: We used in vitro selection and directed evolution to explore the ability of ribozymes to catalyze the template-directed ligation of AMP-activated RNAs. We subjected a pool of 10(15) RNA molecules, each consisting of long random sequences flanking a mutagenized adenosine triphosphate (ATP) aptamer, to ten rounds of in vitro selection, including three rounds involving mutagenic polymerase chain reaction. Selection was for the ligation of an oligonucleotide to the 5'-capped active pool RNA species. Many different ligase ribozymes were isolated; these ribozymes had rates of reaction up to 0.4 ligations per hour, corresponding to rate accelerations of approximately 5 x10(5) over the templated, but otherwise uncatalyzed, background reaction rate. Three characterized ribozymes catalyzed the formation of 3'-5'-phosphodiester bonds and were highly specific for activation by AMP at the ligation site. CONCLUSIONS: The existence of a new class of ligase ribozymes is consistent with the hypothesis that the unusual mechanism of the biological ligases resulted from a conservation of mechanism during an evolutionary replacement of a primordial ribozyme ligase by a more modern protein enzyme. The newly isolated ligase ribozymes may also provide a starting point for the isolation of ribozymes that catalyze the polymerization of AMP-activated oligonucleotides or mononucleotides, which might have been the prebiotic analogs of nucleoside triphosphates.

Hypotension following patent ductus arteriosus ligation: the role of adrenal hormones.

PubMed

Clyman, Ronald I; Wickremasinghe, Andrea; Merritt, T Allen; Solomon, Tabitha; McNamara, Patrick; Jain, Amish; Singh, Jaideep; Chu, Alison; Noori, Shahab; Sekar, Krishnamurthy; Lavoie, Pascal M; Attridge, Joshua T; Swanson, Jonathan R; Gillam-Krakauer, Maria; Reese, Jeff; DeMauro, Sara; Poindexter, Brenda; Aucott, Sue; Satpute, Monique; Fernandez, Erika; Auchus, Richard J

2014-06-01

To test the hypothesis that an impaired adrenal response to stress might play a role in the hypotension that follows patent ductus arteriosus (PDA) ligation. We performed a multicenter study of infants born at <32 weeks' gestation who were about to undergo PDA ligation. Serum adrenal steroids were measured 3 times: before and after a cosyntropin (1.0 μg/kg) stimulation test (performed before the ligation), and at 10-12 hours after the ligation. A standardized approach for diagnosis and treatment of postoperative hypotension was followed at each site. A modified inotrope score (1 × dopamine [μg/kg/min] + 1 × dobutamine) was used to monitor the catecholamine support an infant received. Infants were considered to have catecholamine-resistant hypotension if their greatest inotrope score was >15. Of 95 infants enrolled, 43 (45%) developed hypotension and 14 (15%) developed catecholamine-resistant hypotension. Low postoperative cortisol levels were not associated with the overall incidence of hypotension after ligation. However, low cortisol levels were associated with the refractoriness of the hypotension to catecholamine treatment. In a multivariate analysis: the OR for developing catecholamine-resistant hypotension was OR 36.6, 95% CI 2.8-476, P = .006. Low cortisol levels (in infants with catecholamine-resistant hypotension) were not attributable to adrenal immaturity or impairment; their cortisol precursor concentrations were either low or unchanged, and their response to cosyntropin was similar to infants without catecholamine-resistant hypotension. Infants with low cortisol concentrations after PDA ligation are likely to develop postoperative catecholamine-resistant hypotension. We speculate that decreased adrenal stimulation, rather than an impaired adrenal response to stimulation, may account for the decreased production. Copyright © 2014 Elsevier Inc. All rights reserved.

Hypotension following patent ductus arteriosus ligation: the role of adrenal hormones

PubMed Central

Clyman, Ronald I.; Wickremasinghe, Andrea; Merritt, T. Allen; Solomon, Tabitha; McNamara, Patrick; Jain, Amish; Singh, Jaideep; Chu, Alison; Noori, Shahab; Sekar, Krishnamurthy; Lavoie, Pascal M.; Attridge, Joshua T.; Swanson, Jonathan R.; Gillam-Krakauer, Maria; Reese, Jeff; DeMauro, Sara; Poindexter, Brenda; Aucott, Sue; Satpute, Monique; Fernandez, Erika; Auchus, Richard J.

2014-01-01

Objective To test the hypothesis that an impaired adrenal response to stress might play a role in the hypotension that follows patent ductus arteriosus (PDA) ligation. Study design We performed a multicenter study of infants born at <32 weeks gestation who were about to undergo PDA ligation. Serum adrenal steroids were measured three times: before and after a cosyntropin (1.0 microgram/kg) stimulation test (performed prior to the ligation), and at 10–12 hours after the ligation. A standardized approach for diagnosis and treatment of postoperative hypotension was followed at each site. A modified Inotrope Score (1 x dopamine (μg/kg/min) + 1 x dobutamine) was used to monitor the catecholamine support an infant received. Infants were considered to have catecholamine-resistant hypotension if their highest Inotrope Score was >15. Results Of 95 infants enrolled, 43 (45%) developed hypotension and 14 (15%) developed catecholamine-resistant hypotension. Low post-operative cortisol levels were not associated with the overall incidence of hypotension following ligation. However, low cortisol levels were associated with the refractoriness of the hypotension to catecholamine treatment. In a multivariate analysis: the odds ratio for developing catecholamine-resistant hypotension was OR=36.6, CI=2.8–476, p=0.006. Low cortisol levels (in infants with catecholamine-resistant hypotension) were not due to adrenal immaturity or impairment; their cortisol precursor concentrations were either low or unchanged and their response to cosyntropin was similar to infants without catecholamine-resistant hypotension. Conclusion Infants with low cortisol concentrations following PDA ligation are likely to develop postoperative catecholamine-resistant hypotension. We speculate that decreased adrenal stimulation, rather than an impaired adrenal response to stimulation, may account for the decreased production. PMID:24636853

Nonsteroidal anti-inflammatory administration and patent ductus arteriosus ligation, a survey of practice preferences at US children's hospitals.

PubMed

Slaughter, Jonathan L; Reagan, Patricia B; Bapat, Roopali V; Newman, Thomas B; Klebanoff, Mark A

2016-06-01

We surveyed neonatal leadership at 46 US children's hospitals via web-based survey to identify local preferences and concerns regarding indomethacin prophylaxis, nonsteroidal anti-inflammatory drug (NSAID) treatment, and patent ductus arteriosus (PDA) ligation. We received a 100 % survey response (N = 46). Practice guidelines for prophylactic indomethacin were reported at 28 % of NICUs, for NSAID treatment of PDA at 39 % and for surgical ligation at 27 %. Respondents noted intra-institutional practice variation for indomethacin prophylaxis (33 %), NSAID treatment (70 %), and PDA ligation (73 %). The majority of institutions did not prescribe indomethacin prophylaxis (72 %). For PDA treatment, indomethacin was preferred over ibuprofen (80 %). We validated our survey results via comparison with billing data as documented in the Pediatric Health Information System (PHIS) database, finding that survey responses directly correlated with local billing data (p < 0.0001). At institutions that did not typically administer NSAIDs for PDA closure or surgical PDA ligation, a lack of evidence for their effectiveness in improving long-term outcomes and the risk of treatment-associated adverse effects were the most often cited reasons. No consensus exists among providers at US children's hospitals regarding prophylactic indomethacin, NSAID treatment, or PDA ligation. Lack of evidence and safety concerns play a prominent role. • NSAIDs and surgical PDA ligation are efficacious in preventing intraventricular hemorrhage (IVH) and closing PDA in preterm infants, but have not been shown to improve long-term respiratory, neurodevelopmental, or mortality outcomes. What is New: • Practice preferences for indomethacin prophylaxis, NSAID, and surgical PDA treatment vary both among and within institutions. Lack of treatment effectiveness and the risk of adverse effects are major concerns.

Does the number of veins ligated during varicococele surgery influence post-operative semen and hormone results?

PubMed

Majzoub, A; Elbardisi, H; Arafa, M; Agarwal, A; Al Said, S; Al Rumaihi, K

2016-09-01

Varicocele is a well-established cause of male subfertility, which is directly proportional to its clinical grade. Although newer ultrasonic grading systems have taken into account the existence of pampiniform venous plexi, little is known about the clinical significance of the number of veins ligated during surgery. Very few undersized studies reported an influence which triggered the need to evaluate such association. This is a retrospective study of 378 patients who underwent left microsurgical subinguinal varicocoelectomy. Semen analyses and blood hormone studies performed pre-operatively were compared to those executed 6 months after surgery. Patients were divided into abnormal semen and normal semen groups based on their initial semen results. They were also subdivided according to the number of veins ligated intraoperatively into three groups: <5, 5-10, and >10 veins. Sperm count, total motility, and progressive motility were significantly increased in 62, 60.3, and 53.3% of patients post-operatively (p = 0.001), respectively. No significant differences in hormone levels were detected overall. Of the 378 patients, 332 had an abnormal semen analysis, while the remaining 46 patients had a normal result. Sperm count, total motility, and progressive motility significantly increased after varicocoelectomy in patients with an abnormal initial semen analysis (p = 0.001). In 48.7% of patients, 5-10 veins were ligated during surgery, whereas 28.3% had >10 and 23% had <5 ligated veins. No statistically significant differences were noted in the initial or the follow-up results among the number of vein subgroups. Varicocele ligation improves patients' fertility potential. This improvement, however, is not influenced by the number of veins ligated intraoperatively. Clinical grading maintains its superiority in the evaluation of varicocele patients. © 2016 American Society of Andrology and European Academy of Andrology.

PPAR-alpha agonist treatment increases trefoil factor family-3 expression and attenuates apoptosis in the liver tissue of bile duct-ligated rats.

PubMed

Karakan, Tarkan; Kerem, Mustafa; Cindoruk, Mehmet; Engin, Doruk; Alper, Murat; Akın, Okan

2013-01-01

Peroxisome proliferators-activated receptor alpha activation modulates cholesterol metabolism and suppresses bile acid synthesis. The trefoil factor family comprises mucin-associated proteins that increase the viscosity of mucins and help protect epithelial linings from insults. We evaluated the effect of short-term administration of fenofibrate, a peroxisome proliferators activated receptor alpha agonist, on trefoil factor family-3 expression, degree of apoptosis, generation of free radicals, and levels of proinflammatory cytokines in the liver tissue of bile duct-ligated rats. Forty male Wistar rats were randomly divided into four groups: 1 = sham operated, 2 = bile duct ligation, 3 = bile duct-ligated + vehicle (gum Arabic), and 4 = bile duct-ligated + fenofibrate (100 mg/kg/day). All rats were sacrificed on the 7 th day after obtaining blood samples and liver tissue. Liver function tests, tumor necrosis factor-alpha and interleukin 1 beta in serum, and trefoil factor family-3 mRNA expression, degree of apoptosis (TUNEL) and tissue malondialdehyde (malondialdehyde, end-product of lipid peroxidation by reactive oxygen species) in liver tissue were evaluated. Fenofibrate administration significantly reduced serum total bilirubin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, and tumor necrosis factor-alpha and interleukin-1β levels. Apoptosis and malondialdehyde were significantly reduced in the fenofibrate group. Trefoil factor family-3 expression increased with fenofibrate treatment in bile duct-ligated rats. The peroxisome proliferators-activated receptor alpha agonist fenofibrate significantly increased trefoil factor family-3 expression and decreased apoptosis and lipid peroxidation in the liver and attenuated serum levels of proinflammatory cytokines in bile duct-ligated rats. Further studies are needed to determine the protective role of fenofibrate in human cholestatic disorders.

The incidence of complications associated with loop duodeno-ileostomy after single-anastomosis duodenal switch procedures among 1328 patients: a multicenter experience.

PubMed

Surve, Amit; Cottam, Daniel; Sanchez-Pernaute, Andres; Torres, Antonio; Roller, Joshua; Kwon, Yong; Mourot, Joshua; Schniederjan, Bleu; Neichoy, Bo; Enochs, Paul; Tyner, Michael; Bruce, Jon; Bovard, Scott; Roslin, Mitchell; Jawad, Muhammad; Teixeira, Andre; Srikanth, Myur; Free, Jason; Zaveri, Hinali; Pilati, David; Bull, Jamie; Belnap, LeGrand; Richards, Christina; Medlin, Walter; Moon, Rena; Cottam, Austin; Sabrudin, Sarah; Cottam, Samuel; Dhorepatil, Aneesh

2018-02-02

The single-anastomosis duodenal switch procedure is a type of duodenal switch that involves a loop anastomosis rather than traditional Roux-en-Y reconstruction. To date, there have been no multicenter studies looking at the complications associated with post-pyloric loop reconstruction. The aim of the study was to report the incidence of complications associated with loop duodeno-ileostomy (DI) following single-anastomosis duodenal switch (SADS) procedures. Mixed of private and teaching facilities. The medical records of 1328 patients who underwent primary SADS procedure (single-anastomosis duodeno-ileal bypass with sleeve gastrectomy or stomach intestinal pylorus-sparing surgery) by 17 surgeons from 3 countries (United States, Spain, and Australia) at 9 centers over a 6-year period were retrospectively reviewed, and their results were compared with articles in the literature. Mean preoperative body mass index was 51.6 kg/m 2 . Of 1328 patients, 123 patients received a linear stapled duodeno-ileostomy (DI) and 1205 patients a hand-sewn DI. In the overall series, the anastomotic leak, ulcer, and bile reflux occurred in .6% (9/1328), .1% (2/1328), and .1% (2/1328), respectively. None of our patients experienced volvulus at the DI or an internal hernia. Overall, 5 patients (.3%) (3/123 [2.4%] with linear stapled DI versus 2/1205 [.1%] with hand-sewn DI [P<.05]) experienced stricture at the DI in this series. The overall incidence of complications associated with loop DI was lower than the reported incidence of anastomotic complications after Roux-en-Y gastric bypass and biliopancreatic diversion with duodenal switch. SADS procedures may cause much fewer anastomotic complications compared with Roux-en-Y gastric bypass and biliopancreatic diversion with duodenal switch. Copyright © 2018 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Ostomy-related complications after emergent abdominal surgery: a 2-year follow-up study.

PubMed

Lindholm, Elisabet; Persson, Eva; Carlsson, Eva; Hallén, Anne-Marie; Fingren, Jeanette; Berndtsson, Ina

2013-01-01

The aim of this study was to prospectively evaluate ostomy-related complications and describe ostomy configuration in patients undergoing acute abdominal surgery. The study sample comprised 144 patients with a median age of 67 years (IOR: 53.5-78 years) who underwent an intestinal ostomy as part of an acute abdominal surgical procedure. The research setting was the surgical and gynecological clinics at the Sahlgrenska University Hospital in Gothenburg, Sweden. Ostomy configuration, diameter, height, and the presence of stomal and peristomal complications were assessed by a WOC nurse 1 to 2 times while in hospital, once at the ostomy outpatient clinic 2 weeks after discharge, and at 3, 6, 12, and 24 months following ostomy creation. The types of ostomies evaluated were end colostomy (58%), end ileostomy (18%), loop ileostomy (17%), and loop colostomy (7%). Most stomal or peristomal complications occurred within 1 year after surgery (31 of 57; 54.4%). Necrosis, separation, and stenosis were most common in patients with an end colostomy. Peristomal skin complications occurred in 45% of subjects during the first 6 months after surgery. The ostomy's diameter decreased significantly during the hospital course and over the first 2 weeks following hospital discharge in patients with end colostomy (P< .0001), end ileostomy (P< .0081), loop ileostomy (P= .008), and loop colostomy (ns). Patients with a low ostomy had peristomal skin problems ranging between 21% and 57% over this time period. The frequency of using a pouching system that incorporated convexity was highest in the case of loop ileostomy, used in 67% at 6 months. During the first 2 weeks after discharge, the physical configuration of the ostomy evolves and the pouching system must be frequently adjusted by a WOC nurse. Stomal and peristomal complications are prevalent during the first 2 postoperative years and especially during the first 6 months.

Effect of L-cysteine on remote organ injury in rats with severe acute pancreatitis induced by bile-pancreatic duct obstruction.

PubMed

Yang, Li-Juan; Wan, Rong; Shen, Jia-Qing; Shen, Jie; Wang, Xing-Peng

2013-08-01

Remote organ failure occurs in cases of acute pancreatitis (AP); however, the reports on AP induced by pancreatic duct obstruction are rare. In this study we determined the effect of L-cysteine on pancreaticobiliary inflammation and remote organ damage in rats after pancreaticobiliary duct ligation (PBDL). AP was induced by PBDL in rats with 5/0 silk. Sixty rats were randomly divided into 4 groups. Groups A and B were sham-operated groups that received injections of saline or L-cysteine (10 mg/kg) intraperitoneally (15 rats in each group). Groups C and D were PBDL groups that received injections of saline or L-cysteine (10 mg/kg) intraperitoneally (15 rats in each group). The tissue samples of the pancreas and remote organs such as the lung, liver, intestine and kidney were subsequently examined for pathological changes under a light microscope. The samples were also stored for the determination of malondialdehyde and glutathione levels. Blood urea nitrogen (BUN), plasma amylase, ALT and AST levels were determined spectrophotometrically using an automated analyzer. Also, we evaluated the effect of L-cysteine on remote organ injury in rats with AP induced by retrograde infusion of 3.5% sodium taurocholate (NaTc) into the bile-pancreatic duct. Varying degrees of injury in the pancreas, lung, liver, intestine and kidney were observed in the rats 24 hours after PBDL. The severity of injury to the lung, liver and intestine was attenuated, while injury status was not changed significantly in the pancreas and kidney after L-cysteine treatment. Oxidative stress was also affected by L-cysteine in PBDL-treated rats. The concentration of tissue malondialdehyde decreased in the pancreas and remote organs of PBDL and L-cysteine administrated rats, and the concentration of glutathione increased more significantly than that of the model control group. However, L-cysteine administration reduced the severity of injury in remote organs but not in the pancreas in rats with NaTc-induced AP. L-cysteine treatment attenuated multiple organ damage at an early stage of AP in rats and modulated the oxidant/antioxidant imbalance.

Formation and rearrangement of homoserine depsipeptides and depsiproteins in the α-ketoacid-hydroxylamine ligation with 5-oxaproline.

PubMed

Wucherpfennig, Thomas G; Rohrbacher, Florian; Pattabiraman, Vijaya R; Bode, Jeffrey W

2014-11-03

The primary products of the chemical ligation of α-ketoacids and 5-oxaproline peptides are esters, rather than the previously reported amides. The depsipeptide product rapidly rearranges to the amide in basic buffers. The formation of esters sheds light on possible mechanisms for the type II KAHA ligations and opens an avenue for the chemical synthesis of depsiproteins. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of common vaginal tunic ligation during field castration in draught colts.

PubMed

Carmalt, J L; Shoemaker, R W; Wilson, D G

2008-09-01

The objective of this study was to determine if ligation of the common vaginal tunic could prevent or reduce the incidence of omental herniation and eventration in draught colts undergoing routine field castration. It was found that common vaginal tunic ligation, while not completely preventing omental herniation and evisceration, significantly reduced the incidence of these complications and should be considered in those males deemed at increased risk of significant post castration complications.

Alterations in plaque accumulation and gingival inflammation promoted by treatment with self-ligating and conventional orthodontic brackets

PubMed Central

Cardoso, Mauricio de Almeida; Saraiva, Patrícia Pinto; Maltagliati, Liliana Ávila; Rhoden, Fernando Kleinübing; Costa, Carla Cristina Alvarenga; Normando, David; Capelozza, Leopoldino

2015-01-01

OBJECTIVE: The aim of the present study was to evaluate, comparatively, the periodontal response during orthodontic treatment performed with self-ligating and conventional brackets. METHODS: Sixteen Caucasian individuals of both sexes, aged between 12 and 16 years old and in permanent dentition were selected. Eight individuals were treated with conventional brackets installed on the lower dental arch and self-ligating brackets on the upper arch. Another eight individuals received self-ligating brackets in the lower arch and conventional brackets in the upper arch. The subjects received material and instructions for oral hygiene. Visible plaque index (VPI), gingival bleeding index (GBI) and clinical attachment level (CAL) were evaluated just after installation of orthodontic appliances, and 30, 60 and 180 days later. Mann-Whitney test was used to compare differences between groups (self-ligating and conventional), two-way ANOVA followed by Tukey's test was used to assess CAL at each site of each tooth. Significance level was set at 5%. RESULTS: No significant changes were found with regard to the assessed parameters (VPI, GBI and CAL) in either one of the systems. CONCLUSION: No significant changes were found with regard to the periodontal response to orthodontic treatment for the variables assessed and between subjects receiving passive self-ligating and conventional brackets. All individuals had received oral hygiene instructions and had their periodontal conditions monitored. PMID:25992985

Outcomes of neonatal patent ductus arteriosus ligation in Canadian neonatal units with and without pediatric cardiac surgery programs.

PubMed

Wong, Charles; Mak, Michael; Shivananda, Sandesh; Yang, Junmin; Shah, Prakeshkumar S; Seidlitz, Wendy; Pemberton, Julia; Fitzgerald, Peter G; Cameron, Brian H

2013-05-01

Preterm infants needing patent ductus arteriosus (PDA) ligation are transferred to a pediatric cardiac center (CC) unless the operation can be done locally by a pediatric surgeon at a non-cardiac center (NCC). We compared infant outcomes after PDA ligation at CC and NCC. We analyzed 990 preterm infants who had PDA ligation between 2005 and 2009 using the Canadian Neonatal Network database. In-hospital mortality and major morbidities were compared between CC (n=18) and NCC (n=9). SNAP-II-adjusted mortality rates were similar (CC=8.7% vs NCC=10.7%, P=.32). Significant cranial ultrasound abnormalities (CC=24.1% vs NCC=32.1%, P<.01) and culture-proven sepsis (CC=39.7% vs NCC=54.8%, P<.01) were more frequent in infants treated at NCC. Infants transferred to CC had higher rates of cranial ultrasound abnormalities (transferred 31.6% vs non-transferred 20.4%, P<.01). NSAIDs prior to PDA ligation were used more often at NCC (CC 36.6% vs NCC 75.6%, P<.001). Mortality rates after PDA ligation were similar at CC and NCC, but cranial ultrasound abnormalities and sepsis rates were higher at NCC. Higher morbidity may be associated with different PDA management strategies, including NSAID use or infant transfer. Further studies are needed to investigate the reasons for these differences in morbidity. Copyright © 2013 Elsevier Inc. All rights reserved.

Unilateral vocal fold paralysis in premature infants after ligation of patent ductus arteriosus: vascular clip versus suture ligature.

PubMed

Spanos, William C; Brookes, James T; Smith, Mark C; Burkhart, Harold M; Bell, Edward F; Smith, Richard J H

2009-10-01

We investigated risk factors associated with unilateral iatrogenic vocal fold paralysis (IVFP) in the context of ligation of patent ductus arteriosus (PDA) and compared the rates of paralysis between vascular clip and suture ligation procedures. We performed a prospective examination of infants with isolated PDA treated surgically during 1995 to 2005. Statistical significance was determined with a 2-tailed t-test. Of 68 PDA ligations, 13 cases of left-sided IVFP were diagnosed, for an overall incidence of 19%. All cases of IVFP occurred in 55 infants who weighed less than 1 kg at birth. Suture ligature was used in 60% of all PDA ligation patients, and vascular clips in 40%. The incidence of IVFP in patients with vascular clips (19%) was similar to the incidence in those with suture ligature (20%). Hoarseness or stridor was present in 69% of patients with IVFP, compared to 17% of normal controls (p <0.001). The rate of aspiration was not increased in the IVFP group; however, 15% of the patients with IVFP had episodes of decreased oxygen saturation, versus 7% of infants with normal vocal fold mobility. A hoarse infant with a birth weight of less than 1 kg who has undergone PDA ligation should be examined for unilateral IVFP. Vascular clips and suture ligature are associated with similar rates of IVFP.

Coated Rectangular Composite Archwires: A Comparison Of Self-Ligating And Conventional Bracket Systems During Sliding Mechanics

NASA Astrophysics Data System (ADS)

Woods, David Keith

The purpose of this study was to analyze the resistance to sliding of coated rectangular fiber reinforced composite archwires using various brackets systems and second-order bracket angulations. Resistance to sliding was investigated for eight bracket systems: six self-ligating brackets (four passive and two passive-active) and two conventional brackets. A rectangular fiber reinforced composite archwire of 0.019 x 0.025-in dimension from BiomersRTM SimpliClear was drawn through a three-bracket model system at ten millimeters per minute for 2.5 millimeters. For each bracket, the resistance to sliding was measured at four bracket angulations (0°, 2.5°, 5°, and 10°) in a dry state at room temperature. The fiber reinforced composite archwire produced the lowest sliding resistance with the passive self-ligating bracket system (Damon DQ) at each bracket angulation tested. Overall, self-ligating bracket systems generated lower sliding resistance than conventionally ligated systems, and one passive/active self-ligating bracket system (In-Ovation-R). There was a significant increase in resistance to sliding as bracket angulation increased for all bracket systems tested. Microscopic analysis revealed increased perforation of the archwire coating material as bracket angulations were increased. Our findings show that the rectangular fiber reinforced composite archwire may be acceptable for sliding mechanics during the intermediate stages of orthodontic tooth movement, however more long-term studies are needed.

Alterations in plaque accumulation and gingival inflammation promoted by treatment with self-ligating and conventional orthodontic brackets.

PubMed

Cardoso, Mauricio de Almeida; Saraiva, Patrícia Pinto; Maltagliati, Liliana Ávila; Rhoden, Fernando Kleinübing; Costa, Carla Cristina Alvarenga; Normando, David; Capelozza Filho, Leopoldino

2015-01-01

The aim of the present study was to evaluate, comparatively, the periodontal response during orthodontic treatment performed with self-ligating and conventional brackets. Sixteen Caucasian individuals of both sexes, aged between 12 and 16 years old and in permanent dentition were selected. Eight individuals were treated with conventional brackets installed on the lower dental arch and self-ligating brackets on the upper arch. Another eight individuals received self-ligating brackets in the lower arch and conventional brackets in the upper arch. The subjects received material and instructions for oral hygiene. Visible plaque index (VPI), gingival bleeding index (GBI) and clinical attachment level (CAL) were evaluated just after installation of orthodontic appliances, and 30, 60 and 180 days later. Mann-Whitney test was used to compare differences between groups (self-ligating and conventional), two-way ANOVA followed by Tukey's test was used to assess CAL at each site of each tooth. Significance level was set at 5%. No significant changes were found with regard to the assessed parameters (VPI, GBI and CAL) in either one of the systems. No significant changes were found with regard to the periodontal response to orthodontic treatment for the variables assessed and between subjects receiving passive self-ligating and conventional brackets. All individuals had received oral hygiene instructions and had their periodontal conditions monitored.

Usefulness of real-time elastography strain ratio in the assessment of bile duct ligation-induced liver injury and the hepatoprotective effect of chitosan: an experimental animal study.

PubMed

Dudea, Marina; Clichici, Simona; Olteanu, Diana Elena; Nagy, Andras; Cucoş, Maria; Dudea, Sorin

2015-01-01

The purpose of the study described here was to evaluate the usefulness of the elastographic strain ratio in the assessment of liver changes in an experimental animal setting and the hepatoprotective effects of chitosan. Ultrasonography and Strain Ratio calculation were performed before and after bile duct ligation (BDL) in three groups of Wistar albino rats (n = 10 animals per group): (i) rats subjected to bile duct ligation only; (ii) rats subjected to bile duct ligation and administered chitosan for 14 d; (iii) rats subjected to bile duct ligation and administered chitosan for 7 d. The results were compared with the laboratory data and pathologic findings. Strain ratios revealed an increase in liver stiffness after bile duct ligation (p < 0.05), except in the group with chitosan administered for 7 d, and agreed with laboratory and pathology data. In conclusion, strain ratio can be used as an experimental research instrument in the assessment of liver response to injury. To the best of our knowledge, this is the first study reporting on the usefulness of the sonoelastographic liver-to-kidney strain ratio in assessing the effects of experimentally induced liver lesions. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Outcomes of Left Ventricular Function According to Treatment Response for a Patent Ductus Arteriosus in Preterm Infants.

PubMed

Kang, Soo Jung; Cho, Young Sun; Hwang, Seo Jung; Kim, Hyo Jin

2017-12-01

To evaluate the outcomes of left ventricular (LV) function according to treatment response for a hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants. Echocardiograms of 21 preterm infants born at gestational age < 31 weeks obtained at term-equivalent age were retrospectively studied. Among preterm infants with a hsPDA, 9 underwent ligation after failure of pharmacological closure (ligation group) and 6 experienced successful pharmacological closure (medication group). Six preterm infants without hsPDA (no-hsPDA group) were studied as controls. LV peak longitudinal systolic strain (ε) of each infant was retrospectively obtained from echocardiograms using velocity vector imaging, along with neonatal outcomes. Pharmacological closures were attempted at postnatal day 2-3. In the ligation group, the median postnatal age at ligation was 20 days. In the ligation group, LV peak longitudinal systolic ε was significantly decreased at term-equivalent age compared to the other groups. Between the medication and no-hsPDA groups, LV peak longitudinal systolic ε did not differ significantly. Among the neonatal outcomes, infants who experienced necrotizing enterocolitis (NEC) showed significantly decreased LV peak longitudinal systolic ε compared to the infants who did not experience NEC . We speculate that in preterm infants with an hsPDA, in cases of medical treatment failure, early PDA ligation at less than 20 days of postnatal age would be beneficial for preserving LV systolic function.

Surgical management of a patent ductus arteriosus: Is this still an option?

PubMed

Weisz, Dany E; Giesinger, Regan E

2018-03-07

The evolution of neonatal intensive care over the past decade has seen the role of surgical patent ductus arteriosus (PDA) ligation in preterm infants both decrease in scope and become laden with uncertainty. Associations of ligation with adverse neonatal and neurodevelopmental outcomes have rendered the ligation decision more challenging for clinicians and have been associated with a decline in surgical treatment, but these findings may be due to bias from confounding by indication in observational studies rather than a causal detrimental effect of ligation. Accordingly, ligation may still be indicated for infants with large ductal shunts and moderate-severe respiratory insufficiency in whom the prospect of timely spontaneous closure appears low. Ultimately a randomized trial of surgical ligation versus conservative management is necessary to assess the efficacy of this invasive intervention in a population of extremely preterm infants with large ductal shunts. Simultaneously, the transcatheter approach to ductal closure in the very immature infant represents an exciting therapeutic alternative but which is still in its infancy. Insights into the pathophysiology of postoperative cardiorespiratory deterioration, including the importance of left ventricular afterload, may help clinicians avoid instability and mitigate a potentially injurious aspect of surgical treatment. This review examines the evidence regarding the benefits and risks of PDA surgery in preterm neonates and provides a pathophysiology-based management paradigm to guide perioperative care in high-risk infants. © 2018 Published by Elsevier Ltd.

Cosilencing Intestinal Transglutaminase-2 and Interleukin-15 Using Gelatin-Based Nanoparticles in an in Vitro Model of Celiac Disease.

PubMed

Attarwala, Husain; Clausen, Valerie; Chaturvedi, Prasoon; Amiji, Mansoor M

2017-09-05

In this study, we have developed a type B gelatin nanoparticle based siRNA delivery system for silencing of intestinal transglutaminase-2 (TG2) and interleukin-15 (IL-15) genes in cultured human intestinal epithelial cells (Caco-2) and murine alveolar macrophage cells (J774A.1). Small interfering RNA (siRNA) targeting the TG2 or IL-15 gene was encapsulated within gelatin nanoparticles using ethanol-water solvent displacement method. Size, charge, and morphology of gelatin nanoparticles were evaluated using a Zetasizer instrument and transmission electron microscopy. siRNA encapsulation efficiency was determined using an siRNA specific stem-loop quantitative polymerase chain reaction (qPCR) assay. Cellular uptake of siRNA-containing gelatin nanoparticles was determined using fluorescent microscopy and stem-loop qPCR assay. siRNA loading in the RISC (RNA-induced silencing complex) was determined by immunoprecipitation of argonaute 2 (AGO2) protein followed by stem-loop qPCR for siRNA quantification. Gene expression analysis of TG2, IL-15, and the proinflammatory cytokines, tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ), was performed using qPCR assays. Efficacy of silencing TG2 and IL-15 knockdown was evaluated in an in vitro model of celiac disease by utilizing immunogenic α-gliadin peptide p31-43 in cultured J774A.1 cells. siRNA-containing gelatin nanoparticles were spherical in shape with mean particle size and charge of 217 ± 8.39 nm and -6.2 ± 0.95 mV, respectively. siRNA loading efficiency within gelatin nanoparticles was found to be 89.3 ± 3.05%. Evaluations of cellular uptake using fluorescent microscopy showed rapid internalization of gelatin nanoparticles within 2 h of dosing, with cytosolic localization of delivered siRNA in Caco-2 cells. Gelatin nanoparticles showed greater intracellular siRNA exposure with a longer half-life, when compared to Lipofectamine-mediated siRNA delivery. Approximately 0.1% of total intracellular siRNA was associated in the RISC complex. A maximum knockdown of 60% was observed at 72 h post siRNA treatment for both TG2 and IL-15 genes, which corresponded to ∼200 copies of RISC associated siRNA. Further, efficacy of gelatin nanoparticle mediated knockdown of TG2 and IL-15 mRNA was tested in an in vitro model of celiac disease. Significant suppression in the levels of proinflammatory cytokines (TNF-α and IFN-γ) was observed in p31-43 stimulated J774A.1 cells upon either IL-15 or IL-15 + TG2 siRNA treatment. The results from this study indicate that gelatin nanoparticle mediated TG2 and IL-15 siRNA gene silencing is a very promising approach for the treatment of celiac disease.

Late medical therapy of patent ductus arteriosus using intravenous paracetamol.

PubMed

EL-Khuffash, Afif; James, Adam T; Cleary, Aoife; Semberova, Jana; Franklin, Orla; Miletin, Jan

2015-05-01

To investigate the effect of late treatment with intravenous paracetamol on patent ductus arteriosus (PDA) closure prior to possible PDA ligation. A retrospective review of infants with a haemodynamically significant PDA, considered for PDA ligation and treated with intravenous paracetamol prior to possible ligation. Thirty six infants with a median gestation of 26.1 weeks received paracetamol at a median age of 27 days. Paracetamol was associated with immediate closure in nine (25%) infants. There was no response to paracetamol treatment in four (11%) infants who subsequently underwent a PDA ligation. In 23 (64%) infants, the PDA constricted and all but one of this group demonstrated complete PDA closure prior to discharge. There may be a role for intravenous paracetamol in late closure of infants with a significant PDA to avoid ligation. The use of paracetamol for late treatment of PDA should be systematically evaluated. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Evaluation of the force generated by gradual deflection of orthodontic wires in conventional metallic, esthetic, and self-ligating brackets

PubMed Central

Francisconi, Manoela Fávaro; Janson, Guilherme; Henriques, José Fernando Castanha; de Freitas, Karina Maria Salvatore

2016-01-01

ABSTRACT Objective: The purpose of this study was to evaluate the deflection forces of Nitinol orthodontic wires placed in different types of brackets: metallic, reinforced polycarbonate with metallic slots, sapphire, passive and active self-ligating, by assessing strength values variation according to gradual increase in wire diameter and deflection and comparing different combinations in the different deflections. Material and Methods: Specimens were set in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using the ISO 15841 protocol. Data were subjected to One-way ANOVA, followed by Tukey tests (p<0.05). Results: Self-ligating brackets presented the most similar behavior to each other. For conventional brackets there was no consistent behavior for any of the deflections studied. Conclusions: Self-ligating brackets presented the most consistent and predictable results while conventional brackets, as esthetic brackets, showed very different patterns of forces. Self-ligating brackets showed higher strength in all deflections when compared with the others, in 0.020-inch wires. PMID:27812620

Management of penetrating carotid arterial injury.

PubMed Central

Liekweg, W G; Greenfield, L J

1978-01-01

A review of the experience with penetrating wounds to the carotid artery was undertaken in an effort to establish concise clinical criteria for surgical management. These results were compared with similar cases from the literature reported since 1963. In these 233 cases, the presence or absence of preoperative neurological deficits was correlated with vascular repair or ligation of the carotid artery. The presence of coma preoperatively was the single most influential factor in determining operative management and prognosis. Patients without a neurological defect should have restoration of vascular continuity (0% mortality, 0.6% morbidity), which produces significantly better results than carotid ligation (p less than 0.002). Patients with all grades of neurological deficit, short of coma, should also have primary vascular repair. Morbidity and mortality rates are significantly less than those following ligation (15 vs. 50%, p less than 0.05). In comatose patients, neither repair nor ligation appear to influence the poor prognosis. At the present time, ligation of the carotid artery is only indicated in the comatose patient who has no evidence of prograde flow or if repair is technically impossible. PMID:718284

Superficial Dorsal Vein Injury/Thrombosis Presenting as False Penile Fracture Requiring Dorsal Venous Ligation

PubMed Central

Rafiei, Arash; Hakky, Tariq S; Martinez, Daniel; Parker, Justin; Carrion, Rafael

2014-01-01

Introduction Conditions mimicking penile fracture are extremely rare and have been seldom described. Aim To describe a patient with false penile fracture who presented with superficial dorsal vein injury/thrombosis managed with ligation. Methods A 33-year-old male presented with penile swelling and ecchymosis after intercourse. A penile ultrasound demonstrated a thrombosed superficial dorsal vein but also questionable fracture of the tunica albuginea. As the thrombus was expanding, he was emergently taken to the operating room for exploration and required only dorsal venous ligation. Results Postoperatively, patient's Sexual Health Inventory for Men score was 23, and he had no issues with erections or sexual intercourse. Conclusion Early exploration of patients with suspected penile fracture provides excellent results with maintenance of erectile function. Also, in the setting of dorsal vein thrombosis, ligation preserves the integrity of the penile tissues and avoids unnecessary complications from conservative management. Rafiei A, Hakky TS, Martinez D, Parker J, and Carrion R. Superficial dorsal vein injury/thrombosis presenting as false penile fracture requiring dorsal venous ligation. PMID:25548650

Does a surgical simulator improve resident operative performance of laparoscopic tubal ligation?

PubMed

Banks, Erika H; Chudnoff, Scott; Karmin, Ira; Wang, Cuiling; Pardanani, Setul

2007-11-01

The purpose of this study was to assess whether a surgical skills simulator laboratory improves resident knowledge and operative performance of laparoscopic tubal ligation. Twenty postgraduate year 1 residents were assigned randomly to either a surgical simulator laboratory on laparoscopic tubal ligation together with apprenticeship teaching in the operating room or to apprenticeship teaching alone. Tests that were given before and after the training assessed basic knowledge. Attending physicians who were blinded to resident randomization status evaluated postgraduate year 1 performance on a laparoscopic tubal ligation in the operating room with 3 validated tools: a task-specific checklist, global rating scale, and pass/fail grade. Postgraduate year 1 residents who were assigned randomly to the surgical simulator laboratory performed significantly better than control subjects on all 3 surgical assessment tools (the checklist, the global score, and the pass/fail analysis) and scored significantly better on the knowledge posttest (all P < .0005). Compared with apprenticeship teaching alone, a surgical simulator laboratory on laparoscopic tubal ligation improved resident knowledge and performance in the operating room.

Chemical Synthesis of the 20 kDa Heme Protein Nitrophorin 4 by α-Ketoacid-Hydroxylamine (KAHA) Ligation.

PubMed

He, Chunmao; Kulkarni, Sameer S; Thuaud, Frédéric; Bode, Jeffrey W

2015-10-26

The chemical synthesis of the 184-residue ferric heme-binding protein nitrophorin 4 was accomplished by sequential couplings of five unprotected peptide segments using α-ketoacid-hydroxylamine (KAHA) ligation reactions. The fully assembled protein was folded to its native structure and coordinated to the ferric heme b cofactor. The synthetic holoprotein, despite four homoserine residues at the ligation sites, showed identical properties to the wild-type protein in nitric oxide binding and nitrite dismutase reactivity. This work establishes the KAHA ligation as a valuable and viable approach for the chemical synthesis of proteins up to 20 kDa and demonstrates that it is well-suited for the preparation of hydrophobic protein targets. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gross morphology and histology of the alimentary tract of the convict cichlid Amatitlania nigrofasciata.

PubMed

Hopperdietzel, C; Hirschberg, R M; Hünigen, H; Wolter, J; Richardson, K; Plendl, J

2014-11-01

The primary objectives of this study were to document the macroscopic and histological structure of the alimentary tract (AT) of the convict cichlid Amatitlania nigrofasciata, because there are no data available for this omnivorous freshwater fish of the family Cichlidae. The morphology of the AT of A. nigrofasciata resembles that of related species. While having morphological criteria of the AT typical of most omnivorous fishes, such as a blind sac stomach and medium length intestine, A. nigrofasciata also has some structural peculiarities: the oesophagus is lined by a uniform stratified squamous epithelial layer with interspersed goblet cells along its entire length. Additionally, it has well-developed layers of the tunica muscularis including muscle fibre bundles that ascend into its mucosal folds. Occasionally, taste buds are present. In the transitional area between oesophagus and stomach, a prominent torus-like closure device is present. The mucosa of the stomach cannot be divided into different regions according to mucosal and morphological properties. The simple pattern of intestinal loops of A. nigrofasciata has few variations, irrespective of sex, mass and length of the individual fish. The first segment of the intestine is characterized by the largest mucososerosal ratio and the most complex mucosal surface architecture. A distinction of midgut and hindgut was not possible in A. nigrofasciata due to lack of defining structural components as described for other fish species. © 2014 The Fisheries Society of the British Isles.

Pilot study of bipolar radiofrequency-induced anastomotic thermofusion-exploration of therapy parameters ex vivo.

PubMed

Winter, Hanno; Holmer, Christoph; Buhr, Heinz-Johannes; Lindner, Gerd; Lauster, Roland; Kraft, Marc; Ritz, Jörg-Peter

2010-01-01

Vessel sealing has been well-established in surgical practice in recent years. Bipolar radiofrequency-induced thermofusion (BIRTH) of intestinal tissue might replace traditionally used staples or sutures in the near future. In this experimental study, the influence of compressive pressure, fusion temperature, and duration of heating on the quality of intestinal anastomosis was investigated to obtain the relevant major parameters for the in vivo use of this system. An experimental setup for a closed-loop temperature-controlled bipolar radiofrequency-induced thermofusion of porcine intestinal tissue was developed. Twenty-four colon samples were harvested from nine different Saalower-Kräuter pigs and then anastomosed altering compressive pressure on five different levels to explore its influence on anastomotic bursting pressure. The anastomotic bursting strength depends on the compressive pressure applied to the colonic fusion site. An optimal interval of compressive pressure (CP = 1.125 N/mm(2)) in respect of a high amount of burst pressure was detected. A correlation (r = 0.54, p = 0.015) of burst pressure to delta compression indicated that increasing colonic wall thickness probably strengthens the anastomotic fusion. This study is a first step to enlighten the major parameters of tissue fusion, though effects and interactions of various main parameters of bipolar radiofrequency-induced thermofusion of colonic tissue remain unclear. Further studies exploring the main effects and interactions of tissue and process parameters to the quality of the fusion site have to follow.

Selectivity of antagonists for the Cys-loop native receptors for ACh, 5-HT and GABA in guinea-pig myenteric neurons.

PubMed

Juárez, E H; Ochoa-Cortés, F; Miranda-Morales, M; Espinosa-Luna, R; Montaño, L M; Barajas-López, C

2014-01-01

The three most common Cys-loop receptors expressed by myenteric neurons are nACh, 5-HT3 and GABAA . To investigate the function of these proteins researchers have used channel inhibitors such as hexamethonium (antagonist of nACh receptors), ondansetron (antagonist of 5-HT3 receptors), picrotoxin and bicuculline (both antagonists of GABAA receptors). The aim of this study was to investigate the specificity of these inhibitors on Cys-loop receptors of primary cultured neurons obtained from the guinea-pig small intestine. The whole-cell configuration of the patch clamp techniques was used to record membrane currents induced by ACh (IACh ), 5-HT (I5-HT ) and GABA (IGABA ) in the absence and the presence of various concentrations of hexamethonium, ondansetron, picrotoxin or bicuculline. The three Cys-loop receptors present in enteric neurons are expressed independently and they do not cross-desensitized. Hexamethonium inhibited IACh without affecting I5-HT and IGABA . Ondansetron inhibited I5-HT and also IACh but did not affect IGABA . Picrotoxin and bicuculline inhibited I5-HT , IACh and IGABA with different potency, being the lowest potency on 5-HT3 receptors. All these inhibitory effects were concentration dependent and reversible. Our observations showed that except for hexamethonium, all other inhibitors used here show different degrees of selectivity, which has to be considered when these antagonists are used in experimental studies aimed to investigate the functions of these receptors. In particular, in tissues expressing nACh receptors because these are the targets of all other inhibitors used here. The low potency of picrotoxin and bicuculline to inhibit 5-HT3 receptors suggests that these receptors are heteromeric proteins. © 2013 John Wiley & Sons Ltd.

Chemical Synthesis of Proteins

PubMed Central

Nilsson, Bradley L.; Soellner, Matthew B.; Raines, Ronald T.

2010-01-01

Proteins have become accessible targets for chemical synthesis. The basic strategy is to use native chemical ligation, Staudinger ligation, or other orthogonal chemical reactions to couple synthetic peptides. The ligation reactions are compatible with a variety of solvents and proceed in solution or on a solid support. Chemical synthesis enables a level of control on protein composition that greatly exceeds that attainable with ribosome-mediated biosynthesis. Accordingly, the chemical synthesis of proteins is providing previously unattainable insight into the structure and function of proteins. PMID:15869385

Encoded Library Synthesis Using Chemical Ligation and the Discovery of sEH Inhibitors from a 334-Million Member Library

NASA Astrophysics Data System (ADS)

Litovchick, Alexander; Dumelin, Christoph E.; Habeshian, Sevan; Gikunju, Diana; Guié, Marie-Aude; Centrella, Paolo; Zhang, Ying; Sigel, Eric A.; Cuozzo, John W.; Keefe, Anthony D.; Clark, Matthew A.

2015-06-01

A chemical ligation method for construction of DNA-encoded small-molecule libraries has been developed. Taking advantage of the ability of the Klenow fragment of DNA polymerase to accept templates with triazole linkages in place of phosphodiesters, we have designed a strategy for chemically ligating oligonucleotide tags using cycloaddition chemistry. We have utilized this strategy in the construction and selection of a small molecule library, and successfully identified inhibitors of the enzyme soluble epoxide hydrolase.

Therapeutic mild hypothermia improves early outcomes in rats subjected to severe sepsis.

PubMed

Ding, Wu; Shen, Yuehong; Li, Qiang; Jiang, Shouyin; Shen, Huahao

2018-04-15

Therapeutic hypothermia has shown beneficial effects in sepsis. This study focused on its mechanism. Sixteen male Sprague-Dawley rats underwent cecal ligation and perforation and subsequently were treated with either hypothermia (HT; body temperature cooled and maintained at 34 °C by ice pad for 10 h; n = 8) or normothermia (NT; n = 8). Three additional rats underwent sham surgery. The body temperatures of the sham-operated and NT groups were maintained at 38 °C with a thermal pad. After the hypothermia treatment, the HT rats were rewarmed for 2 h. The groups were compared for circulating cytokines (IL-6, IL-10), lactate, high mobility group box-1 protein (HMGB1), and lung and intestinal lesions. Animals were observed for 24 h. Compared with the sham-operated group, the 2 sepsis group rats had significantly higher circulating IL-6, HMGB1, and lactate levels, and tissue injury. In the HT rats, the levels of IL-6, HMGB1, and lactate, the lung wet-to-dry ratio, and lung and intestinal damage were significantly lower than that of the NT group. Circulating IL-10 levels increased significantly after 12 h in the sepsis groups compared with sham animals, while that of the NT and HT groups were comparable. The survival rates of the NT and HT rats were also comparable. Therapeutic hypothermia in a rat model of sepsis was associated with lower levels of circulating IL-6 and HMGB1, and less capillary leakage and tissue edema. These results suggest that mild hypothermia has potential as a therapy in sepsis. Copyright © 2018 Elsevier Inc. All rights reserved.

Nuclear factor-E2-related factor 2 is a major determinant of bile acid homeostasis in the liver and intestine

PubMed Central

Weerachayaphorn, Jittima; Mennone, Albert; Soroka, Carol J.; Harry, Kathy; Hagey, Lee R.; Kensler, Thomas W.

2012-01-01

The transcription factor nuclear factor-E2-related factor 2 (Nrf2) is a key regulator for induction of hepatic detoxification and antioxidant mechanisms, as well as for certain hepatobiliary transporters. To examine the role of Nrf2 in bile acid homeostasis and cholestasis, we assessed the determinants of bile secretion and bile acid synthesis and transport before and after bile duct ligation (BDL) in Nrf2−/− mice. Our findings indicate reduced rates of biliary bile acid and GSH excretion, higher levels of intrahepatic bile acids, and decreased expression of regulators of bile acid synthesis, Cyp7a1 and Cyp8b1, in Nrf2−/− compared with wild-type control mice. The mRNA expression of the bile acid transporters bile salt export pump (Bsep) and organic solute transporter (Ostα) were increased in the face of impaired expression of the multidrug resistance-associated proteins Mrp3 and Mrp4. Deletion of Nrf2 also decreased ileal apical sodium-dependent bile acid transporter (Asbt) expression, leading to reduced bile acid reabsorption and increased loss of bile acid in feces. Finally, when cholestasis is induced by BDL, liver injury was not different from that in wild-type BDL mice. These Nrf2−/− mice also had increased pregnane X receptor (Pxr) and Cyp3a11 mRNA expression in association with enhanced hepatic bile acid hydroxylation. In conclusion, this study finds that Nrf2 plays a major role in the regulation of bile acid homeostasis in the liver and intestine. Deletion of Nrf2 results in a cholestatic phenotype but does not augment liver injury following BDL. PMID:22345550