Outcome of Surgery for Pediatric Gastroesophageal Reflux : Clinical and Endoscopic Follow-up after 300 Fundoplications in 279 Consecutive Patients

Purpose: Clinical and endoscopic assessment of the outcome after fundoplication for pediatric gastroesophageal reflux. Basic procedures: Hospital records of 279 consecutive patients who underwent fundoplication for gastroesophageal reflux from 1991 to 2014 were reviewed. Underlying disorders, clinical and endoscopic findings, imaging studies, pH monitoring, and surgical technique were assessed. Main outcome measures were patency of fundoplication, control of symptoms and esophagitis, complications, redo operations, and predictive factors of failures. Main results: A total of 279 patients underwent 300 fundoplications (277 primaries and 23 redos). Underlying disorders in 217 (72%) patients included neurological impairment (28%) and esophageal atresia (22%). Indications for fundoplication included recalcitrant gastroesophageal reflux symptoms (44%), failure to thrive (22%), respiratory symptoms (15%), esophageal anastomotic stricture (4%), apneic spells (2%), and regurgitation (2%). Preoperative endoscopy was performed in 92% and pH monitoring in 49% of patients. Median age at primary fundoplication was 2.2 ((IQR = 0.5-7.5)) years. Fundoplication was open in 205 (74%; Nissen n=63, Boix-Ochoa n=97, Toupet n=39, and other n=6), laparoscopic in 72 (24%; Nissen n=67 and Toupet n=5), and included hiatoplasty in 73%. Clinical follow-up was a median of 3.9 (IQR = 1.2-9.9) years. Mortality related to surgery was 0.3%. Symptom control was achieved in 87% of patients, and esophagitis rate decreased from 65% to 29% (p Conclusion: The majority of patients who underwent fundoplication had an underlying disorder. Primary fundoplication provided control of symptoms in almost 90% of patients and also reduced the rate of esophagitis. Failure of primary fundoplication occurred in 15% of patients, and an underlying disorder, esophageal atresia, and hiatoplasty increased the risk of failure.Peer reviewe

Cellular Cytoskeleton Dynamics Modulates Non-Viral Gene Delivery through RhoGTPases

Although it is well accepted that the constituents of the cellular microenvironment modulate a myriad of cellular processes, including cell morphology, cytoskeletal dynamics and uptake pathways, the underlying mechanism of how these pathways influence non-viral gene transfer have not been studied. Transgene expression is increased on fibronectin (Fn) coated surfaces as a consequence of increased proliferation, cell spreading and active engagement of clathrin endocytosis pathway. RhoGTPases mediate the crosstalk between the cell and Fn, and regulate cellular processes involving filamentous actin, in-response to cellular interaction with Fn. Here the role of RhoGTPases specifically Rho, Rac and Cdc42 in modulation of non-viral gene transfer in mouse mesenchymal stem (mMSCs) plated in a fibronectin microenvironment was studied. More than 90% decrease in transgene expression was observed after inactivation of RhoGTPases using difficile toxin B (TcdB) and C3 transferase. Expression of dominant negative RhoA (RhoAT19N), Rac1(Rac1T17N) and Cdc42 (Cdc42T17N) also significantly reduced polyplex uptake and transgene expression. Interactions of cells with Fn lead to activation of RhoGTPases. However, further activation of RhoA, Rac1 and Cdc42 by expression of constitutively active genes (RhoAQ63L, Rac1Q61L and Cdc42Q61L) did not further enhance transgene expression in mMSCs, when plated on Fn. In contrast, activation of RhoA, Rac1 and Cdc42 by expression of constitutively active genes for cells plated on collagen I, which by itself did not increase RhoGTPase activation, resulted in enhanced transgene expression. Our study shows that RhoGTPases regulate internalization and effective intracellular processing of polyplexes that results in efficient gene transfer

Is the water footprint an appropriate tool for forestry and forest products: The Fennoscandian case

The water footprint by the Water Footprint Network (WF) is an ambitious tool for measuring human appropriation and promoting sustainable use of fresh water. Using recent case studies and examples from water-abundant Fennoscandia, we consider whether it is an appropriate tool for evaluating the water use of forestry and forest-based products. We show that aggregating catchment level water consumption over a product life cycle does not consider fresh water as a renewable resource and is inconsistent with the principles of the hydrologic cycle. Currently, the WF assumes that all evapotranspiration (ET) from forests is a human appropriation of water although ET from managed forests in Fennoscandia is indistinguishable from that of unmanaged forests. We suggest that ET should not be included in the water footprint of rain-fed forestry and forest-based products. Tools for sustainable water management should always contextualize water use and water impacts with local water availability and environmental sensitivity

Mutation of a single residue, β-glutamate-20, alters protein–lipid interactions of light harvesting complex II

It is well established that assembly of the peripheral antenna complex, LH2, is required for proper photosynthetic membrane biogenesis in the purple bacterium Rhodobacter sphaeroides. The underlying interactions are, as yet, not understood. Here we examined the relationship between the morphology of the photosynthetic membrane and the lipid–protein interactions at the LH2–lipid interface. The non-bilayer lipid, phosphatidylethanolamine, is shown to be highly enriched in the boundary lipid phase of LH2. Sequence alignments indicate a putative lipid binding site, which includes β-glutamate-20 and the adjacent carotenoid end group. Replacement of β-glutamate-20 with alanine results in significant reduction of phosphatidylethanolamine and concomitant raise in phosphatidylcholine in the boundary lipid phase of LH2 without altering the lipid composition of the bulk phase. The morphology of the LH2 housing membrane is, however, unaffected by the amino acid replacement. In contrast, simultaneous modification of glutamate-20 and exchange of the carotenoid sphaeroidenone with neurosporene results in significant enlargement of the vesicular membrane invaginations. These findings suggest that the LH2 complex, specifically β-glutamate-20 and the carotenoids' polar head group, contribute to the shaping of the photosynthetic membrane by specific interactions with surrounding lipid molecules

Sphingomyelin Functions as a Novel Receptor for Helicobacter pylori VacA

The vacuolating cytotoxin (VacA) of the gastric pathogen Helicobacter pylori binds and enters epithelial cells, ultimately resulting in cellular vacuolation. Several host factors have been reported to be important for VacA function, but none of these have been demonstrated to be essential for toxin binding to the plasma membrane. Thus, the identity of cell surface receptors critical for both toxin binding and function has remained elusive. Here, we identify VacA as the first bacterial virulence factor that exploits the important plasma membrane sphingolipid, sphingomyelin (SM), as a cellular receptor. Depletion of plasma membrane SM with sphingomyelinase inhibited VacA-mediated vacuolation and significantly reduced the sensitivity of HeLa cells, as well as several other cell lines, to VacA. Further analysis revealed that SM is critical for VacA interactions with the plasma membrane. Restoring plasma membrane SM in cells previously depleted of SM was sufficient to rescue both toxin vacuolation activity and plasma membrane binding. VacA association with detergent-resistant membranes was inhibited in cells pretreated with SMase C, indicating the importance of SM for VacA association with lipid raft microdomains. Finally, VacA bound to SM in an in vitro ELISA assay in a manner competitively inhibited by lysenin, a known SM-binding protein. Our results suggest a model where VacA may exploit the capacity of SM to preferentially partition into lipid rafts in order to access the raft-associated cellular machinery previously shown to be required for toxin entry into host cells

Ebolavirus Is Internalized into Host Cells via Macropinocytosis in a Viral Glycoprotein-Dependent Manner

Ebolavirus (EBOV) is an enveloped, single-stranded, negative-sense RNA virus that causes severe hemorrhagic fever with mortality rates of up to 90% in humans and nonhuman primates. Previous studies suggest roles for clathrin- or caveolae-mediated endocytosis in EBOV entry; however, ebolavirus virions are long, filamentous particles that are larger than the plasma membrane invaginations that characterize clathrin- or caveolae-mediated endocytosis. The mechanism of EBOV entry remains, therefore, poorly understood. To better understand Ebolavirus entry, we carried out internalization studies with fluorescently labeled, biologically contained Ebolavirus and Ebolavirus-like particles (Ebola VLPs), both of which resemble authentic Ebolavirus in their morphology. We examined the mechanism of Ebolavirus internalization by real-time analysis of these fluorescently labeled Ebolavirus particles and found that their internalization was independent of clathrin- or caveolae-mediated endocytosis, but that they co-localized with sorting nexin (SNX) 5, a marker of macropinocytosis-specific endosomes (macropinosomes). Moreover, the internalization of Ebolavirus virions accelerated the uptake of a macropinocytosis-specific cargo, was associated with plasma membrane ruffling, and was dependent on cellular GTPases and kinases involved in macropinocytosis. A pseudotyped vesicular stomatitis virus possessing the Ebolavirus glycoprotein (GP) also co-localized with SNX5 and its internalization and infectivity were affected by macropinocytosis inhibitors. Taken together, our data suggest that Ebolavirus is internalized into cells by stimulating macropinocytosis in a GP-dependent manner. These findings provide new insights into the lifecycle of Ebolavirus and may aid in the development of therapeutics for Ebolavirus infection

Landscape homogenization due to agricultural intensification disrupts the relationship between reproductive success and main prey abundance in an avian predator

Selecting high-quality habitat and the optimal time to reproduce can increase individual fitness and is a strong evolutionary factor shaping animal populations. However, few studies have investigated the interplay between land cover heterogeneity, limitation in food resources, individual quality and spatial variation in fitness parameters. Here, we explore how individuals of different quality respond to possible mismatches between a cue for prey availability (land cover heterogeneity) and the actual fluctuating prey abundance.Peer reviewe